Godley, Susan Harrington; Meyers, Robert J.; Smith, Jane Ellen; Karvinen, Tracy; Titus, Janet C.; Godley, Mark D.; Dent, George; Passetti, Lora; Kelberg, Pamela
This publication was written for therapists and their supervisors who may want to implement the adolescent community reinforcement approach intervention, which was one of the five interventions tested by the Center for Substance Abuse Treatment's (CSAT's) Cannabis Youth Treatment (CYT) Project. The CYT Project provided funding to support a study…
TERZIC SUPIC, Zorica; SANTRIC MILICEVIC, Milena; SBUTEGA, Isidora; VASIC, Vladimir
Background Adolescence is transitional stage of physical and mental human development occuring between childhood and adult life. Social interactions and environmental factors together are important predictors of adolescent cannabis use. This study aimed to examine the relationship between the social determinants and adolescents behavior with cannabis consumption. Methods: A cross sectional study as part of the European School Survey Project on Alcohol and other Drugs was conducted among 6.150 adolescents aged 16 years in three regions of Serbia, and three types of schools (gymnasium, vocational – professional, and vocational – handicraft) during May – June 2008. A multivariate logistic regression analysis was carried out to obtain adjusted odds ratios with 95% confidence intervals in which the dependent variable was cannabis consumption non-user and user. Results: Among 6.7% of adolescents who had tried cannabis at least one in their lives, boys were more involved in cannabis use than girls, especially boys from gymnasium school. Well off family, lower education of mother, worse relations with parents were significantly associated with cannabis use (P < 0.05). Behaviors like skipping from schools, frequent evening outs, and playing on slot machines were also related to cannabis use (P < 0.05). Conclusions: The study confirmed the importance of family relationship development. Drug use preventive programmes should include building interpersonal trust in a family lifecycle and school culture. PMID:23641402
García-Sánchez, Sara; Matalí, Josep Lluís; Martín-Fernández, María; Pardo, Marta; Lleras, Maria; Castellano-Tejedor, Carmina; Haro, Josep Maria
Cannabis is the illicit substance most widely used by adolescents. Certain personality traits such as impulsivity and sensation seeking, and the subjective effects experienced after substance use (e.g. euphoria or relaxation) have been identified as some of the main etiological factors of consumption. This study aims to categorize a sample of adolescent cannabis users based on their most dominant personality traits (internalizing and externalizing profile). Then, to make a comparison of both profiles considering a set of variables related to consumption, clinical severity and subjective effects experienced. From a cross-sectional design, 173 adolescents (104 men and 69 women) aged 13 to 18 asking for treatment for cannabis use disorder in an Addictive Behavior Unit (UCAD) from the hospital were recruited. For the assessment, an ad hoc protocol was employed to register consumption, the Millon Adolescent Clinical Inventory (MACI) and the Addiction Research Center Inventory (ARCI) 49-item short form were also administered. Factor analysis suggested a two-profile solution: Introverted, Inhibited, Doleful, Dramatizing (-), Egotistic (-), Self-demeaning and Borderline tendency scales composed the internalizing profile, and Submissive (-), Unruly, Forceful, Conforming (-) and Oppositional scales composed the externalizing profile. The comparative analysis showed that the internalizing profile has higher levels of clinical severity and more subjective effects reported than the externalizing profile. These results suggest the need to design specific intervention strategies for each profile.
Liddle, Howard A.
The purpose of the Substance Abuse and Mental Health Services Administration's Center for Substance Abuse Treatment's (CSAT's) Cannabis Youth Treatment (CYT) Project Cooperative Agreement was to test the relative effectiveness and cost-effectiveness of a variety of interventions designed to eliminate marijuana use and associated problems in…
Sampl, Susan; Kadden, Ronald
This manual is designed to help train substance abuse treatment counselors to conduct a brief five-session treatment intervention for adolescents with cannabis use disorders presenting for outpatient treatment. It combines two sessions of motivational enhancement therapy provided individually and three sessions of cognitive behavioral therapy…
Hamilton, Nancy L.; Brantley, Laura Bunch; Tims, Frank M.; Angelovich, Nancy; McDougall, Barbara
Substance-abusing adolescents experiencing inadequate family structure and functioning will be at a serious disadvantage with regard to recovery. The family support network (FSN) intervention seeks to extend the focus of treatment beyond the world of the adolescent by engaging the family, a major system in his or her life. Designed to increase…
Batalla, Albert; Bhattacharyya, Sagnik; Yücel, Murat; Fusar-Poli, Paolo; Crippa, Jose Alexandre; Nogué, Santiago; Torrens, Marta; Pujol, Jesús; Farré, Magí; Martin-Santos, Rocio
Background The growing concern about cannabis use, the most commonly used illicit drug worldwide, has led to a significant increase in the number of human studies using neuroimaging techniques to determine the effect of cannabis on brain structure and function. We conducted a systematic review to assess the evidence of the impact of chronic cannabis use on brain structure and function in adults and adolescents. Methods Papers published until August 2012 were included from EMBASE, Medline, PubMed and LILACS databases following a comprehensive search strategy and pre-determined set of criteria for article selection. Only neuroimaging studies involving chronic cannabis users with a matched control group were considered. Results One hundred and forty-two studies were identified, of which 43 met the established criteria. Eight studies were in adolescent population. Neuroimaging studies provide evidence of morphological brain alterations in both population groups, particularly in the medial temporal and frontal cortices, as well as the cerebellum. These effects may be related to the amount of cannabis exposure. Functional neuroimaging studies suggest different patterns of resting global and brain activity during the performance of several cognitive tasks both in adolescents and adults, which may indicate compensatory effects in response to chronic cannabis exposure. Limitations However, the results pointed out methodological limitations of the work conducted to date and considerable heterogeneity in the findings. Conclusion Chronic cannabis use may alter brain structure and function in adult and adolescent population. Further studies should consider the use of convergent methodology, prospective large samples involving adolescent to adulthood subjects, and data-sharing initiatives. PMID:23390554
de la Serna, Elena; Mayoral, María; Baeza, Inmaculada; Arango, Celso; Andrés, Patricia; Bombin, Igor; González, Cristina; Rapado, Marta; Robles, Olalla; Rodríguez-Sánchez, Jose Manuel; Zabala, Arantzazu; Castro-Fornieles, Josefina
To investigate the relationship between cognition and prior cannabis use in children and adolescents presenting a first episode of psychosis. A total of 107 patients with first episode of psychosis and 96 healthy controls, aged 9 to 17 years, were interviewed about their previous substance use and to assess their cognitive functions. Patients were assessed while not using cannabis by means of a comprehensive neuropsychological battery. They were divided into 2 groups depending on the history of prior cannabis use: cannabis users (CU) and cannabis nonusers (CNU). Significant differences were found in all areas evaluated between the 3 groups. Both CU and CNU patients obtained lower scores than controls on verbal learning and memory and working memory. Patients with prior cannabis use performed better on some tests of attention (Continuous performance test (CPT) number of correct responses, p = 0.002; CPT average reaction time, p < 0.001) and executive functions (Trail Making Test, part B (TMT-B) number of mistakes, p < 0.001; Wisconsin Card Sorting Test (WCST) number of categories completed, p < 0.001) than CNU patients. CU patients performed better than CNU subjects on some cognitive measures. This may indicate lower individual vulnerability for psychosis in CU patients in whom cannabis use can be a precipitating factor of psychotic episodes.
Simpson, Annabelle K; Magid, Viktoriya
Cannabis use in the adolescent population poses a significant threat of addiction potential resulting in altered neurodevelopment. There are multiple mechanisms of treatment of cannabis use disorder including behavioral therapy management and emerging data on treatment via pharmacotherapy. Recognizing the diagnostic criteria for cannabis use disorder, cannabis withdrawal syndrome, and mitigating factors that influence adolescent engagement in cannabis use allows for comprehensive assessment and management in the adolescent population.
Lubman, Dan I; Cheetham, Ali; Yücel, Murat
Heavy cannabis use has been frequently associated with increased rates of mental illness and cognitive impairment, particularly amongst adolescent users. However, the neurobiological processes that underlie these associations are still not well understood. In this review, we discuss the findings of studies examining the acute and chronic effects of cannabis use on the brain, with a particular focus on the impact of commencing use during adolescence. Accumulating evidence from both animal and human studies suggests that regular heavy use during this period is associated with more severe and persistent negative outcomes than use during adulthood, suggesting that the adolescent brain may be particularly vulnerable to the effects of cannabis exposure. As the endocannabinoid system plays an important role in brain development, it is plausible that prolonged use during adolescence results in a disruption in the normative neuromaturational processes that occur during this period. We identify synaptic pruning and white matter development as two processes that may be adversely impacted by cannabis exposure during adolescence. Potentially, alterations in these processes may underlie the cognitive and emotional deficits that have been associated with regular use commencing during adolescence.
Epstein, Katherine A; Kumra, Sanjiv
During late adolescence, progressive cortical thinning occurs in heteromodal association cortex (HASC) that is thought to subserve cognitive development. However, the impact of cannabis use disorder (CUD) upon cortical gray matter development in both healthy adolescents and adolescents with early-onset schizophrenia (EOS) is unclear. T1-weighted magnetic resonance images were acquired from 79 adolescents at baseline and after an 18-month follow-up: 17 with EOS, 17 with CUD, 11 with EOS+CUD, and 34 healthy controls (HC). Mean age at baseline was 16.4years (CUD+) and 17.0years (CUD-). Using FreeSurfer, measures of cortical thickness for ROIs within HASC were obtained. A 2 (EOS versus no EOS)×2 (CUD versus no CUD) multivariate analysis of covariance was applied to change scores from baseline to follow-up to test for main effects of EOS and CUD and an interaction effect. After adjusting for covariates, a significant main effect of CUD was observed. Adolescents with CUD showed an attenuated loss of cortical thickness in the left and right supramarginal, left and right inferior parietal, right pars triangularis, left pars opercularis, left superior frontal, and left superior temporal regions compared to non-using subjects. Stepwise linear regression analysis indicated that greater cumulative cannabis exposure predicted greater cortical thickness in both the left (p=.008) and right (p=.04) superior frontal gyri at study endpoint after adjusting for baseline cortical thickness for the entire sample. These preliminary longitudinal data demonstrate an atypical pattern of cortical development in HASC in adolescents with CUD relative to non-using subjects, across diagnostic groups. Additional studies are needed to replicate these data and to clarify the clinical significance of these findings.
Walker, Denise D; Stephens, Robert; Roffman, Roger; Demarce, Josephine; Lozano, Brian; Towe, Sheri; Berg, Belinda
Cannabis use adversely affects adolescents and interventions that are attractive to adolescents are needed. This trial compared the effects of a brief motivational intervention for cannabis use with a brief educational feedback control and a no-assessment control. Participants were randomized into one of three treatment conditions: Motivational Enhancement Therapy (MET), Educational Feedback Control (EFC), or Delayed Feedback Control (DFC). Those who were assigned to MET and EFC were administered a computerized baseline assessment immediately following randomization and completed assessments at the 3- and 12-month follow-up periods. Participants in the DFC condition were not assessed until the 3-month follow-up. Following the completion of treatment sessions, all participants were offered up to four optional individual treatment sessions aimed at cessation of cannabis use. The research was conducted in high schools in Seattle, Washington. The participant s included 310 self-referred adolescents who smoked cannabis regularly. The main outcome measures included days of cannabis use, associated negative consequences, and engagement in additional treatment. At the 3-month follow-up, participants in both the MET and EFC conditions reported significantly fewer days of cannabis use and negative consequences compared to those in the DFC. The frequency of cannabis use was less in MET relative to EFC at 3 months, but it did not translate to differences in negative consequences. Reductions in use and problems were sustained at 12 months, but there were no differences between MET and EFC interventions. Engagement in additional treatment was minimal and did not differ by condition. Brief interventions can attract adolescent cannabis users and have positive impacts on them, but the mechanisms of the effects are yet to be identified.
Primack, Brian A.; Douglas, Erika L.; Kraemer, Kevin L.
Background Cannabis use is frequently referenced in American popular music, yet it remains uncertain whether exposure to these references is associated with actual cannabis use. We aimed to determine if exposure to cannabis in popular music is independently associated with current cannabis use in a cohort of urban adolescents. Methods We surveyed all 9th grade students at three large U.S. urban high schools. We estimated participants’ exposure to lyrics referent to cannabis with overall music exposure and content analyses of their favorite artists’ songs. Outcomes included current (past 30 day) and ever use of cannabis. We used multivariable regression to assess independent associations between exposures and outcomes while controlling for important covariates. Results Each of the 959 participants was exposed to an estimated 40 cannabis references per day (standard deviation = 104). Twelve percent (N = 108) were current cannabis users and 32% (N=286) had ever used cannabis. Compared with those in the lowest tertile of total cannabis exposure in music, those in the highest tertile of exposure were almost twice as likely to have used cannabis in the past 30 days (odds ratio = 1.83; 95% confidence interval = 1.04, 3.22), even after adjusting for sociodemographic variables, personality characteristics, and parenting style. As expected, however, there was no significant relationship between our cannabis exposure variable and a sham outcome variable of alcohol use. Conclusions This study supports an independent association between exposure to cannabis in popular music and early cannabis use among urban American adolescents. PMID:20039860
McClure, Erin A.; Lydiard, Jessica B.; Goddard, Scott D.; Gray, Kevin M.
Background and Objectives Cannabis is the most widely used illicit substance worldwide, with an estimated 160 million users. Among adolescents, rates of cannabis use are increasing, while the perception of detrimental effects of cannabis use is declining. Difficulty with memory is one of the most frequently noted cognitive deficits associated with cannabis use, but little data exists exploring how well users can identify their own memory deficits, if present. Methods The current secondary analysis sought to characterize objective verbal and visual memory performance via a neurocognitive battery in cannabis-dependent adolescents enrolled in a pharmacotherapeutic cannabis cessation clinical trial (N=112) and compare this to a single self-reported item assessing difficulties with memory loss. Exploratory analyses also assessed dose-dependent effects of cannabis on memory performance. Results A small portion of the study sample (10%) endorsed a “serious problem” with memory loss. Those participants reporting “no problem” or “serious problem” scored similarly on visual and verbal memory tasks on the neurocognitive battery. Exploratory analyses suggested a potential relationship between days of cannabis use, amount of cannabis used, and gender with memory performance. Conclusions and Scientific Significance This preliminary and exploratory analysis suggests that a sub-set of cannabis users may not accurately perceive difficulties with memory. Further work should test this hypothesis with the use of a control group, comprehensive self-reports of memory problems, and adult populations that may have more years of cannabis use and more severe cognitive deficits. PMID:25823635
The Victorian Adolescent Health Cohort Study (VAHCS) is a long-term Australian cohort study that has documented cannabis use in young Australians from the mid-teens to the mid-30s. The study findings have described the natural history of early cannabis use, remission, and escalation and the social and mental health consequences of different patterns of use. The adverse consequences of cannabis use are most clear-cut in heavy early adolescent users. These consequences include educational failure, persisting mental health problems, and progression to other substance use. For later onset and occasional users, the risks are lower and appear to entail modest elevations in risk for other drug use compared with never users. With growing evidence of health consequences, there is a strong case for actions around early heavy adolescent users. Prevention of early use, identification and treatment of early heavy users, and harm reduction through diversion of early heavy users away from the custodial justice system into health care are all priority responses. PMID:27254840
Hoff, Dominic A.; Andersen, Anette; Holstein, Bjorn E.
There is little information available on the topic of poor school satisfaction as a risk factor for cannabis use among adolescents. We examined if there was an association between poor school satisfaction, school class cannabis use and individual cannabis use. Further, we investigated if many cannabis users within the school class statistically…
Malhotra, Anil; Biswas, Parthasarathy
Cannabis is a widely used illicit drug among adolescents, many of whom perceive little risk from cannabis. Cannabis use is associated with poor academic performance and increased school drop-outs. It is also associated with high-risk behaviors in adolescents like crime, violence, unprotected sexual encounters, and car accidents. Many of these…
Chadwick, Benjamin; Miller, Michael L; Hurd, Yasmin L
Cannabis use is increasingly pervasive among adolescents today, even more common than cigarette smoking. The evolving policy surrounding the legalization of cannabis reaffirms the need to understand the relationship between cannabis exposure early in life and psychiatric illnesses. cannabis contains psychoactive components, notably Δ(9)-tetrahydrocannabinol (THC), that interfere with the brain's endogenous endocannabinoid system, which is critically involved in both pre- and post-natal neurodevelopment. Consequently, THC and related compounds could potentially usurp normal adolescent neurodevelopment, shifting the brain's developmental trajectory toward a disease-vulnerable state, predisposing early cannabis users to motivational, affective, and psychotic disorders. Numerous human studies, including prospective longitudinal studies, demonstrate that early cannabis use is associated with major depressive disorder and drug addiction. A strong association between schizophrenia and cannabis use is also apparent, especially when considering genetic factors that interact with this environmental exposure. These human studies set a foundation for carefully controlled animal studies which demonstrate similar patterns following early cannabinoid exposure. Given the vulnerable nature of adolescent neurodevelopment and the persistent changes that follow early cannabis exposure, the experimental findings outlined should be carefully considered by policymakers. In order to fully address the growing issues of psychiatric illnesses and to ensure a healthy future, measures should be taken to reduce cannabis use among teens.
Schmits, Emilie; Maurage, Pierre; Thirion, Romain; Quertemont, Etienne
Cannabis is one of the most commonly drugs used by teenagers. Expectancies about its effects play a crucial role in cannabis consumption. Various tools have been used to assess expectancies, mainly self-report questionnaires measuring explicit expectancies, but implicit measures based on experimental tasks have also been developed, measuring implicit expectancies. The aim of this study was to simultaneously assess implicit/explicit expectancies related to cannabis among adolescent users and non-users. 130 teenagers attending school (55 girls) were enrolled (Age: M=16.40 years); 43.84% had never used cannabis ("non-users") and 56.16% had used cannabis ("users"). They completed self-report questionnaires evaluating cannabis use, cannabis-related problems, effect expectancies (explicit expectancies), alcohol use, social and trait anxiety, depression, as well as three Implicit Association Tests (IAT) assessing implicit expectancies. Adolescents manifested more implicit affective associations (relaxation, excitation, negative) than neutral ones regarding cannabis. These were not related to explicit expectancies. Cannabis users reported more implicit relaxation expectancies and less negative explicit expectancies than non-users. The frequency of use and related problems were positively associated with the explicit expectancies regarding relaxation and enhancement, and were negatively associated with negative explicit expectancies and negative implicit expectancies. Findings indicate that implicit and explicit expectancies play different roles in cannabis use by adolescents. The implications for experimentation and prevention are discussed.
Milin, Robert; Manion, Ian; Dare, Glenda; Walker, Selena
A study to identify and assess the withdrawal symptoms in adolescents afflicted with cannabis dependence is conducted. Results conclude that withdrawal symptoms of cannabis were present in adolescents seeking treatment for this substance abuse.
Loga, Slobodan; Loga-Zec, Svjetlana; Spremo, Mira
There are connection between use of cannabis and many psychiatric disturbances in adolescents, especially "cannabis psychosis", depression, panic attacks and suicide. Negative effects could occur either as a result of a specific pharmacological effect of cannabis, or as the result of stressful experiences during the intoxication of cannabis in young people. Potentially is very dangerous high frequency suicidal ideation among cannabis users.
James, Anthony; James, Christine; Thwaites, Thomas
Cannabis is widely used in adolescence; however, the effects of cannabis on the developing brain remain unclear. Cannabis might be expected to have increased effects upon brain development and cognition during adolescence. There is extensive re-organisation of grey (GM) and white matter (WM) at this time, while the endocannabinoid (eCB) system, which is involved in the normal physiological regulation of neural transmission, is still developing. In healthy adolescent cannabis users there is a suggestion of greater memory loss and hippocampal volume changes. Functional studies point to recruitment of greater brain areas under cognitive load. Structural and DTI studies are few, and limited by comorbid drug and alcohol use. The studies of cannabis use in adolescent-onset schizophrenia (AOS) differ, with one study pointing to extensive GM and WM changes. There is an intriguing suggestion that the left parietal lobe may be more vulnerable to the effects of cannabis in AOS. As in adult schizophrenia cognition does not appear to be adversely affected in AOS following cannabis use. Given the limited number of studies it is not possible to draw firm conclusions. There is a need for adequately powered, longitudinal studies.
Tu, Andrew W.; Ratner, Pamela A.; Johnson, Joy L.
Adolescents' gender-specific cannabis use rates and their correlates were examined. Data were obtained via a cross-sectional survey conducted in 2004 in British Columbia, Canada, funded by the Canadian Institutes of Health Research. School districts were invited to participate, and schools within consenting districts were recruited. In total, 8,225 students (50% male)from Grades 7 to 12 participated. About 73% were “White” and 47% had used cannabis in their lifetime. Cannabis users were grouped according to their frequency of use: “never users” “frequent users” or “heavy users” Male heavy cannabis users (14.3% of boys) were more likely to be in Grade 9 or higher; be Aboriginal; report poorer economic status; never feel like an outsider; frequently use alcohol and tobacco; and have lower satisfaction with family, friends, and school compared with boys that never used. Female heavy users (8.7% of girls) were more likely to be in a higher grade; report poorer economic status, mental health, and academic performance; frequently use alcohol and tobacco; and have lower satisfaction with their school compared with female never users. Three important gender differences in the multivariate analysis of the correlates of cannabis use were noted: school grade (for boys only), Aboriginal status (for boys only), and mental health (for girls only). Despite the limitations of relying on self-reports, a subset of youth appears to be at risk for excessive cannabis use that may impair life opportunities and health. The gender differences may be important in the design and implementation of prevention or treatment programs for adolescents. PMID:18696378
Harvey, Megan A; Sellman, John D; Porter, Richard J; Frampton, Christopher M
Research indicates that cannabis continues to be a popular illegal drug internationally. Furthermore, adolescent rates of use appear to be significant. Whilst the non-acute effect of cannabis use on adult cognition has been extensively researched, there has been less examination of adolescents. This study aimed to investigate the non-acute relationship between cannabis and cognitive function in a sample of adolescents with a continuum of cannabis use, taking into account additional predictor variables (psychiatric functioning, general functioning, demographics and other drug use). Seventy adolescents were recruited from clinical and community sources as well as through newspaper advertisements. After 12 hours abstinence from cannabis, adolescents completed a two-hour interview covering: demographics; alcohol and drug use history; drug use in the past 28 days; depression; further psychiatric functioning (including ADHD and Conduct Disorder); and cognitive functioning as measured by computerised tasks (CANTAB) and traditional pen and paper tests. Adolescents who were regular cannabis users (more than once a week) had a significantly poorer performance on four measures of cognitive function reflecting attention, spatial working memory and learning. Cannabis use remained an independent predictor of performance on the working memory and strategy measures after additional predictor variables were included in a multivariate regression analysis. The results suggest that aspects of adolescent cognitive function are independently related to the frequency of cannabis use beyond acute intoxication.
Lau, Nicholas; Sales, Paloma; Averill, Sheigla; Murphy, Fiona; Sato, Sye-Ok; Murphy, Sheigla
Background Cannabis use is becoming more accepted in mainstream society. In this paper, we use Zinberg’s classic theoretical framework of drug, set, and setting to elucidate how older adult cannabis users managed health, social and legal risks in a context of normalized cannabis use. Methods We present selected findings from our qualitative study of Baby Boomer (born 1946–1964) cannabis users in the San Francisco Bay Area. Data collection consisted of a recorded, in-depth life history interview followed by a questionnaire and health survey. Qualitative interviews were analyzed to discover the factors of cannabis harm reduction from the users’ perspectives. Results Interviewees made harm reduction choices based on preferred cannabis derivatives and routes of administration, as well as why, when, where, and with whom to use. Most interviewees minimized cannabis-related harms so they could maintain social functioning in their everyday lives. Responsible and controlled use was described as moderation of quantity and frequency of cannabis used, using in appropriate settings, and respect for non-users. Users contributed to the normalization of cannabis use through normification. Conclusion Participants followed rituals or cultural practices, characterized by sanctions that helped define “normal” or “acceptable” cannabis use. Users contributed to cannabis normalization through their harm reduction methods. These cultural practices may prove to be more effective than formal legal prohibitions in reducing cannabis-related harms. Findings also suggest that users with access to a regulated market (medical cannabis dispensaries) were better equipped to practice harm reduction. More research is needed on both cannabis culture and alternative routes of administration as harm reduction methods. PMID:25911027
Albertella, Lucy; Norberg, Melissa M
The present study examined mental health symptoms and their relationship to cannabis use and treatment outcomes in a sample of adolescents who received treatment for cannabis dependence through a residential substance use program. The sample included 132 adolescents who nominated cannabis as their primary drug of concern upon admission and who completed at least 30 days of treatment. This study found that mental health symptoms of young cannabis users reduced significantly from admission to three-month follow-up. Further, pretreatment symptoms of anxiety were associated with greater pretreatment cannabis use, while symptoms of phobic anxiety were associated with less pretreatment cannabis use. Pretreatment obsessive-compulsive and somatization symptoms were associated with greater follow-up cannabis use, whereas pretreatment paranoid ideation symptoms were associated with less follow-up cannabis use. Further, follow-up somatization, obsessive-compulsive symptoms, hostility, and phobic anxiety were associated with greater follow-up cannabis use while follow-up symptoms of interpersonal sensitivity were associated with less follow-up cannabis use. These findings highlight a variety of areas for further investigation in order to enhance current treatment for cannabis use.
Wu, Li-Tzy; Swartz, Marvin S.; Brady, Kathleen T.; Hoyle, Rick H.
Due to changes in cannabis policies, concerns about cannabis use (CU) in adolescents have increased. The population of nonwhite groups is growing quickly in the United States. We examined perceived CU norms and their association with CU and CU disorder (CUD) for White, Black, Hispanic, Native-American, Asian-American, Native Hawaiian/Pacific Islander (NH/PI), and mixed-race adolescents. Data were from adolescents (12–17 years) in the 2004–2012 National Surveys on Drug Use and Health (N=163,837). Substance use and CUD were assessed by computer-assisted, self-interviewing methods. Blacks, Hispanics, Native-Americans, and mixed-race adolescents had greater odds of past-year CU and CUD than Whites. Among past-year cannabis users (CUs), Hispanics and Native-Americans had greater odds of having a CUD than Whites. Asian-Americans had the highest prevalence of perceived parental or close friends’ CU disapproval. Native-Americans and mixed-race adolescents had lower odds than Whites of perceiving CU disapproval from parents or close friends. In adjusted analyses, adolescent’s disapproval of CU, as well as perceived disapproval by parents or close friends, were associated with a decreased odds of CU in each racial/ethnic group, except for NHs/PIs. Adolescent’s disapproval of CU was associated with a decreased odds of CUD among CUs for Whites (personal, parental, and close friends’ disapproval), Hispanics (personal, parental, and close friends’ disapproval), and mixed-race adolescents (personal, close friends’ disapproval). Racial/ethnic differences in adolescent CU prevalence were somewhat consistent with adolescents’ reports of CU norm patterns. Longitudinal research on CU health effects should oversample nonwhite adolescents to assure an adequate sample for analysis and reporting. PMID:25795093
Lee, Dustin C.; Crosier, Benjamin S.; Borodovsky, Jacob T.; Sargent, James D.; Budney, Alan J.
Background Along with changes in cannabis laws in the United States and other countries, new products for consuming cannabis are emerging, with unclear public health implications. Vaporizing or “vaping” cannabis is gaining popularity, but little is known about its prevalence or consequences. Methods This study characterized the prevalence and current patterns of vaping cannabis among a large national sample of cannabis users. An online survey was distributed through Facebook ads targeting individuals with interests related to cannabis use. The sample comprised 2,910 cannabis users (age: 18-90, 84% male, 74% Caucasian). Results A majority (61%) endorsed lifetime prevalence of ever vaping, 37% reported vaping in the past 30 days, 20% reported vaping more than 100 lifetime days, and 12% endorsed vaping as their preferred method. Compared to those that had never vaped, vaporizer users were younger, more likely to be male, initiated cannabis at an earlier age, and were less likely to be African American. Those that preferred vaping reported it to be healthier, better tasting, produced better effects, and more satisfying. Only 14% reported a reduction in smoking cannabis since initiating vaping, and only 5% mixed cannabis with nicotine in a vaporizer. Many cannabis users report vaping cannabis, but currently only a small subset prefers vaping to smoking and reports frequent vaping. Conclusion Increases in availability and marketing of vaping devices, and the changing legal status of cannabis in the United States and other countries may influence patterns of use. Frequent monitoring is needed to assess the impact of changing cannabis laws and regulations. PMID:26774946
Fridberg, Daniel J; Skosnik, Patrick D; Hetrick, William P; O’Donnell, Brian F
Chronic cannabis use is associated with residual negative effects on measures of executive functioning. However, little previous work has focused specifically on executive processes involved in performance monitoring in frequent cannabis users. The present study investigated event-related potential (ERP) correlates of performance monitoring in chronic cannabis users. The error-related negativity (ERN) and error positivity (Pe), ERPs sensitive to performance monitoring, were recorded from 30 frequent cannabis users (mean usage=5.52 days/week) and 32 cannabis-naïve control participants during a speeded stimulus discrimination task. The “oddball” P3 ERP was recorded as well. Users and controls did not differ on the amplitude or latency of the ERN; however, Pe amplitude was larger among users. Users also showed increased amplitude and reduced latency of the P3 in response to infrequent stimuli presented during the task. Among users, urinary cannabinoid metabolite levels at testing were unrelated to ERP outcomes. However, total years of cannabis use correlated negatively with P3 latency and positively with P3 amplitude, and age of first cannabis use correlated negatively with P3 amplitude. The results of this study suggest that chronic cannabis use is associated with alterations in neural activity related to the processing of motivationally-relevant stimuli (P3) and errors (Pe). PMID:23427191
Maharajh, Hari D; Konings, Monique
Cannabis use and suicidal behaviour are causes of adolescent morbidity and mortality worldwide. Changing trends in these behaviours in younger age groups, higher incidence, gender differences and sociocultural variations present an enormous challenge. There is no consensus whether these complex relationships are either a direct or an indirect effect due to other mental disorders, or a social response of disclosure of drug taking habits to family members and school authorities. This paper reviews the epidemiology of suicidal behaviour and cannabis use among adolescents and looks at the relationship of these behaviours regionally and internationally. The Caribbean islands have an established use of cannabis with higher suicidal rates, which provides an ideal setting to investigate the interrelationship of these disorders. Preliminary research findings in Trinidad indicate high rates of cannabis use among school students with higher rates in vocational schools compared to grammar schools. Utilising the CAPE questionnaire, depressive and psychotic experiences were common findings in adolescent cannabis users with a significant preponderance of depressive experiences (p<0.01). Our findings suggest that there is a convincing relationship between suicidal behaviour and cannabis use, the latter awakening depressive experiences. Suicidal behaviour and cannabis use are major public health problems and require a multidimensional approach with culturally competent preventive interactions. School based prevention programmes are necessary at the levels of parent-teacher partnership and classroom intervention. The treatment of adolescent disorders remains a major challenge of the future. Double disorders such as cannabis use and suicidal behaviour are uncharted areas and need novel approaches.
Ashtari, Manzar; Avants, Brian; Cyckowski, Laura; Cervellione, Kelly L; Roofeh, David; Cook, Philip; Gee, James; Sevy, Serge; Kumra, Sanjiv
Converging lines of evidence suggest an adverse effect of heavy cannabis use on adolescent brain development, particularly on the hippocampus. In this preliminary study, we compared hippocampal morphology in 14 "treatment-seeking" adolescents (aged 18-20) with a history of prior heavy cannabis use (5.8 joints/day) after an average of 6.7 months of drug abstinence, and 14 demographically matched normal controls. Participants underwent a high-resolution 3D MRI as well as cognitive testing including the California Verbal Learning Test (CVLT). Heavy-cannabis users showed significantly smaller volumes of the right (p < 0.04) and left (p < 0.02) hippocampus, but no significant differences in the amygdala region compared to controls. In controls, larger hippocampus volumes were observed to be significantly correlated with higher CVLT verbal learning and memory scores, but these relationships were not observed in cannabis users. In cannabis users, a smaller right hippocampus volume was correlated with a higher amount of cannabis use (r = -0.57, p < 0.03). These data support a hypothesis that heavy cannabis use may have an adverse effect on hippocampus development. These findings, after an average 6.7 month of supervised abstinence, lend support to a theory that cannabis use may impart long-term structural and functional damage. Alternatively, the observed hippocampal volumetric abnormalities may represent a risk factor for cannabis dependence. These data have potential significance for understanding the observed relationship between early cannabis exposure during adolescence and subsequent development of adult psychopathology reported in the literature for schizophrenia and related psychotic disorders.
Ashtari, Manzar; Avants, Brian; Cyckowski, Laura; Cervellione, Kelly L.; Roofeh, David; Cook, Philip; Gee, James; Sevy, Serge; Kumra, Sanjiv
Converging lines of evidence suggest an adverse effect of heavy cannabis use on adolescent brain development, particularly on the hippocampus. In this preliminary study, we compared hippocampal morphology in 14 “treatment-seeking” adolescents (aged 18-20) with a history of prior heavy-cannabis use (5.8 joints/day) after an average of 6.7 months of drug abstinence, and 14 demographically matched normal controls. Participants underwent a high-resolution 3D MRI as well as cognitive testing including the California Verbal Learning Test (CVLT). Heavy-cannabis users showed significantly smaller volumes of the right (p< .04) and left (p< .02) hippocampus, but no significant differences in the amygdala region compared to controls. In controls, larger hippocampus volumes were observed to be significantly correlated with higher CVLT verbal learning and memory scores, but these relationships were not observed in cannabis users. In cannabis users, a smaller right hippocampus volume was correlated with a higher amount of cannabis use (r= - .57, p< .03). These data support a hypothesis that heavy-cannabis use may have an adverse effect on hippocampus development. These findings, after an average 6.7 month of supervised abstinence, lend support to a theory that cannabis use may impart long-term structural and functional damage. Alternatively, the observed hippocampal volumetric abnormalities may represent a risk factor for cannabis dependence. These data have potential significance for understanding the observed relationship between early cannabis exposure during adolescence and subsequent development of adult psychopathology reported in the literature for schizophrenia and related psychotic disorders. PMID:21296361
Jacobus, Joanna; Tapert, Susan F
This article reviews neuroimaging, neurocognitive, and preclinical findings on the effects of cannabis on the adolescent brain. Marijuana is the second most widely used intoxicant in adolescence, and teens who engage in heavy marijuana use often show disadvantages in neurocognitive performance, macrostructural and microstructural brain development, and alterations in brain functioning. It remains unclear whether such disadvantages reflect pre-existing differences that lead to increased substances use and further changes in brain architecture and behavioral outcomes. Future work should focus on prospective investigations to help disentangle dose-dependent effects from pre-existing effects, and to better understand the interactive relationships with other commonly abused substances (e.g., alcohol) to better understand the role of regular cannabis use on neurodevelopmental trajectories.
Womack, Sean R.; Shaw, Daniel S.; Weaver, Chelsea M.; Forbes, Erika E.
Objective: Previous studies have established a relationship between cannabis use and affective problems among adolescents and young adults; however, the direction of these associations remains a topic of debate. The present study sought to examine bidirectional associations between cannabis use and depressive symptoms, specifically testing the validity of two competing hypotheses: the cannabis effect hypothesis, which suggests that cannabis use contributes to the onset of later depressive symptoms; and the self-medication hypothesis, which posits that individuals increase their use of a substance to alleviate distressing psychological symptoms. Method: Participants in this study were 264 low-socioeconomic-status males assessed at ages 17, 20, and 22. Cross-lag panel models were fit to test bidirectional associations between cannabis use frequency and depressive symptoms across the transition from adolescence to early adulthood. In addition, analyses were conducted within two high-risk subsamples to examine whether associations between cannabis use frequency (ranging from never used to daily use) and depressive symptoms differed among regular cannabis users (used cannabis more than once per week) or subjects reporting at least mild levels of depressive symptoms. Results: Cannabis use and depressive symptoms were concurrently correlated. Cannabis use predicted increases in later depressive symptoms, but only among the mild-depression subsample. Depressive symptoms predicted only slight increases in later cannabis use, among the subsample of regular cannabis users. Conclusions: Temporal patterns of cannabis use and depressive symptoms provide evidence for the cannabis effect but limited evidence for the self-medication hypothesis. Adolescents higher in depressive symptoms may be vulnerable to the adverse psychological effects of using cannabis. Results are discussed in terms of implications for basic research, prevention, and intervention. PMID:26997187
Fairman, Brian J.
Background In most of the world, cannabis smokers mix loose tobacco inside a joint, pipe, spliff, or cone. More recently, a ‘blunt’ formulation combines these two drugs by inserting cannabis into a hollowed-out cigar. Epidemiological research linking simultaneous use of these two drugs and the development of cannabis use disorders (CUD) remains unclear. This study estimates associations linking blunt smoking with levels and subtypes of cannabis problems. Methods Cross-sectional data on 27,767 past-year cannabis users were analyzed from the US National Survey on Drug Use and Health (NSDUH) conducted from 2009–2012. Ten self-reported items of DSM-IV CUD features elicited a single latent trait of cannabis problem (CP) severity, which was then regressed on past-year blunt smoking and past-month blunt frequency measures within the context of a conceptual model. Differential item functioning (DIF) analysis evaluated potential bias in CP feature response by blunt smoking history. Results Past-year blunt smoking was associated with higher CP severity compared to cannabis users who did not smoke blunts. Days of blunt smoking in the past month also predicted higher CP severity than less frequent blunt use. Those smoking blunts experienced more subjectively felt tolerance and having spent more time obtaining or using cannabis, but were less likely to experience other problems, even at the same level of CP severity. Conclusions These findings suggest smoking blunts might promote the development of problematic cannabis use. Responses to cannabis problems differed by history of blunt smoking, possibly implicating an influence of tobacco on measurement of cannabis use disorders. PMID:25746234
Webster, Lauren; Chaiton, Michael; Kirst, Maritt
Background: This study explores the patterns of use and co-use of tobacco and cannabis among Ontario adolescents over 3 decades and if characteristics of co-users and single substance users have changed. Methods: Co-use trends for 1981-2011 were analyzed using the Centre for Addiction and Mental Health Ontario Student Drug Use and Health Survey,…
Shi, Yuyan; Lenzi, Michela; An, Ruopeng
Aims To assess the associations between types of cannabis control policies at country level and prevalence of adolescent cannabis use. Setting, Participants and Design Multilevel logistic regressions were performed on 172,894 adolescents 15 year of age who participated in the 2001/2002, 2005/2006, or 2009/2010 cross-sectional Health Behaviour in School-Aged Children (HBSC) survey in 38 European and North American countries. Measures Self-reported cannabis use status was classified into ever use in life time, use in past year, and regular use. Country-level cannabis control policies were categorized into a dichotomous measure (whether or not liberalized) as well as 4 detailed types (full prohibition, depenalization, decriminalization, and partial prohibition). Control variables included individual-level sociodemographic characteristics and country-level economic characteristics. Findings Considerable intra-class correlations (.15-.19) were found at country level. With respect to the dichotomized cannabis control policy, adolescents were more likely to ever use cannabis (odds ratio (OR) = 1.10, p = .001), use in past year (OR = 1.09, p = .007), and use regularly (OR = 1.26, p = .004). Although boys were substantially more likely to use cannabis, the correlation between cannabis liberalization and cannabis use was smaller in boys than in girls. With respect to detailed types of policies, depenalization was associated with higher odds of past-year use (OR = 1.14, p = .013) and regular use (OR = 1.23, p = .038), and partial prohibition was associated with higher odds of regular use (OR = 2.39, p = .016). The correlation between cannabis liberalization and regular use was only significant after the policy had been introduced for more than 5 years. Conclusions Cannabis liberalization with depenalization and partial prohibition policies was associated with higher levels of regular cannabis use among adolescents. The correlations were heterogeneous between genders and
Mokrysz, C; Freeman, T P; Korkki, S; Griffiths, K; Curran, H V
Preclinical research demonstrates that cannabinoids have differing effects in adolescent and adult animals. Whether these findings translate to humans has not yet been investigated. Here we believe we conducted the first study to compare the acute effects of cannabis in human adolescent (n=20; 16–17 years old) and adult (n=20; 24–28 years old) male cannabis users, in a placebo-controlled, double-blind cross-over design. After inhaling vaporized active or placebo cannabis, participants completed tasks assessing spatial working memory, episodic memory and response inhibition, alongside measures of blood pressure and heart rate, psychotomimetic symptoms and subjective drug effects (for example, ‘stoned', ‘want to have cannabis'). Results showed that on active cannabis, adolescents felt less stoned and reported fewer psychotomimetic symptoms than adults. Further, adults but not adolescents were more anxious and less alert during the active cannabis session (both pre- and post-drug administration). Following cannabis, cognitive impairment (reaction time on spatial working memory and prose recall following a delay) was greater in adults than adolescents. By contrast, cannabis impaired response inhibition accuracy in adolescents but not in adults. Moreover, following drug administration, the adolescents did not show satiety; instead they wanted more cannabis regardless of whether they had taken active or placebo cannabis, while the opposite was seen for adults. These contrasting profiles of adolescent resilience (blunted subjective, memory, physiological and psychotomimetic effects) and vulnerability (lack of satiety, impaired inhibitory processes) show some degree of translation from preclinical findings, and may contribute to escalated cannabis use by human adolescents. PMID:27898071
Peyret, Emmanuelle; Delorme, Richard
A health policy for the prevention and treatment of cannabis-related disorders is urgently needed in France, given the high prevalence of cannabis use among children and adolescents. Such a policy will require a better understanding of the endo-cannabinoid system and the impact of exogenous cannabinoids in this fragile population. The brain continues to undergo significant development until the age of about 25 years, and cannabis consumption by young people therefore carries specific risks of dependence (frequency and intensity), and of neuroanatomical, cognitive and emotional damage. This article summarizes the available data and offers a medical view of the risks and consequences of cannabis use by children and adolescents.
Konings, M; Maharajh, Hari D
Notwithstanding the increase use of cannabis among adolescents in both developing and developed countries, few studies have looked at cannabis use and mood disorders. In a series of case studies, this research project seeks to investigate patterns of clinical presentations seen among cannabis users in psychiatric outpatients in Trinidad. Five clinical patterns of presentations are identified among cannabis users and abusers based on variables of dosing, age of initial use, duration of use, tolerance and reverse tolerance and poly-drug abuse. All patients in these case studies were standardized for method of use and potency of cannabis used. Patients were screened by urine tests to determine co-morbid use of other substances. Other variables such as environmental factors and genetic vulnerability were reviewed as far as possible from historical accounts of family members. The five patterns described are low, controlled use with mild euphoria and heightened awareness, moderate use with mixed depressive symptoms and suicidal behaviour, heavy, short term use with manic symptoms, long term incremental use with psychotic symptoms due to the trumping of depressive symptoms and cannabis mixed with other substances resulting in florid psychosis. Mood disorders appear to be a common finding among adolescents using cannabis. Sensitization to symptomatic presentation and early detection of cannabis use in young adolescents are necessary. Further research is needed on the effect of cannabinoids on emotions, behaviour and thinking and its relationship to mental disorders. This study is useful as a guideline for the implementation of public health strategies and legislation concerning the use of cannabis in youths.
McGarvey, Elizabeth L; Leon-Verdin, MaGuadalupe; Bloomfield, Karen; Wood, Sharon; Winters, Esther; Smith, Jennifer
An evidence-based treatment for adolescent cannabis users, Adolescent Community Reinforcement Approach with Assertive Continuing Care, was implemented in a rural county and small city in the USA. A total of 147 adolescents, ages 12-18, were enrolled and assessed at baseline and three time points: 3, 6, and 12 months using the Global Appraisal of Individual Needs and related measures. Program effectiveness was confirmed. The treatment was equally effective for youth from the city versus the county. More than two-thirds (68.7%) of the adolescents reported quitting use of cannabis by 12 months. The days of cannabis use in the last 90 days decreased significantly from the first follow-up, controlling for age (p value < .01), and shows consistent decline until the end of the treatment. In addition to reduction in substance use, the average number of days missing school and expelled from school decreased significantly from baseline to the end of the treatment.
Aims: To investigate the links between the visibility of cannabis use in school (measured by teachers' reports of students being under the influence of cannabis on school premises), the proportion of cannabis users in the class, perceived availability of cannabis, as well as adolescent cannabis use. Methods: A multilevel regression model was…
Blecha, L; Benyamina, A; Reynaud, M
Cannabis is the most frequently used illegal drug in France. In 2007, the average age for a first use was 15.1 years. Most teenagers will limit their use to a few experiences or controlled use. However, for those who do become dependent, the lapse between the first use and dependence is brief (approximately 18 months) with an average of 28 months compared to tobacco (3-5 years) and alcohol (5-9 years). In light of this brief delay, it is crucial to quickly recognize adolescents who have problem cannabis use and to educate parents to warning signs and to teach them how to efficiently discuss the subject with their teenager. Multidimensional Family Therapy, Cognitive and Behavioral Family Therapy and Brief Strategic Family Therapy have shown their efficacy in clinical trials. Improving family dynamics represents not only a motivational opportunity to help the adolescent to adhere to drug dependence treatment, but may also facilitate reintegration into a drug-free social environment and maintenance in a drug-free existence. Family interventions have been shown to be even more effective when community family assistance relations (social workers, educational counselors) are optimized. Family therapy should also be combined with personal empowerment and life planning interventions which enable the adolescent to increase his self-esteem through scholastic and professional achievement.
Shakoor, Sania; Zavos, Helena M S; McGuire, Philip; Cardno, Alastair G; Freeman, Daniel; Ronald, Angelica
Cannabis users are more likely to have psychotic experiences (PEs). The degree to which these associations are driven by genetic or environmental influences in adolescence is unknown. This study estimated the genetic and environmental contributions to the relationship between cannabis use and PEs. Specific PEs were measured in a community-based twin sample (4830 16-year-old pairs) using self-reports and parent-reports. Adolescents reported on ever using cannabis. Multivariate liability threshold structural equation model-fitting was conducted. Cannabis use was significantly correlated with PEs. Modest heritability (37%), common environmental influences (55%) and unique environment (8%) were found for cannabis use. For PEs, modest heritability (27-54%), unique environmental influences (E=12-50%) and little common environmental influences (11-20%), with the exception of parent-rated Negative Symptoms (42%), were reported. Environmental influences explained all of the covariation between cannabis use and paranoia, cognitive disorganization and parent-rated negative symptoms (bivariate common environment=69-100%, bivariate unique environment=28-31%), whilst the relationship between cannabis use and hallucinations indicated familial influences. Cannabis use explains 2-5% of variance in positive, cognitive, and negative PEs. Cannabis use and psychotic experience co-occur due to environmental factors. Focus on specific environments may reveal why adolescent cannabis use and psychotic experiences tend to 'travel together'.
Dinieri, Jennifer A; Hurd, Yasmin L
Marijuana (Cannabis sativa) is the illicit drug most commonly used by two vulnerable populations relevant to neurodevelopment-pregnant women and teenagers. Human longitudinal studies have linked prenatal and adolescent cannabis exposure with long-term behavioral abnormalities as well as increased vulnerability to neuropsychiatric disorders in adulthood. Animal models provide a means of studying the neurobiological mechanisms underlying these long-term effects. This chapter provides an overview of the animal models we have used to study the developmental impact of cannabis.
Herrmann, Evan S; Weerts, Elise M; Vandrey, Ryan
Over 300,000 individuals enter treatment for cannabis-use disorders (CUDs) in the United States annually. Cannabis withdrawal is associated with poor CUD-treatment outcomes, but no prior studies have examined sex differences in withdrawal among treatment-seeking cannabis users. Treatment-seeking cannabis users (45 women and 91 men) completed a Marijuana Withdrawal Checklist (Budney, Novy, & Hughes, 1999, Budney, Moore, Vandrey, & Hughes, 2003) at treatment intake to retrospectively characterize withdrawal symptoms experienced during their most recent quit attempt. Scores from the 14-item Composite Withdrawal Discomfort Scale (WDS), a subset of the Marijuana Withdrawal Checklist that corresponds to valid cannabis withdrawal symptoms described in the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; APA, 2013) were calculated. Demographic and substance-use characteristics, overall WDS scores, and scores on individual WDS symptoms were compared between women and men. Women had higher overall WDS scores than men, and women had higher scores than men on 6 individual symptoms in 2 domains, mood symptoms (i.e., irritability, restlessness, increased anger, violent outbursts), and gastrointestinal symptoms (i.e., nausea, stomach pain). Follow-up analyses isolating the incidence and severity of WDS symptoms demonstrated that women generally reported a higher number of individual withdrawal symptoms than men, and that they reported experiencing some symptoms as more severe. This is the first report to demonstrate that women seeking treatment for CUDs may experience more withdrawal then men during quit attempts. Prospective studies of sex differences in cannabis withdrawal are warranted.
Cousijn, Janna; Goudriaan, Anna E.; Ridderinkhof, K. Richard; van den Brink, Wim; Veltman, Dick J.; Wiers, Reinout W.
A potentially powerful predictor for the course of drug (ab)use is the approach-bias, that is, the pre-reflective tendency to approach rather than avoid drug-related stimuli. Here we investigated the neural underpinnings of cannabis approach and avoidance tendencies. By elucidating the predictive power of neural approach-bias activations for future cannabis use and problem severity, we aimed at identifying new intervention targets. Using functional Magnetic Resonance Imaging (fMRI), neural approach-bias activations were measured with a Stimulus Response Compatibility task (SRC) and compared between 33 heavy cannabis users and 36 matched controls. In addition, associations were examined between approach-bias activations and cannabis use and problem severity at baseline and at six-month follow-up. Approach-bias activations did not differ between heavy cannabis users and controls. However, within the group of heavy cannabis users, a positive relation was observed between total lifetime cannabis use and approach-bias activations in various fronto-limbic areas. Moreover, approach-bias activations in the dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC) independently predicted cannabis problem severity after six months over and beyond session-induced subjective measures of craving. Higher DLPFC/ACC activity during cannabis approach trials, but lower activity during cannabis avoidance trials were associated with decreases in cannabis problem severity. These findings suggest that cannabis users with deficient control over cannabis action tendencies are more likely to develop cannabis related problems. Moreover, the balance between cannabis approach and avoidance responses in the DLPFC and ACC may help identify individuals at-risk for cannabis use disorders and may be new targets for prevention and treatment. PMID:22957019
Investigated possible links between normative and political opposition, mental health, and the use of cannabis in prospective longitudinal study of Norwegian adolescents (n=1,311). Findings indicated that the group that experimented with cannabis was mainly characterized by political and normative "oppositional" engagement, but heavy…
Hanna, Rebecca C; Shalvoy, Alexandra; Cullum, C Munro; Ivleva, Elena I; Keshavan, Matcheri; Pearlson, Godfrey; Hill, S Kristian; Sweeney, John A; Tamminga, Carol A; Ghose, Subroto
Prior cannabis use, compared to nonuse, is reported to be associated with less cognitive impairment in schizophrenia. The age of cannabis use and the persistent influence of cannabis use on cognitive function has not been examined across the psychosis dimension. Ninety-seven volunteers with psychosis (schizophrenia, schizoaffective, or bipolar psychosis) and 64 controls were recruited at the Dallas site of the Bipolar-Schizophrenia Network on Intermediate Phenotypes consortium. Cannabis use history obtained in a semi-structured manner was used to categorize subjects into nonusers, adolescent-onset users, and late-onset users. The a priori hypothesis tested was that individuals with psychosis and a history of adolescent cannabis use (ACU) would have better global neuropsychological performance, as measured by the Brief Assessment of Cognition in Schizophrenia (BACS) battery, compared to those with psychosis and no cannabis use history. BACS Composite scores were significantly higher in individuals with psychosis with ACU compared to individuals with psychosis and no prior cannabis use. In subgroup analyses, ACU influenced global cognition in the schizophrenia/schizoaffective (SCZ) subgroup but not the bipolar psychosis subgroup. Exploratory analyses within the SCZ group, suggest that ACU was associated with better performance in specific domains compared to non-ACU groups. There are distinct associations between age of cannabis use and neuropsychological function across psychotic illnesses. Specifically, ACU is associated with better cognitive function in SCZ but not bipolar psychosis. This age-dependent and diagnosis-specific influence of cannabis may need to be factored into the design of future cognitive studies in SCZ.
Ammerman, Seth; Tau, Gregory
The use of cannabis for both legal (similar to alcohol) and medical purposes is becoming more common. Although cannabis remains an illegal Schedule 1 drug federally, as of November 2015, 23 states and the District of Columbia have legalized "medical" cannabis, and 4 states and the District of Columbia have legalized the use of cannabis for adults aged 21 years and older. It is very likely that more and more states will sooner rather than later allow cannabis for both medical and legal purposes. This review article will focus on a variety of issues relevant to the current debate about cannabis, and will address the following.
Buckner, Julia D.; Zvolensky, Michael J.; Crosby, Ross D.; Wonderlich, Stephen A.; Ecker, Anthony H.; Richter, Ashley
Background Cannabis remains the most commonly used illicit substance and use rates are rising. Notably, the prevalence of cannabis use disorders (CUD) nearly equals that of other illicit substance use disorders combined. Thus, the present study aimed to identify cognitive, affective, and situational predictors and consequences of ad-lib cannabis use in a racially diverse sample. Methods The sample consisted of 93 current cannabis users (34.4% female; 57.1% non-Hispanic Caucasian), 87.1% of whom evinced a current CUD. Ecological momentary assessment was used to collect frequent ratings of cannabis withdrawal, craving, affect, cannabis use motives, and peer cannabis use over two weeks. Mixed effects linear models examined within- and between-day correlates and consequences of cannabis use. Results Withdrawal and craving were higher on cannabis use days than non-use days. Withdrawal, craving, and positive and negative affect were higher immediately prior to cannabis use compared to non-use episodes. Withdrawal and craving were higher among those who subsequently used cannabis than those who did not. Cannabis use resulted in less subsequent withdrawal, craving, and negative affect. Enhancement and coping motives were the most common reasons cited for use. Withdrawal and negative affect were related to using cannabis for coping motives and social motives. Participants were most likely to use cannabis if others were using, and withdrawal and craving were greater in social situations when others were using. Conclusions Data support the contention that cannabis withdrawal and craving and affect and peer use play important roles in the maintenance of cannabis use. PMID:25578250
Coffey, Carolyn; Patton, George C
The Victorian Adolescent Health Cohort Study (VAHCS) is a long-term Australian cohort study that has documented cannabis use in young Australians from the mid-teens to the mid-30s. The study findings have described the natural history of early cannabis use, remission, and escalation and the social and mental health consequences of different patterns of use. The adverse consequences of cannabis use are most clear-cut in heavy early adolescent users. These consequences include educational failure, persisting mental health problems, and progression to other substance use. For later onset and occasional users, the risks are lower and appear to entail modest elevations in risk for other drug use compared with never users. With growing evidence of health consequences, there is a strong case for actions around early heavy adolescent users. Prevention of early use, identification and treatment of early heavy users, and harm reduction through diversion of early heavy users away from the custodial justice system into health care are all priority responses.
Troup, Lucy J; Andrzejewski, Jeremy A; Braunwalder, Jacob T; Torrence, Robert D
As part of an ongoing research program into the relationship between cannabis use and emotion processing, participants were assessed on their level of cannabis exposure using the Recreational Cannabis Use Examination, a measure developed specifically to assess cannabis use in Colorado post state legalization. Three groups were created based on self-reported use: a control group who have never used, a casual user group and a chronic user group. Each participant also completed two measures of mood assessment, the Center for Epidemiologic Studies Depression Scale and the State-Trait Anxiety Inventory. Relationships between cannabis use groups and scores on these measures were then analyzed using both correlations and multivariate analysis of variance. Results indicate a relationship between casual cannabis use and scoring highly for depressive symptomatology on the Center for Epidemiologic Studies Depression Scale. There were no significant relationships between cannabis use and scores on the State-Trait Anxiety Inventory.
Andrzejewski, Jeremy A.; Braunwalder, Jacob T.; Torrence, Robert D.
As part of an ongoing research program into the relationship between cannabis use and emotion processing, participants were assessed on their level of cannabis exposure using the Recreational Cannabis Use Examination, a measure developed specifically to assess cannabis use in Colorado post state legalization. Three groups were created based on self-reported use: a control group who have never used, a casual user group and a chronic user group. Each participant also completed two measures of mood assessment, the Center for Epidemiologic Studies Depression Scale and the State-Trait Anxiety Inventory. Relationships between cannabis use groups and scores on these measures were then analyzed using both correlations and multivariate analysis of variance. Results indicate a relationship between casual cannabis use and scoring highly for depressive symptomatology on the Center for Epidemiologic Studies Depression Scale. There were no significant relationships between cannabis use and scores on the State-Trait Anxiety Inventory. PMID:27957402
Jager, Gerry; Block, Robert I.; Luijten, Maartje; Ramsey, Nick F.
Adolescents' risk-taking behavior has been linked to a maturational imbalance between reward (“go”) and inhibitory-control (“stop”) related brain circuitry. This may drive adolescent drug-taking, such as cannabis use. In this study we assessed the non-acute effects of adolescent cannabis use on reward-related brain function. We performed a two-site (United States and Netherlands; pooled data) functional magnetic resonance imaging (fMRI) study with a cross-sectional design. Twenty-one abstinent but frequent cannabis-using boys were compared with 24 non-using peers on reward-related brain function, using a monetary incentive delay task with fMRI. Focus was on anticipatory and response stages of reward and brain areas critically involved in reward processing like the striatum. Performance in users was normal. Region-of-interest analysis indicated striatal hyperactivity during anticipatory stages of reward in users. Intriguingly, this effect was most pronounced during non-rewarding events. Striatal hyperactivity in adolescent cannabis users may signify an overly sensitive motivational brain circuitry. Frequent cannabis use during adolescence may induce diminished ability to disengage the motivational circuit when no reward can be obtained. This could strengthen the search for reinforcements like drugs of abuse, even when facing the negative (non-rewarding) consequences. PMID:23909003
Soueif, M I
Twelve objective tests, generating 16 psychological test variables were administered to 850 chronic cannabis takers and 839 non-takers, all Egyptian males, ranging in age between 15 and 50 years, and representing various positions on continua of literacy-illiteracy and urbanism-ruralism. The tests were intended to assess different modalities of 5 broad psychological functions: speed of psychomotor performance, estimation of moderate distances, estimation of a few minutes time interval, immediate memory for digits and designs and visual-motor co-ordination. Analysis of variance based on 3 x 3 x 2 factorial design was carried out and revealed statistically significant differences between the two groups of subjects on most of the test variables. Detailed analyses showed that controls displayed better performance than drug users on the majority of the variables. Significant second order interaction effects emerged in a big number of cases denoting that, under certain conditions relating to literacy-illiteracy and urbanism-ruralism, the superiority of controls over cannabis users became much more impressive. Our findings were discussed in the light of investigations which were conducted on the psychological correlates and/or effects of long term and short term cannabis consumption. The clinical psychological literature was cited where slowness of psychomotor performance, defective visual-motor co-ordination and impaired memory for designs were reported to be associated with psychiatric disorder. It is suggested that our results point to meaningful associations between chronic cannabis consumption and manifestations of psychopathology.
Novak, Scott P.; Peiper, Nicholas C.; Zarkin, Gary A.
Background This study examined poly-drug use involving the use of cannabis with nonmedical prescription pain reliever use (NMPR) and alcohol use. Methods Computer-assisted survey data from the National Survey on Drug Use and Health were examined. The NSDUH is an annual, cross-sectional survey of non-institutionalized citizens in the United States (ages 12+). Replicate analyses were conducted using the 2013 and 2003 survey waves. Results Higher levels of cannabis use were consistently associated with more frequent consumption of prescription pain relievers, with findings replicating in both 2013 and 2003. While the prevalence of dual users declined from 2003 (2.5%) to 2013 (2.3%), the average number of days used among dual users increased by an average of 20 days over that period. These changes largely occurred among those aged 35 or older, males, whites, and non-illicit drug users. Past-year marijuana use increased by 16% (10.8–12.6%, p-value < .001) whereas NMPR decreased by 15% (4.9–4.2%, p-value < .001). The largest changes occurred after 2011. Persons using the most cannabis generally had higher levels of alcohol use relative to those using the least amount of cannabis. There was a significant increase in the prevalence of dual use between 2003 (10.2%) and 2013 (11.6%), while the prevalence of past-year alcohol use remained relatively stable. Conclusions Clinical efforts and public health interventions should consider the possible co-ingestion of cannabis with NMPR and alcohol, as concomitant use may portend negative health effects in the short and long-term. PMID:26748409
Jones, Sandra C.; Rossiter, John R.
This paper examines the believability of strong warnings about the negative consequences of drug use among young adults in Australia who have never tried, currently use, or have tried and rejected cannabis. It finds that the strong warnings about cannabis are generally believed by never-triers. The same warnings are perceived by current users as…
Gray, Kevin M.; Riggs, Paula D.; Min, Sung-Joon; Mikulich-Gilbertson, Susan K.; Bandyopadhyay, Dipankar; Winhusen, Theresa
Background Cigarette smoking is common in adolescents with attention-deficit/hyperactivity disorder (ADHD) and substance use disorders (SUD). However, little is known about the relationship between cigarette and cannabis use trajectories in the context of treatment for both ADHD and SUD. To address this research gap, we report collateral analyses from a 16-week randomized, controlled trial (n=303) of osmotic-release methylphenidate (OROS-MPH) in adolescents with ADHD concurrently receiving cognitive behavioral therapy (CBT) targeting non-nicotine SUD. Methods Participants completed cigarette and cannabis use self-report at baseline and throughout treatment. Analyses were performed to explore the relationships between cigarette smoking, cannabis use, and other factors, such as medication treatment assignment (OROS-MPH versus placebo). Results Baseline (pre-treatment) cigarette smoking was positively correlated with cannabis use. Negligible decline in cigarette smoking during treatment for non-nicotine SUD was observed in both medication groups. Regular cigarette and cannabis users at baseline who reduced their cannabis use by >50% also reduced cigarette smoking (from 10.8±1.1 to 6.2±1.1 cigarettes per day). Conclusions Findings highlight the challenging nature of concurrent cannabis and cigarette use in adolescents with ADHD, but demonstrate that changes in use of these substances during treatment may occur in parallel. PMID:21411243
Kowal, Mikael A.; Colzato, Lorenza S.; Hommel, Bernhard
Chronic cannabis use has been shown to block long-term depression of GABA-glutamate synapses in the striatum, which is likely to reduce the extent to which endogenous cannabinoids modulate GABA- and glutamate-related neuronal activity. The current study aimed at investigating the effect of this process on striatal dopamine levels by studying the spontaneous eye blink rate (EBR), a clinical marker of dopamine level in the striatum. 25 adult regular cannabis users and 25 non-user controls matched for age, gender, race, and IQ were compared. Results show a significant reduction in EBR in chronic users as compared to non-users, suggesting an indirect detrimental effect of chronic cannabis use on striatal dopaminergic functioning. Additionally, EBR correlated negatively with years of cannabis exposure, monthly peak cannabis consumption, and lifetime cannabis consumption, pointing to a relationship between the degree of impairment of striatal dopaminergic transmission and cannabis consumption history. PMID:22125599
Bender, Kimberly; Tripodi, Stephen J.; Sarteschi, Christy; Vaughn, Michael G.
Objective: This meta-analytic review assesses the effectiveness of substance abuse interventions to reduce adolescent cannabis use. Method: A systematic search identified 15 randomized controlled evaluations of interventions to reduce adolescent cannabis use published between 1960 and 2008. The primary outcome variables, frequency of cannabis use,…
Di Forti, Marta; Sallis, Hannah; Allegri, Fabio; Trotta, Antonella; Ferraro, Laura; Stilo, Simona A.; Marconi, Arianna; La Cascia, Caterina; Reis Marques, Tiago; Pariante, Carmine; Dazzan, Paola; Mondelli, Valeria; Paparelli, Alessandra; Kolliakou, Anna; Prata, Diana; Gaughran, Fiona; David, Anthony S.; Morgan, Craig; Stahl, Daniel; Khondoker, Mizanur; MacCabe, James H.; Murray, Robin M.
Cannabis use is associated with an earlier age of onset of psychosis (AOP). However, the reasons for this remain debated. Methods: We applied a Cox proportional hazards model to 410 first-episode psychosis patients to investigate the association between gender, patterns of cannabis use, and AOP. Results: Patients with a history of cannabis use presented with their first episode of psychosis at a younger age (mean years = 28.2, SD = 8.0; median years = 27.1) than those who never used cannabis (mean years = 31.4, SD = 9.9; median years = 30.0; hazard ratio [HR] = 1.42; 95% CI: 1.16–1.74; P < .001). This association remained significant after controlling for gender (HR = 1.39; 95% CI: 1.11–1.68; P < .001). Those who had started cannabis at age 15 or younger had an earlier onset of psychosis (mean years = 27.0, SD = 6.2; median years = 26.9) than those who had started after 15 years (mean years = 29.1, SD = 8.5; median years = 27.8; HR = 1.40; 95% CI: 1.06–1.84; P = .050). Importantly, subjects who had been using high-potency cannabis (skunk-type) every day had the earliest onset (mean years = 25.2, SD = 6.3; median years = 24.6) compared to never users among all the groups tested (HR = 1.99; 95% CI: 1.50- 2.65; P < .0001); these daily users of high-potency cannabis had an onset an average of 6 years earlier than that of non-cannabis users. Conclusions: Daily use, especially of high-potency cannabis, drives the earlier onset of psychosis in cannabis users. PMID:24345517
Verdejo-García, Antonio; Beatriz Fagundo, Ana; Cuenca, Aida; Rodriguez, Joan; Cuyás, Elisabet; Langohr, Klaus; de Sola Llopis, Susana; Civit, Ester; Farré, Magí; Peña-Casanova, Jordi; de la Torre, Rafael
The adverse effects of cannabis use on executive functions are still controversial, fostering the need for novel biomarkers able to unveil individual differences in the cognitive impact of cannabis consumption. Two common genetic polymorphisms have been linked to the neuroadaptive impact of Δ9-tetrahydrocannabinol (THC) exposure and to executive functions in animals: the catechol-O-methyltransferase (COMT) gene val158met polymorphism and the SLC6A4 gene 5-HTTLPR polymorphism. We aimed to test if these polymorphisms moderate the harmful effects of cannabis use on executive function in young cannabis users. We recruited 144 participants: 86 cannabis users and 58 non-drug user controls. Both groups were genotyped and matched for genetic makeup, sex, age, education, and IQ. We used a computerized neuropsychological battery to assess different aspects of executive functions: sustained attention (CANTAB Rapid Visual Information Processing Test, RVIP), working memory (N-back), monitoring/shifting (CANTAB ID/ED set shifting), planning (CANTAB Stockings of Cambridge, SOC), and decision-making (Iowa Gambling Task, IGT). We used general linear model-based analyses to test performance differences between cannabis users and controls as a function of genotypes. We found that: (i) daily cannabis use is not associated with executive function deficits; and (ii) COMT val158met and 5-HTTLPR polymorphisms moderate the link between cannabis use and executive performance. Cannabis users carrying the COMT val/val genotype exhibited lower accuracy of sustained attention, associated with a more strict response bias, than val/val non-users. Cannabis users carrying the COMT val allele also committed more monitoring/shifting errors than cannabis users carrying the met/met genotype. Finally, cannabis users carrying the 5-HTTLPR s/s genotype had worse IGT performance than s/s non-users. COMT and SLC6A4 genes moderate the impact of cannabis use on executive functions. PMID:23449176
Hartman, Christie A.; Gelhorn, Heather; Crowley, Thomas J.; Sakai, Joseph T.; Stallings, Michael; Young, Susan E.; Rhee, Soo Hyun; Corley, Robin; Hewitt, John K.; Hopfer, Christian J.
A study to examine the DSM-IV criteria for cannabis abuse and dependence among adolescents is conducted. Results conclude that abuse and dependence criteria were not found to affect the different levels of severity in cannabis use.
Woodruff, Susan I.; McCabe, Cameron T.; Hohman, Melinda; Clapp, John D.; Shillington, Audrey M.; Eisenberg, Kimberly; Sise, C. Beth; Castillo, Edward M.; Chan, Theodore C.; Sise, Michael J.
Abstract Emergency department (ED) settings have gained interest as venues for illegal drug misuse prevention and intervention, with researchers and practitioners attempting to capitalize on the intersection of need and opportunity within these settings. This study of 686 adult patients visiting two EDs for various reasons who admitted drug use compared daily cannabis-only users, nondaily cannabis-only users, and other drug users on sociodemographic and drug-related severity outcomes. The three drug use groups did not differ on most sociodemographic factors or medical problem severity scores. Forty-five percent of the sample was identified as having a drug use problem. ED patients who used drugs other than cannabis were at particular risk for high drug use severity indicators and concomitant problems such as psychiatric problems and alcohol use severity. However, 19–29% of cannabis-only users were identified as having problematic drug use. Furthermore, daily cannabis-only users fared less well than nondaily cannabis users with regard to drug use severity indicators and self-efficacy for avoiding drug use. Results may assist emergency medicine providers and medical social workers in matching patients to appropriate intervention. For example, users of drugs other than cannabis (and perhaps heavy, daily cannabis-only users) may need referral to specialty services for further assessment. Enhancement of motivation and self-efficacy beliefs could be an important target of prevention and treatment for cannabis-only users screened in the ED. PMID:27689138
Looby, Alison; Earleywine, Mitch
Research reveals mixed results for the effects of cannabis on cognitive functioning. These divergent results might stem from stereotype threat (ST), which occurs when individuals believe that a group to which they belong is inferior, resulting in poor test performance. Widespread media coverage of purported cannabis-related deficits in cognitive functioning may elicit ST among cannabis users, particularly among men, who may be more likely than women to identify with the cannabis-user stereotype. To investigate this hypothesis, cannabis users (30 male, 27 female) read a summary of research indicating either that cannabis produced deficits (ST condition), or that cannabis actually created no changes in cognitive functions. Participants then completed cognitive tests. Examination of the gender x condition interaction revealed significant results on 4 tests: the California Verbal Learning Test-II immediate recall task, the Controlled Oral Word Association Test for number of words generated and number of switches between clusters, and the Digit Symbol Substitution Task. Males exposed to ST performed worse on all tests compared to men not exposed to ST, while women exposed to ST performed better than women not exposed. These results suggest that cognitive deficits observed in male cannabis users may be attributed to ST rather than decreased functioning. Surprisingly, women in the ST condition scored higher than controls. Perhaps female users do not identify with the typical cannabis stereotype. This study highlights the importance of disconfirming relevant stereotypes prior to examination of the cognitive abilities of cannabis users.
Cohen, Martin; Rasser, Paul E; Peck, Greg; Carr, Vaughan J; Ward, Philip B; Thompson, Paul M; Johnston, Patrick; Baker, Amanda; Schall, Ulrich
Epidemiological data link adolescent cannabis use to psychosis and schizophrenia, but its contribution to schizophrenia neuropathology remains controversial. First-episode schizophrenia (FES) patients show regional cerebral grey- and white-matter changes as well as a distinct pattern of regional grey-matter loss in the vermis of the cerebellum. The cerebellum possesses a high density of cannabinoid type 1 receptors involved in the neuronal diversification of the developing brain. Cannabis abuse may interfere with this process during adolescent brain maturation leading to 'schizophrenia-like' cerebellar pathology. Magnetic resonance imaging and cortical pattern matching techniques were used to investigate cerebellar grey and white matter in FES patients with and without a history of cannabis use and non-psychiatric cannabis users. In the latter group we found lifetime dose-dependent regional reduction of grey matter in the right cerebellar lobules and a tendency for more profound grey-matter reduction in lobule III with younger age at onset of cannabis use. The overall regional grey-matter differences in cannabis users were within the normal variability of grey-matter distribution. By contrast, FES subjects had lower total cerebellar grey-matter:total cerebellar volume ratio and marked grey-matter loss in the vermis, pedunculi, flocculi and lobules compared to pair-wise matched healthy control subjects. This pattern and degree of grey-matter loss did not differ from age-matched FES subjects with comorbid cannabis use. Our findings indicate small dose-dependent effects of juvenile cannabis use on cerebellar neuropathology but no evidence of an additional effect of cannabis use on FES cerebellar grey-matter pathology.
Hughes, John R.; Naud, Shelly; Budney, Alan J.; Fingar, James R.; Callas, Peter W.
Introduction We tested whether environmental cues prompt or inhibit quit or reduction attempts among heavy cannabis users. Methods We recruited 196 daily cannabis users who intended to stop or reduce at some point in the next 3 months. Users called an Interactive Voice Response system daily over 3 months to report on cues that might prompt an attempt to quit or reduce (e.g., a request to stop), cues that might inhibit a quit/reduction attempt (e.g., someone offering cannabis), cannabis use, and attempts to stop or reduce cannabis. No treatment was provided. Results Our major findings were a) cost and health/psychological problems were the most common prompting cues, and seeing others use and being offered cannabis were the most common inhibiting cues, b) the number of different types of prompting cues prospectively predicted an increase in attempts to change in a dose-related manner, c) more proximal cues appeared to be more strongly related to change, d) requests to stop or reduce, and physical or psychological problems from cannabis, best predicted change attempts, and e) inhibiting cues did not consistently predict the probability of an attempt to change. Conclusion These preliminary results suggest several environmental cues prompt attempts to change cannabis use. Thus, interventions to increase the frequency of these cues, and specifically requests to stop or reduce cannabis use, and reinforcing concerns about health and mental adverse events from cannabis use may increase cannabis reduction or cessation. PMID:26872879
Hurd, Yasmin L; Michaelides, Michael; Miller, Michael L; Jutras-Aswad, Didier
The adolescent brain is a period of dynamic development making it vulnerable to environmental factors such as drug exposure. Of the illicit drugs, cannabis is most used by teenagers since it is perceived by many to be of little harm. This perception has led to a growing number of states approving its legalization and increased accessibility. Most of the debates and ensuing policies regarding cannabis were done without consideration of its impact on one of the most vulnerable population, namely teens, or without consideration of scientific data. We provide an overview of the endocannabinoid system in relation to adolescent cannabis exposure and provide insights regarding factors such as genetics and behavioral traits that confer risk for subsequent addiction. While it is clear that more systematic scientific studies are needed to understand the long-term impact of adolescent cannabis exposure on brain and behavior, the current evidence suggests that it has a far-reaching influence on adult addictive behaviors particularly for certain subsets of vulnerable individuals. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'.
Benschop, Annemieke; Liebregts, Nienke; van der Pol, Peggy; Schaap, Rick; Buisman, Renate; van Laar, Margriet; van den Brink, Wim; de Graaf, Ron; Korf, Dirk J
The Marijuana Motives Measure (MMM) has so far been examined mainly in student populations, often with relatively limited involvement in cannabis use. This study evaluated the factor structure of the MMM in a demographically mixed sample of 600 young adult (18-30 years) frequent (≥ 3 days per week) cannabis users in the Netherlands. Analysis confirmed a five-factor solution, denoting coping, enhancement, social, conformity and expansion motives. Additionally, the original MMM was extended with two items (boredom and habit), which formed a distinct, internally consistent sixth factor labelled routine motives. In a multivariable logistic regression analysis, coping and routine motives showed significant associations with 12-month DSM-IV cannabis dependence. The results suggest general reliability and validity of the MMM in a heterogeneous population of experienced cannabis users.
van Wel, J H P; Kuypers, K P C; Theunissen, E L; Toennes, S W; Spronk, D B; Verkes, R J; Ramaekers, J G
BACKGROUND AND PURPOSE Cannabis is the most popular drug used in the European Union, closely followed by cocaine. Whereas cannabis impairs neurocognitive function in occasional cannabis users, such impairments appear less prominent in heavy users, possibly as a result of tolerance. The present study was designed to assess whether the impairing effects of Δ9-tetrahydrocannabinol (THC) in heavy cannabis users would present in a wide range of neuropsychological functions or selectively affect specific performance domains. We also assessed the acute effects of cocaine on neurocognitive functions of heavy cannabis users. EXPERIMENTAL APPROACH Heavy cannabis users, who had a history of cocaine use (n = 61), participated in a double-blind, placebo-controlled, three-way crossover study. Subjects received single doses of cocaine HCl (300 mg), cannabis (THC μg·kg−1) and placebo, and completed a number of tests measuring impulse control and psychomotor function. KEY RESULTS Single doses of cannabis impaired psychomotor function and increased response errors during impulsivity tasks. Single doses of cocaine improved psychomotor function and decreased response time in impulsivity tasks, but increased errors. CONCLUSIONS AND IMPLICATIONS Heavy cannabis users display impairments in a broad range of neuropsychological domains during THC intoxication. Impairments observed in psychomotor tasks, but not in impulsivity tasks, appeared smaller in magnitude as compared with those previously reported in occasional cannabis users. Heavy cannabis users were sensitive to the stimulating and inhibitory effects of cocaine on psychomotor function and impulsivity respectively. The reduction in proficiency in impulse control may put drug users at increased risk of repeated drug use and addiction. PMID:24106872
Black, Shimrit K.; de Moor, Carl; Kendall, Ashley D.; Shrier, Lydia A.
This study examines the feasibility of recruiting and retaining adolescents and young adults with frequent cannabis use for a 2-week momentary sampling study of cannabis use. Participants responded to random signals on a handheld computer with reports of their use. Participants also initiated reports pre- and post-cannabis use. Participants had…
Jin, Lexie Zhiyan; Rangan, Anna; Mehlsen, Jesper; Andersen, Lars Bo; Larsen, Sofus C.; Heitmann, Berit L.
Cannabis use has been found to stimulate appetite and potentially promote weight gain via activation of the endocannabinoid system. Despite the fact that the onset of cannabis use is typically during adolescence, the association between adolescence cannabis use and long-term change in body weight is generally unknown. This study aims to examine the association between adolescence cannabis use and weight change to midlife, while accounting for the use of other substances. The study applied 20 to 22 years of follow-up data on 712 Danish adolescents aged between 15 and 19 years at baseline. Self-reported height and weight, cannabis, cigarette and alcohol use, socioeconomic status (SES) and physical activity levels were assessed in baseline surveys conducted in 1983 and 1985. The follow-up survey was conducted in 2005. In total 19.1% (n = 136) of adolescents reported having used/using cannabis. Weight gain between adolescence and midlife was not related to cannabis exposure during adolescence in either crude or adjusted models, and associations were not modified by baseline alcohol intake or smoking. However, cannabis use was significantly associated with cigarette smoking (p<0.001) and alcohol intake (p<0.001) and inversely associated with physical activity levels (p = 0.04). In conclusion, this study does not provide evidence of an association between adolescence cannabis use and weight change from adolescence to midlife. PMID:28060830
Kowal, Mikael A; van Steenbergen, Henk; Colzato, Lorenza S; Hazekamp, Arno; van der Wee, Nic J A; Manai, Meriem; Durieux, Jeffrey; Hommel, Bernhard
Cannabis has been suggested to impair the capacity to recognize discrepancies between expected and executed actions. However, there is a lack of conclusive evidence regarding the acute impact of cannabis on the neural correlates of error monitoring. In order to contribute to the available knowledge, we used a randomized, double-blind, between-groups design to investigate the impact of administration of a low (5.5 mg THC) or high (22 mg THC) dose of vaporized cannabis vs. placebo on the amplitudes of the error-related negativity (ERN) and error positivity (Pe) in the context of the Flanker task, in a group of frequent cannabis users (required to use cannabis minimally 4 times a week, for at least 2 years). Subjects in the high dose group (n=18) demonstrated a significantly diminished ERN in comparison to the placebo condition (n=19), whereas a reduced Pe amplitude was observed in both the high and low dose (n=18) conditions, as compared to placebo. The results suggest that a high dose of cannabis may affect the neural correlates of both the conscious (late), as well as the initial automatic processes involved in error monitoring, while a low dose of cannabis might impact only the conscious (late) processing of errors.
Huestis, Marilyn A.; Gustafson, Richard A.; Moolchan, Eric T.; Bames, Allan; Bourland, James A.; Sweeney, Stacy A.; Hayes, Eugene F.; Carpenter, Patrick M.; Smith, Michael L.
Fifty-three head hair specimens were collected from 38 males with a history of cannabis use documented by questionnaire, urinalysis and controlled, double blind administration of Δ9-tetrahydrocannabinol (THC) in an institutional review board approved protocol. The subjects completed a questionnaire indicating daily cannabis use (N = 18) or non-daily use, i.e. 1 to 5 cannabis cigarettes per week, (N = 20). Drug use was also documented by a positive cannabinoid urinalysis, a hair specimen was collected from each subject and they were admitted to a closed research unit. Additional hair specimens were collected following smoking of two 2.7% THC cigarettes (N = 13) or multiple oral doses totaling 116 mg THC (N = 2). Cannabinoid concentrations in all hair specimens were determined by ELISA and GCMSMS. Pre- and post dose detection rates did not differ statistically, therefore, all 53 specimens were considered as one group for further comparisons. Nineteen specimens (36%) had no detectable THC or 11-nor-9-carboxy-THC (THCCOOH) at the GCMSMS limits of quantification (LOQ) of 1.0 and 0.1 pg/mg hair, respectively. Two specimens (3.8%) had measurable THC only, 14 (26%) THCCOOH only, and 18 (34%) both cannabinoids. Detection rates were significantly different (p < 0.05, Fishers' exact test) between daily cannabis users (85%) and non-daily users (52%). There was no difference in detection rates between African American and Caucasian subjects (p > 0.3, Fisher's exact test). For specimens with detectable cannabinoids, concentrations ranged from 3.4 to > 100 pg THC/mg and 0.10 to 7.3 pg THCCOOH/mg hair. THC and THCCOOH concentrations were positively correlated (r = 0.38, p < 0.01, Pearson's product moment correlation). Using an immunoassay cutoff concentration of 5 pg THC equivalents/mg hair, 83% of specimens that screened positive were confirmed by GCMSMS at a cutoff concentration of 0.1 pg THCCOOH/mg hair. PMID:16963215
Huestis, Marilyn A; Gustafson, Richard A; Moolchan, Eric T; Barnes, Allan; Bourland, James A; Sweeney, Stacy A; Hayes, Eugene F; Carpenter, Patrick M; Smith, Michael L
Fifty-three head hair specimens were collected from 38 males with a history of cannabis use documented by questionnaire, urinalysis and controlled, double blind administration of delta9-tetrahydrocannabinol (THC) in an institutional review board approved protocol. The subjects completed a questionnaire indicating daily cannabis use (N=18) or non-daily use, i.e. one to five cannabis cigarettes per week (N=20). Drug use was also documented by a positive cannabinoid urinalysis, a hair specimen was collected from each subject and they were admitted to a closed research unit. Additional hair specimens were collected following smoking of two 2.7% THC cigarettes (N=13) or multiple oral doses totaling 116 mg THC (N=2). Cannabinoid concentrations in all hair specimens were determined by ELISA and GCMSMS. Pre- and post-dose detection rates did not differ statistically, therefore, all 53 specimens were considered as one group for further comparisons. Nineteen specimens (36%) had no detectable THC or 11-nor-9-carboxy-THC (THCCOOH) at the GCMSMS limits of quantification (LOQ) of 1.0 and 0.1 pg/mg hair, respectively. Two specimens (3.8%) had measurable THC only, 14 (26%) THCCOOH only, and 18 (34%) both cannabinoids. Detection rates were significantly different (p<0.05, Fishers' exact test) between daily cannabis users (85%) and non-daily users (52%). There was no difference in detection rates between African-American and Caucasian subjects (p>0.3, Fisher's exact test). For specimens with detectable cannabinoids, concentrations ranged from 3.4 to >100 pg THC/mg and 0.10 to 7.3 pg THCCOOH/mg hair. THC and THCCOOH concentrations were positively correlated (r=0.38, p<0.01, Pearson's product moment correlation). Using an immunoassay cutoff concentration of 5 pg THC equiv./mg hair, 83% of specimens that screened positive were confirmed by GCMSMS at a cutoff concentration of 0.1 pg THCCOOH/mg hair.
Ramaekers, J G; Kauert, G; Theunissen, E L; Toennes, S W; Moeller, M R
Performance impairment during Delta(9)-tetrahydrocannabinol (THC) intoxication has been well described in occasional cannabis users. It is less clear whether tolerance develops to the impairing effects of THC in heavy users of cannabis. The aim of the present study was to assess neurocognitive performance during acute THC intoxication in occasional and heavy users. Twenty-four subjects (12 occasional cannabis users and 12 heavy cannabis users) participated in a double-blind, placebo-controlled, two-way mixed model design. Both groups received single doses of THC placebo and 500 microg/kg THC by smoking. Performance tests were conducted at regular intervals between 0 and 8 h after smoking, and included measures of perceptual motor control (critical tracking task), dual task processing (divided attention task), motor inhibition (stop signal task) and cognition (Tower of London). THC significantly impaired performance of occasional cannabis users on critical tracking, divided attention and the stop signal task. THC did not affect the performance of heavy cannabis users except in the stop signal task, i.e. stop reaction time increased, particularly at high THC concentrations. Group comparisons of overall performance in occasional and heavy users did not reveal any persistent performance differences due to residual THC in heavy users. These data indicate that cannabis use history strongly determines the behavioural response to single doses of THC.
Shollenbarger, Skyler G.; Price, Jenessa; Wieser, Jon; Lisdahl, Krista
Background The heaviest period of cannabis use coincides with ongoing white matter (WM) maturation. Further, cannabis-related changes may be moderated by FAAH genotype (rs324420). We examined the association between cannabis use and FAAH genotype on frontolimbic WM integrity in adolescents and emerging adults. We then tested whether observed WM abnormalities were linked with depressive or apathy symptoms. Methods Participants included 37 cannabis users and 37 healthy controls (33 female; ages 18–25). Multiple regressions examined the independent and interactive effects of variables on WM integrity. Results Regular cannabis users demonstrated reduced WM integrity in the bilateral uncinate fasciculus (UNC) (MD, right: p = .009 and left: p = .009; FA, right: p = .04 and left: p = .03) and forceps minor (fMinor) (MD, p = .03) compared to healthy controls. Marginally reduced WM integrity in the cannabis users was found in the left anterior thalamic radiation (ATR) (FA, p = .08). Cannabis group ∗ FAAH genotype interaction predicted WM integrity in bilateral ATR (FA, right: p = .05 and left: p = .001) and fMinor (FA, p = .02). In cannabis users, poorer WM integrity was correlated with increased symptoms of depression and apathy in bilateral ATR and UNC. Conclusions Consistent with prior findings, cannabis use was associated with reduced frontolimbic WM integrity. WM integrity was also moderated by FAAH genotype, in that cannabis-using FAAH C/C carriers and A carrying controls had reduced WM integrity compared to control C/C carriers. Observed frontolimbic white matter abnormalities were linked with increased depressive and apathy symptoms in the cannabis users. PMID:26106535
Nelemans, Stefanie A; Hale, William W; Raaijmakers, Quinten A W; Branje, Susan J T; van Lier, Pol A C; Meeus, Wim H J
There appear to be contradicting theories and empirical findings on the association between adolescent Social Anxiety Disorder (SAD) symptoms and cannabis use, suggesting potential risk as well as protective pathways. The aim of this six-year longitudinal study was to further examine associations between SAD symptoms and cannabis use over time in adolescents from the general population, specifically focusing on the potential role that adolescents' involvement with their peers may have in these associations. Participants were 497 Dutch adolescents (57 % boys; M age = 13.03 at T1), who completed annual self-report questionnaires for 6 successive years. Cross-lagged panel analysis suggested that adolescent SAD symptoms were associated with less peer involvement 1 year later. Less adolescent peer involvement was in turn associated with lower probabilities of cannabis use as well as lower frequency of cannabis use 1 year later. Most importantly, results suggested significant longitudinal indirect paths from adolescent SAD symptoms to cannabis use via adolescents' peer involvement. Overall, these results provide support for a protective function of SAD symptoms in association with cannabis use in adolescents from the general population. This association is partially explained by less peer involvement (suggesting increased social isolation) for those adolescents with higher levels of SAD symptoms. Future research should aim to gain more insight into the exact nature of the relationship between anxiety and cannabis use in adolescents from the general population, especially regarding potential risk and protective processes that may explain this relationship.
Menghrajani, P.; Klaue, K.; Dubois-Arber, F.; Michaud, P.-A.
Few studies have attempted to investigate the nature of adolescents and adults conceptions and perceptions of cannabis use. Our objectives were to explore adolescent and adult perception of use and misuse of cannabis, and their opinions and beliefs about the current legal context and preventive strategies. We used focus group discussions with four…
Henry, Erika A; Kaye, Jesse T; Bryan, Angela D; Hutchison, Kent E; Ito, Tiffany A
Substance cue reactivity is theorized as having a significant role in addiction processes, promoting compulsive patterns of drug-seeking and drug-taking behavior. However, research extending this phenomenon to cannabis has been limited. To that end, the goal of the current work was to examine the relationship between cannabis cue reactivity and craving in a sample of 353 participants varying in self-reported cannabis use. Participants completed a visual oddball task whereby neutral, exercise, and cannabis cue images were presented, and a neutral auditory oddball task while event-related brain potentials (ERPs) were recorded. Consistent with past research, greater cannabis use was associated with greater reactivity to cannabis images, as reflected in the P300 component of the ERP, but not to neutral auditory oddball cues. The latter indicates the specificity of cue reactivity differences as a function of substance-related cues and not generalized cue reactivity. Additionally, cannabis cue reactivity was significantly related to self-reported cannabis craving as well as problems associated with cannabis use. Implications for cannabis use and addiction more generally are discussed. PMID:24264815
Lile, Joshua A.; Hanlon, Colleen A.; Porrino, Linda J.
Rationale Long-term heavy cannabis users (cannabis users) who are not acutely intoxicated have diminished subconscious neural responsiveness to affective stimuli. Objective This study sought to determine if abnormal processing extends to the conscious evaluation of emotional stimuli. Methods Functional Magnetic Resonance Imaging (fMRI) was used to examine brain activity as cannabis users (N=16) and non-cannabis using controls (N=17) evaluated and categorized standardized International Affective Picture System (IAPS) stimuli. Individual judgments were used to isolate activity during the evaluation of emotional (i.e., emotional evaluation) or neutral (i.e., neutral evaluation) stimuli. Within- and between-group analyses were performed. Results Both groups judged the same stimuli as emotional and had activations in visual, midbrain, and middle cingulate cortices during emotional evaluation, relative to neutral. Within-group analyses also revealed amygdalar and inferior frontal gyrus activations in controls, but not cannabis users, and medial prefrontal cortex (mPFC) deactivations in cannabis users, but not controls, during emotional evaluation, relative to neutral. Between-group comparisons found that mPFC activity during positive and negative evaluation was significantly hypoactive in cannabis users, relative to controls. Conclusions Abnormal neural processing of affective content extends to the level of consciousness in cannabis users. The hypoactive mPFC responses observed resembles the attenuated mPFC responses found during increased non-affective cognitive load in prior research. These findings suggest that abnormal mPFC singling in cannabis users during emotional evaluation might be associated with increased non-affective cognitive load. PMID:26690589
Enzi, Björn; Lissek, Silke; Edel, Marc-Andreas; Tegenthoff, Martin; Nicolas, Volkmar; Scherbaum, Norbert; Juckel, Georg; Roser, Patrik
Alterations in reward and punishment processing have been reported in adults suffering from long-term cannabis use. However, previous findings regarding the chronic effects of cannabis on reward and punishment processing have been inconsistent. In the present study, we used functional magnetic resonance imaging (fMRI) to reveal the neural correlates of reward and punishment processing in long-term cannabis users (n = 15) and in healthy control subjects (n = 15) with no history of drug abuse. For this purpose, we used the well-established Monetary Incentive Delay (MID) task, a reliable experimental paradigm that allows the differentiation between anticipatory and consummatory aspects of reward and punishment processing. Regarding the gain anticipation period, no significant group differences were observed. In the left caudate and the left inferior frontal gyrus, cannabis users were - in contrast to healthy controls - not able to differentiate between the conditions feedback of reward and control. In addition, cannabis users showed stronger activations in the left caudate and the bilateral inferior frontal gyrus following feedback of no punishment as compared to healthy controls. We interpreted these deficits in dorsal striatal functioning as altered stimulus-reward or action-contingent learning in cannabis users. In addition, the enhanced lateral prefrontal activation in cannabis users that is related to non-punishing feedback may reflect a deficit in emotion regulation or cognitive reappraisal in these subjects.
Enzi, Björn; Lissek, Silke; Edel, Marc-Andreas; Tegenthoff, Martin; Nicolas, Volkmar; Scherbaum, Norbert; Juckel, Georg; Roser, Patrik
Alterations in reward and punishment processing have been reported in adults suffering from long-term cannabis use. However, previous findings regarding the chronic effects of cannabis on reward and punishment processing have been inconsistent. In the present study, we used functional magnetic resonance imaging (fMRI) to reveal the neural correlates of reward and punishment processing in long-term cannabis users (n = 15) and in healthy control subjects (n = 15) with no history of drug abuse. For this purpose, we used the well-established Monetary Incentive Delay (MID) task, a reliable experimental paradigm that allows the differentiation between anticipatory and consummatory aspects of reward and punishment processing. Regarding the gain anticipation period, no significant group differences were observed. In the left caudate and the left inferior frontal gyrus, cannabis users were – in contrast to healthy controls – not able to differentiate between the conditions feedback of reward and control. In addition, cannabis users showed stronger activations in the left caudate and the bilateral inferior frontal gyrus following feedback of no punishment as compared to healthy controls. We interpreted these deficits in dorsal striatal functioning as altered stimulus-reward or action-contingent learning in cannabis users. In addition, the enhanced lateral prefrontal activation in cannabis users that is related to non-punishing feedback may reflect a deficit in emotion regulation or cognitive reappraisal in these subjects. PMID:25799565
Buckner, Julia D; Zvolensky, Michael J; Ecker, Anthony H; Jeffries, Emily R
Social anxiety disorder appears to be a risk factor for cannabis-related problems. Although it is presumed that increases in cannabis craving during elevated social anxiety reflect an intent to cope with greater negative affectivity, it is unclear whether increases in physiological arousal during social stress are related to cannabis craving, especially among those with social anxiety disorder. Similarly, no studies have assessed motivational reasons for cannabis use during elevated social stress. Thus, the current study tested whether increases in state social anxiety (measured subjectively and via physiological arousal) were related to greater cannabis craving among 126 current cannabis users (88.9% with cannabis use disorder, 31.7% with social anxiety disorder, 54.0% non-Hispanic Caucasian) randomly assigned to either a social interaction or reading task. As predicted, cannabis users in the social interaction condition reported greater cannabis craving than those in the reading condition. This effect was particularly evident among those with social anxiety disorder. Although physiological arousal did not moderate the relationship between condition and craving, coping motives were the most common reasons cited for wanting to use cannabis and were reported more among those in the social interaction task. These experimental results uniquely add to a growing literature suggesting the importance of elevated state social anxiety (especially among those with social anxiety disorder) in cannabis use vulnerability processes.
Buckner, Julia D; Zvolensky, Michael J; Ecker, Anthony H; Jeffries, Emily R
Social anxiety disorder appears to be a risk factor for cannabis-related problems. Although it is presumed that increases in cannabis craving during elevated social anxiety reflect an intent to cope with greater negative affectivity, it is unclear whether increases in physiological arousal during social stress are related to cannabis craving, especially among those with social anxiety disorder. Similarly, no studies have assessed motivational reasons for cannabis use during elevated social stress. Thus, the current study tested whether increases in state social anxiety (measured subjectively and via physiological arousal) were related to greater cannabis craving among 126 current cannabis users (88.9% with cannabis use disorder, 31.7% with social anxiety disorder, 54.0% non-Hispanic Caucasian) randomly assigned to either a social interaction or reading task. As predicted, cannabis users in the social interaction condition reported greater cannabis craving than those in the reading condition. This effect was particularly evident among those with social anxiety disorder. Although physiological arousal did not moderate the relationship between condition and craving, coping motives were the most common reasons cited for wanting to use cannabis and were reported more among those in the social interaction task. These experimental results uniquely add to a growing literature suggesting the importance of elevated state social anxiety (especially among those with social anxiety disorder) in cannabis use vulnerability processes. PMID:26839322
Scholes-Balog, Kirsty E; Hemphill, Sheryl A; Evans-Whipp, Tracy J; Toumbourou, John W; Patton, George C
This study aimed to identify distinct developmental trajectories (sub-groups of individuals who showed similar longitudinal patterns) of cannabis use among Australian adolescents, and to examine associations between trajectory group membership and measures of social and behavioural adjustment in young adulthood. Participants (n=852, 53% female) were part of the International Youth Development Study. Latent class growth analysis was used to identify distinct trajectories of cannabis use frequency from average ages 12 to 19, across 6 waves of data. Logistic regression analyses and analyses of covariance were used to examine relationships between trajectory group membership and young adult (average age: 21) adjustment, controlling for a range of covariates. Three trajectories were identified: abstainers (62%), early onset users (11%), and late onset occasional users (27%). The early onset users showed a higher frequency of antisocial behaviour, violence, cannabis use, cannabis-related harms, cigarette use, and alcohol harms, compared to the abstinent group in young adulthood. The late onset occasional users reported a higher frequency of cannabis use, cannabis-related harms, illicit drug use, and alcohol harms, compared to the abstinent group in young adulthood. There were no differences between the trajectory groups on measures of employment, school completion, post-secondary education, income, depression/anxiety, or alcohol use problems. In conclusion, early onset of cannabis use, even at relatively low frequency during adolescence, is associated with poorer adjustment in young adulthood. Prevention and intervention efforts to delay or prevent uptake of cannabis use should be particularly focussed on early adolescence prior to age 12.
McCrystal, Patrick; Winning, Kerry
At the beginning of 2004 the UK government downgraded the legal status of cannabis from a Class B to a Class C drug. Following a review of this decision two years later, cannabis remained a Class C substance--which for some contrasted with the potential harmful social and health effects associated with its use, particularly for young people. These…
Fischer, Benedikt; Dawe, Meghan; Mcguire, Fraser; Shuper, Paul A; Jones, Wayne; Rudzinski, Katherine; Rehm, Jurgen
Aims: Assess key cannabis use, risk and outcome characteristics among high-frequency cannabis users within a university student sample in Toronto, Canada. Methods: N = 134 active universities students (ages of 18-28) using cannabis at least three times per week were recruited by mass advertisement, telephone-screened and anonymously assessed by an…
Beck, François; Guignard, Romain; Richard, Jean-Baptiste
Cannabis is by far the most common illicit drug in France. Among 15-64 years, 32.1% have already experienced it and 8.4% declare they have used it at least once during the past twelve months. In Europe, France is one of the countries with the highest prevalence. Males are markedly more often cannabis users than females and this gender gap tends to increase with the level of use. During the last two decades, the part of the population having tried cannabis did not stop increasing, under the influence of a generalization of the cannabis experience among young people. However, cannabis last year prevalence is rather stable since 2000. Cannabis lifetime use is very rare at the beginning of middle school (1.5% in sixth grade at age 11) but increases in the following years (11% of the pupils of the eighth grade, 24% of the pupils of the ninth grade). Cannabis use at a younger age is related to subsequent onset of cannabis related problems. Adolescent and young adults from high socioeconomic status (SES) more often try cannabis than young people from lower SES. However, cannabis regular use is associated with bad school results, truancy and early school leaving, and with a lower SES. Young people from high SES indeed dispose of greater sociocultural resources to master and regulate their consumption and are more often conscious of their interest not to be tipped over in problematic use.
Kumra, Sanjiv; Robinson, Paul; Tambyraja, Rabindra; Jensen, Daniel; Schimunek, Caroline; Houri, Alaa; Reis, Tiffany; Lim, Kelvin
Objective: In early-onset schizophrenia (EOS), the earliest structural brain volumetric abnormalities appear in the parietal cortices. Early exposure to cannabis may represent an environmental risk factor for developing schizophrenia. This study characterized cerebral cortical gray matter structure in adolescents in regions of interest (ROIs) that…
Riba, J; Valle, M; Sampedro, F; Rodríguez-Pujadas, A; Martínez-Horta, S; Kulisevsky, J; Rodríguez-Fornells, A
Previous studies on the neurocognitive impact of cannabis use have found working and declarative memory deficits that tend to normalize with abstinence. An unexplored aspect of cognitive function in chronic cannabis users is the ability to distinguish between veridical and illusory memories, a crucial aspect of reality monitoring that relies on adequate memory function and cognitive control. Using functional magnetic resonance imaging, we show that abstinent cannabis users have an increased susceptibility to false memories, failing to identify lure stimuli as events that never occurred. In addition to impaired performance, cannabis users display reduced activation in areas associated with memory processing within the lateral and medial temporal lobe (MTL), and in parietal and frontal brain regions involved in attention and performance monitoring. Furthermore, cannabis consumption was inversely correlated with MTL activity, suggesting that the drug is especially detrimental to the episodic aspects of memory. These findings indicate that cannabis users have an increased susceptibility to memory distortions even when abstinent and drug-free, suggesting a long-lasting compromise of memory and cognitive control mechanisms involved in reality monitoring.
D'Souza, Deepak Cyril; Ranganathan, Mohini; Braley, Gabriel; Gueorguieva, Ralitza; Zimolo, Zoran; Cooper, Thomas; Perry, Edward; Krystal, John
Cannabis is one of the most widely used illicit substances and there is growing interest in the association between cannabis use and psychosis. Delta-9-Tetrahydrocannabinol (Delta-9-THC) the principal active ingredient of cannabis has been shown to induce psychotomimetic and amnestic effects in healthy individuals. Whether people who frequently use cannabis are either protected from or are tolerant to these effects of Delta-9-THC has not been established. In a 3-day, double-blind, randomized, placebo-controlled study, the dose-related effects of 0, 2.5, and 5 mg intravenous Delta-9-THC were studied in 30 frequent users of cannabis and compared to 22 healthy controls. Delta-9-THC (1) produced transient psychotomimetic effects and perceptual alterations; (2) impaired memory and attention; (3) increased subjective effects of 'high'; (4) produced tachycardia; and (5) increased serum cortisol in both groups. However, relative to controls, frequent users showed blunted responses to the psychotomimetic, perceptual altering, cognitive impairing, anxiogenic, and cortisol increasing effects of Delta-9-THC but not to its euphoric effects. Frequent users also had lower prolactin levels. These data suggest that frequent users of cannabis are either inherently blunted in their response to, and/or develop tolerance to the psychotomimetic, perceptual altering, amnestic, endocrine, and other effects of cannabinoids.
Riba, J; Valle, M; Sampedro, F; Rodríguez-Pujadas, A; Martínez-Horta, S; Kulisevsky, J; Rodríguez-Fornells, A
Previous studies on the neurocognitive impact of cannabis use have found working and declarative memory deficits that tend to normalize with abstinence. An unexplored aspect of cognitive function in chronic cannabis users is the ability to distinguish between veridical and illusory memories, a crucial aspect of reality monitoring that relies on adequate memory function and cognitive control. Using functional magnetic resonance imaging, we show that abstinent cannabis users have an increased susceptibility to false memories, failing to identify lure stimuli as events that never occurred. In addition to impaired performance, cannabis users display reduced activation in areas associated with memory processing within the lateral and medial temporal lobe (MTL), and in parietal and frontal brain regions involved in attention and performance monitoring. Furthermore, cannabis consumption was inversely correlated with MTL activity, suggesting that the drug is especially detrimental to the episodic aspects of memory. These findings indicate that cannabis users have an increased susceptibility to memory distortions even when abstinent and drug-free, suggesting a long-lasting compromise of memory and cognitive control mechanisms involved in reality monitoring. PMID:25824306
Griffith-Lendering, Merel F. H.; Huijbregts, Stephan C. J.; Huizink, Anja C.; Ormel, Hans; Verhulst, Frank C.; Vollebergh, Wilma A. M.; Swaab, Hanna
Social skills (cooperation, assertion, and self-control) were assessed by teachers for a longitudinal cohort of (pre)adolescents, with measurements at average ages 11.1 (baseline) and 16.3 years (follow-up). Prospective associations with participants' self-reported use of cannabis, (age of) onset of cannabis use, and frequency of use at follow-up…
Butters, Jennifer E.
Estimates the direct impact of family stressors on the progression to problem cannabis use among adolescents in Ontario. Results suggest that family stressors have direct and indirect effects increasing the probability of cannabis use outcomes. The implications of these more complex associations between factors believed to influence adolescent…
Nestor, Liam; Hester, Robert; Garavan, Hugh
Despite an increased understanding of the pharmacology and long-term cognitive effects of cannabis in humans, there has been no research to date examining its chronic effects upon reward processing in the brain. Motivational theories regarding long-term drug use posit contrasting predictions with respect to how drug users are likely to process non-drug incentives. The reward deficiency syndrome (RDS) of addiction posits that there are deficits in dopamine (DA) motivational circuitry for non-drug rewards, such that only drugs of abuse are capable of normalizing DA in the ventral striatum (VS). Alternatively, the opponent process theory (OPT) holds that in individuals prone to drug use, there exists some form of mesolimbic hyperactivity, in which there is a bias towards reward-centred behaviour concomitant with impulsivity. The current study examined BOLD responses during reward and loss anticipation and their outcome deliveries in 14 chronic cannabis users and 14 drug-naïve controls during a monetary incentive delay (MID) task. Despite no significant behavioural differences between the two groups, cannabis users had significantly more right VS BOLD activity during reward anticipation. Correlation analyses demonstrated that this right VS BOLD response was significantly correlated with life-time use and reported life-time cannabis joints consumed. No correlations between cannabis abstinence and BOLD responses were observed. We also observed a number of group differences following outcome deliveries, most notably hypoactivity in the left insula cortex in response to loss and loss avoidance outcome notifications in the cannabis group. These results may suggest hypersensitivity during instrumental response anticipation for non-drug rewards and a hyposensitivity to loss outcomes in chronic cannabis users; the implications of which are discussed with respect to the potentially sensitizing effects of cannabis for other rewards. PMID:19631753
Skosnik, Patrick D; Krishnan, Giri P; D'Souza, Deepak C; Hetrick, William P; O'Donnell, Brian F
Previous work in animals and humans has shown that exogenous cannabinoids disrupt time-locked, evoked gamma oscillations (30–80 Hz). However, no studies to date have examined the effect of cannabis on non-time-locked, induced gamma oscillations during more complex Gestalt perception. The current study therefore utilized electroencephalography (EEG) to examine gamma oscillations during coherent motion perception in heavy cannabis users and controls. Chronic cannabis users (n=24; 12 h abstinence before study; positive 11-nor-9-carboxy-delta-9-tetrahydrocannabinol urine levels) and cannabis-naive controls (n=23) were evaluated. Stimuli consisted of random dot kinetograms (RDKs) that subjects passively viewed during three different conditions: coherent motion, incoherent motion, and static. Time × frequency analysis on EEG data was performed using Fourier-based mean trial power (MTP). Transient event-related potentials (ERPs) to stimulus onset (visual N100 and P200 components) were also evaluated. The results showed that the coherent motion condition produced a robust increase in neural activity in the gamma range (induced power from 40 to 59 Hz) as compared with the incoherent motion and static conditions. As predicted, the cannabis group showed significant reductions in induced gamma power in the coherent condition relative to healthy controls. No differences were observed between the groups in the N100 or P200 components, indicating intact primary sensory processing. Finally, cannabis users showed a trend toward increased scores on the Chapman Perceptual Aberration Scale (PAS) that was positively correlated with total years of active cannabis use. These data suggest that cannabis use may interfere with the generation of induced gamma-band neural oscillations that could in part mediate the perceptual-altering effects of exogenous cannabinoids. PMID:24990428
Palmer, Glen A.; Daiss, Doyle D.
A comparison of personality factors on scales of the Minnesota Multiphasic Personality Inventory-Adolescent (MMPI-A) was conducted with a sample of adolescents referred to a residential substance abuse treatment program. A total of sixty adolescents identified with hallucinogen (n = 20), cannabis (n = 20), or methamphetamine (n = 20) as their drug…
Gonzalez, Raul; Schuster, Randi Melissa; Mermelstein, Robin J; Vassileva, Jasmin; Martin, Eileen M; Diviak, Kathleen R
Recent studies suggest that abstinent cannabis users show deficits on neurocognitive laboratory tasks of impulsive behavior. But results are mixed, and less is known on the performance of non-treatment-seeking, young adult cannabis users. Importantly, relationships between performance on measures of impulsive behavior and symptoms of cannabis addiction remain relatively unexplored. We compared young adult current cannabis users (CU, n = 65) and nonusing controls (NU, n = 65) on several laboratory measures of impulsive behavior, as well as on a measure of episodic memory commonly impacted by cannabis use. The CU group performed more poorly than the NU group on the Hopkins Verbal Learning Test-Revised Total Immediate Recall and Delayed Recall. No significant differences were observed on the measures of impulsive behavior (i.e., Iowa Gambling Task, IGT; Go-Stop Task; Monetary Choice Questionnaire; Balloon Analogue Risk Task). We examined relationships between neurocognitive performance and symptoms of cannabis use disorder symptoms (Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition, DSM-IV CUD) among the CU group, which revealed that poorer IGT performance was associated with more symptoms of DSM-IV CUD. Our results show poorer memory performance among young adult cannabis users than among healthy controls, but no differences on measures of impulsive behavior. However, performance on a specific type of impulsive behavior (i.e., poorer decision making) was associated with more cannabis use disorder symptoms. These results provide preliminary evidence to suggest that decision-making deficits may be more strongly associated with problems experienced from cannabis use, rather than solely being a consequence of cannabis use, per se.
Churchwell, John C; Carey, Paul D; Ferrett, Helen L; Stein, Dan J; Yurgelun-Todd, Deborah A
It has been hypothesized that changes in striatal-mediated dopamine modulation during adolescence may increase the risk for initiating substance abuse as a result of its fundamental role in arbitrating reward sensitivity and motivation during learning and decision making. However, substance abuse during adolescence may also significantly modify striatal structure and function and concomitantly alter reward sensitivity and action control while this brain region is undergoing remodeling. In the present investigation, to assess the relationship of methamphetamine (Meth) or Meth and cannabis (CA) abuse to regional striatal morphology, we acquired structural magnetic resonance images, using a 3T Siemens Trio scanner, from three groups of adolescents composed of healthy controls (n = 10), Meth abusers (n = 9) and combined Meth and CA abusers (Meth+CA, n = 8). We also assessed novelty seeking using the novelty seeking subscale of Cloninger's Tridimensional Character Inventory. The results indicate that adolescent Meth+CA abusers have increased regional striatal volume and show intensified novelty seeking in contrast to the controls. The degree of Meth exposure was also positively correlated with regional striatal volume and novelty seeking in both the Meth and Meth+CA users. These preliminary findings support theories that propose a role for the striatum in adolescent substance abuse and further indicate that novelty seeking may be related to the initiation of, or sustained, drug use.
Impey, Danielle; El-Marj, Nicole; Parks, Andrea; Choueiry, Joelle; Fisher, Derek; Knott, Verner J
Chronic cannabis use may interact with factors, such as age of onset of cannabis use, family history, and genetic factors, to elicit schizophrenia (SZ)-like symptoms, including sensory and cognitive deficits. However, evidence of a relationship between cannabis use and cognitive impairment is confounded by concomitant use of tobacco. The objective of this study was to compare tobacco-naïve cannabis users with individuals without a history of tobacco/cannabis use on the auditory mismatch negativity (MMN) event-related potential (ERP), a neural measure of auditory deviance detection which is diminished in SZ. An exploratory arm of the study, conducted within a randomized, double-blind, placebo controlled design, examined the acute effects of nicotine gum (6mg) on MMN in cannabis users. MMN was recorded in response to 5 deviant stimuli within an optimal MMN paradigm in 44 healthy, non-tobacco smoking volunteers aged 18-26. Cannabis users (n=21) started smoking cannabis prior to age 17, at least 1 joint per month. To examine the effects of chronicity, users were grouped into relatively heavy long-term (HLT; n=11) users and light short-term (LST; n=10) users. Impaired deviance detection was shown in cannabis users vs. nonusers as reflected by a smaller MMN to duration deviants. Chronicity of use was also associated with MMN alterations, as HLTs displayed a reduced duration and gap MMN vs. LSTs. Compared with placebo, nicotine treatment enhanced select MMN deviants in cannabis user subgroups. As deficits associated with early and persistent cannabis use are similar to those seen in SZ, these dose-dependant disturbances in early sensory processing with cannabis use may be one cognitive pathway which mediates an increased risk for SZ in vulnerable youth, and be influenced by concurrent cigarette smoking behavior.
Lewis, John; Molnar, Anna; Allsop, David; Copeland, Jan; Fu, Shanlin
Urinary 11-nor-Δ(9)-tetrahydrocannabinol-9-carboxylic acid (Carboxy-THC) concentrations, normalised to creatinine output, have been demonstrated to be a useful tool in the interpretation of the results of a series of urine tests for cannabis. These tests, often termed historical data, can be used to identify potential chronic cannabis users who may present occupational health and safety risks within the workplace. Conversely, the data can also be used to support employee claims of previous regular, rather than recent, cannabis use. This study aimed at examining the mean elimination of Carboxy-THC in 37 chronic users undergoing voluntary abstinence over a 2-week period. Urine specimens were collected prior to the study and after 1 and 2 weeks of abstinence. Carboxy-THC levels in urine were measured by gas chromatography-mass spectrometry (GC-MS) following alkaline hydrolysis, organic solvent extraction and derivatisation to form its pentafluoropropionic derivative. The creatinine-normalised Carboxy-THC concentrations declined rapidly over the 2 weeks of abstinence period and the majority of chronic cannabis users (73%) reduced their urinary Carboxy-THC levels to below the 15-μg/L confirmatory cutoff within that time. The study further highlights the value of historical urinary Carboxy-THC data as a means of identifying potential occupational health and safety risks among chronic cannabis users.
Anticević, Vesna; Britvić, Dolores; Sodić, Lidija
The purpose of this study was to investigate differences in social characteristics (level of education, working and family status, and criminal record) between heroin addicts, cannabis users and a control group. Additional goal was to explore the possibility of discerning subjects of different addiction status (of both gender) based on their scores on Eysenck Personality Questionnaire (EPQ). In comparison to the control group, heroin addicts and cannabis users had lower level of education, were more frequently unemployed and with criminal record, and more often came from dysfunctional families. In cannabis users the frequency of these characteristics was generally lower than in heroin addicts. Proportion of correct classification of subjects in groups of different addiction status based on the EPQ scores was 23.3% for males (higher than by chance alone), and 30% for females.
Pacek, Lauren R; Vandrey, Ryan
Cannabis is the most commonly used illicit substance worldwide, and cannabis use disorders (CUDs) are correspondingly high. Increased demand for treatment and relatively low rates of positive clinical outcomes has led to a large scientific investment in the development of interventions for the treatment of CUD. Much of this research is conducted with cannabis users who are not seeking treatment at the time of study participation, and it is unknown whether these individuals are representative of those who seek treatment. This study contrasted samples of cannabis users participating in screening interviews for treatment and nontreatment research studies. Several differences between groups emerged: Treatment-seekers were more likely to be female (43% vs. 29%), older (33.4 vs. 29.7 years), and have longer cannabis use histories compared with non-treatment-seekers (p = .007). Treatment-seekers were more likely to report experiencing guilt after using cannabis and to feel that cannabis use has been a problem for them. Additionally, treatment-seekers reported a greater mean number of reasons for making a quit attempt, experiencing a greater number of withdrawal symptoms, and employing more coping strategies during prior quit attempts. Despite the aforementioned differences, the 2 groups were similar on several key characteristics, particularly with regards to current levels of cannabis use and related problems.
Dunlop, Joseph; Ketcherside, Ariel; Baine, Jessica; Rhinehardt, Tyler; Kuhn, Brittany; DeWitt, Sam; Alvi, Talha
Abstract Although there is emergent evidence illustrating neural sensitivity to cannabis cues in cannabis users, the specificity of this effect to cannabis cues as opposed to a generalized hyper‐sensitivity to hedonic stimuli has not yet been directly tested. Using fMRI, we presented 53 daily, long‐term cannabis users and 68 non‐using controls visual and tactile cues for cannabis, a natural reward, and, a sensory‐perceptual control object to evaluate brain response to hedonic stimuli in cannabis users. The results showed an interaction between group and reward type such that the users had greater response during cannabis cues relative to natural reward cues (i.e., fruit) in the orbitofrontal cortex, striatum, anterior cingulate gyrus, and ventral tegmental area compared to non‐users (cluster‐threshold z = 2.3, P < 0.05). In the users, there were positive brain‐behavior correlations between neural response to cannabis cues in fronto‐striatal‐temporal regions and subjective craving, marijuana‐related problems, withdrawal symptoms, and levels of THC metabolites (cluster‐threshold z = 2.3, P < 0.05). These findings demonstrate hyper‐responsivity, and, specificity of brain response to cannabis cues in long‐term cannabis users that are above that of response to natural reward cues. These observations are concordant with incentive sensitization models suggesting sensitization of mesocorticolimbic regions and disruption of natural reward processes following drug use. Although the cross‐sectional nature of this study does not provide information on causality, the positive correlations between neural response and indicators of cannabis use (i.e., THC levels) suggest that alterations in the reward system are, in part, related to cannabis use. Hum Brain Mapp 37:3431–3443, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc. PMID:27168331
Thames, April D.; Arbid, Natalie; Sayegh, Philip
Objective With the recent debates over marijuana legalization and increases in use, it is critical to examine its role in cognition. While many studies generally support the adverse acute effects of cannabis on neurocognition, the non-acute effects remain less clear. The current study used a cross-sectional design to examine relationships between recent and past cannabis use on neurocognitive functioning in a non-clinical adult sample. Method One hundred and fifty-eight participants were recruited through fliers distributed around local college campuses and the community. All participants completed the Brief Drug Use History Form, the Structured Clinical Interview for DSM-IV Disorders, and neurocognitive assessment, and underwent urine toxicology screening. Participants consisted of recent users (n = 68), past users (n = 41), and non-users (n = 49). Results Recent users demonstrated significantly (p < .05) worse performance than non-users across cognitive domains of attention/working memory (M = 42.4, SD = 16.1 vs. M = 50.5, SD = 10.2), information processing speed (M = 44.3, SD = 7.3 vs. M = 52.1, SD = 11.0), and executive functioning (M = 43.6, SD = 13.4 vs. M = 48.6, SD = 7.2). There were no statistically significant differences between recent users and past users on neurocognitive performance. Frequency of cannabis use in the last 4 weeks was negatively associated with global neurocognitive performance and all individual cognitive domains. Similarly, amount of daily cannabis use was negatively associated with global neurocognitive performance and individual cognitive domains. Conclusions Our results support the widespread adverse effects of cannabis use on neurocognitive functioning. Although some of these adverse effects appear to attenuate with abstinence, past users' neurocognitive functioning was consistently lower than non-users. PMID:24556155
Maniglio, Roberto; Innamorati, Marco
To provide a comprehensive picture of the whole spectrum of psychosocial factors potentially associated with adolescent cannabis use, bivariate and multivariate analyses were used to assess a variety of social, demographic, psychological, and behavioral correlates of last-month cannabis use and age of first use among 6,838 students. Results showed that only family problems, alcohol and/or other drug use/misuse, deviant behavior, and victimization were independently associated with either recent cannabis use or early onset of cannabis use when multiple, interacting factors were considered. Certain family and behavioral factors might be more important than other psychosocial correlates of adolescent cannabis use.
Albrecht, Daniel S.; Skosnik, Patrick D.; Vollmer, Jennifer M.; Brumbaugh, Margaret S.; Perry, Kevin M.; Mock, Bruce H.; Zheng, Qi-Huang; Federici, Lauren A.; Patton, Elizabeth A.; Herring, Christine M.; Yoder, Karmen K.
BACKGROUND Although the incidence of cannabis abuse/dependence in Americans is rising, the neurobiology of cannabis addiction is not well understood. Imaging studies have demonstrated deficits in striatal D2/D3 receptor availability in several substance-dependent populations. However, this has not been studied in currently-using chronic cannabis users. OBJECTIVE The purpose of this study was to compare striatal D2/D3 receptor availability between currently-using chronic cannabis users and healthy controls. METHODS Eighteen right-handed males age 18–34 were studied. Ten subjects were chronic cannabis users; eight were demographically matched controls. Subjects underwent a [11C] raclopride (RAC) PET scan. Striatal RAC binding potential (BPND) was calculated on a voxel-wise basis. Prior to scanning, urine samples were obtained from cannabis users for quantification of urine Δ-9-tetrahydrocannabinol (THC) and THC metabolites (11-nor-Δ-9-THC-9-carboxylic acid; THC-COOH and 11-hydroxy-THC;OH-THC). Results There were no differences in D2/D3 receptor availability between cannabis users and controls. Voxel-wise analyses revealed that RAC BPND values were negatively associated with both urine levels of cannabis metabolites and self-report of recent cannabis consumption. CONCLUSIONS In this sample, current cannabis use was not associated with deficits in striatal D2/D3 receptor availability. There was an inverse relationship between chronic cannabis use and striatal RAC BPND. Additional studies are needed to identify the neurochemical consequences of chronic cannabis use on the dopamine system. PMID:22909787
Cannabis, Cannabis sativa L., is used to produce a resin that contains high levels of cannabinoids, particularly delta9-tetrahydrocannabinol (THC), which are psychoactive substances. Although cannabis use is illegal in France and in many other countries, it is widely used for its relaxing or euphoric effects, especially by adolescents and young adults. What are the adverse effects of cannabis on health? During consumption? And in the long term? Does cannabis predispose users to the development of psychotic disorders? To answer these questions, we reviewed the available evidence using the standard Prescrire methodology. The long-term adverse effects of cannabis are difficult to evaluate. Since and associated substances, with or without the user's knowledge. Tobacco and alcohol consumption, and particular lifestyles and behaviours are often associated with cannabis use. Some traits predispose individuals to the use of psychoactive substances in general. The effects of cannabis are dosedependent.The most frequently report-ed adverse effects are mental slowness, impaired reaction times, and sometimes accentuation of anxiety. Serious psychological disorders have been reported with high levels of intoxication. The relationship between poor school performance and early, regular, and frequent cannabis use seems to be a vicious circle, in which each sustains the other. Many studies have focused on the long-term effects of cannabis on memory, but their results have been inconclusive. There do not * About fifteen longitudinal cohort studies that examined the influence of cannabis on depressive thoughts or suicidal ideation have yielded conflicting results and are inconclusive. Several longitudinal cohort studies have shown a statistical association between psychotic illness and self-reported cannabis use. However, the results are difficult to interpret due to methodological problems, particularly the unknown reliability of self-reported data. It has not been possible to
Míguez Varela, M Del Carmen; Becoña, Elisardo
This article examined the relationship between cigarette smoking or alcohol consumption and cannabis use and problem gambling among a random and representative sample of 1447 Spanish adolescents (797 males and 650 females with an average of 12.8 years). An ad-hoc questionnaire was used to assess cigarette smoking, alcohol consumption (beer, wine and spirits) and cannabis use. Gambling was assessed with the South Oaks Gambling Screen Revised for Adolescents (SOGS-RA). Results indicated a positive and significant association between cigarette smoking and alcohol consumption and the two aforementioned variables. A larger percentage of cigarette smokers and drinkers was found among those participants who had consumed cannabis before or scored significantly in problem gambling. Additionally, multiple regression analysis confirmed that both cigarette smoking and alcohol consumption (beer and wine) were the most determinant variables for cannabis use and problem gambling.
Cermak, Timmen L
This article begins with a case vignette exemplifying the common clinical problem of heavy marijuana users. The epidemiology and basic science underlying cannabis dependence is outlined, followed by clinical strategies for basing a therapeutic alliance on known research findings and using motivational interviewing to deal with typical patterns of denial.
Georgiades, Katholiki; Boyle, Michael H.
Background: This study examines the longitudinal associations between adolescent tobacco and cannabis use and young adult functioning. Methods: Data for analysis come from the Ontario Child Health Study (OCHS), a prospective study of child health, psychiatric disorder and adolescent substance use in a general population sample that began in 1983,…
Tang, Sephora M.; Ansarian, Aylar; Courtney, Darren B.
Objectives To examine the association between clozapine treatment and frequency of cannabis use in adolescents with co-occurring psychotic and cannabis use disorder in a retrospective cohort chart review. Method We conducted a retrospective cohort chart review of patients diagnosed with a psychotic disorder and concurrent cannabis use disorder admitted to a tertiary care youth inpatient unit from 2010–2012. Longitudinal exposure and outcome data was coded month-by-month. Frequency of cannabis use was measured using a 7-point ordinal scale. Severity of psychosis was measured on a 3-point ordinal scale. Mixed effects regression modeling was used to describe the relationship between exposure and outcome variables. Results Thirteen patients had exposure to clozapine and fourteen had no exposure to clozapine. Cannabis use decreased in patients treated with clozapine, compared to patients treated with other antipsychotics (OR 2.8; 95% CI 0.97–7.9). Compared to no medication, clozapine exposure was associated with significantly less cannabis use (OR 7.1; 95% CI 2.3–22.3). Relative to treatment with other antipsychotics, clozapine exposure was significantly associated with lower severity of psychotic symptoms (OR 3.7; 95% CI 1.2–11.8). Conclusions Clozapine may lead to decreased cannabis use and psychotic symptoms in adolescents with concurrent psychosis and substance use. Clinical trials are warranted. PMID:28331504
Ewing, Sarah W. Feldstein; Mead, Hilary K.; Yezhuvath, Uma; DeWitt, Sam; Hutchison, Kent E.; Filbey, Francesca M.
Given the link between depression, anxiety, and cannabis abuse, a serotonin receptor (rs6311) and transporter polymorphism (rs2020936) were examined as moderators of neural response following a psychosocial treatment for cannabis use disorders (CUDs). While the proposed hypotheses wereunsupported, we found that the rs6311 C allelewas significantly related to brain activation (medial frontal gyrus, precuneus), indicating the role of this serotonin receptor in adolescent treatment response. PMID:23217578
Apostolidis, Thémis; Fieulaine, Nicolas; Soulé, Florence
This study explored the relation of Future time perspective (FTP) to cannabis use and tested the potential mediating role of cannabis perception, with a sample of 276 French adolescents. FTP was assessed using ZTPI subscale, cannabis perception was evaluated from a list of nine items related to drug-oriented perception (DOP), and participants were asked to report both their cannabis use and the level of use. Results showed that FTP acts as a significant predictor of cannabis use, and is significantly linked to DOP. A significant relationship between DOP and cannabis use also appeared. Regression analyses showed that DOP acts as a mediator in the link between FTP and cannabis use. These findings confirm the protective role of FTP in cannabis use and suggest the indirect nature of this role.
Camchong, Jazmin; Lim, Kelvin O; Kumra, Sanjiv
Cannabis is widely perceived as a safe recreational drug and its use is increasing in youth. It is important to understand the implications of cannabis use during childhood and adolescence on brain development. This is the first longitudinal study that compared resting functional connectivity of frontally mediated networks between 43 healthy controls (HCs; 20 females; age M = 16.5 ± 2.7) and 22 treatment-seeking adolescents with cannabis use disorder (CUD; 8 females; age M = 17.6 ± 2.4). Increases in resting functional connectivity between caudal anterior cingulate cortex (ACC) and superior frontal gyrus across time were found in HC, but not in CUD. CUD showed a decrease in functional connectivity between caudal ACC and dorsolateral and orbitofrontal cortices across time. Lower functional connectivity between caudal ACC cortex and orbitofrontal cortex at baseline predicted higher amounts of cannabis use during the following 18 months. Finally, high amounts of cannabis use during the 18-month interval predicted lower intelligence quotient and slower cognitive function measured at follow-up. These data provide compelling longitudinal evidence suggesting that repeated exposure to cannabis during adolescence may have detrimental effects on brain resting functional connectivity, intelligence, and cognitive function.
Bottorff, Joan L; Bissell, Laura J L; Balneaves, Lynda G; Oliffe, John L; Kang, H Bindy K; Capler, N Rielle; Buxton, Jane A; O'Brien, Robin K
The purpose of this qualitative study was to describe how individuals who self-report therapeutic use of cannabis perceive its health effects. Data from 23 individual interviews were transcribed and analyzed. Understandings of gendered roles and identities were used to explore the data and interpret differences in perceptions. Descriptions of the health benefits of cannabis for therapeutic purposes included cannabis as life preserving, a disease therapy, a medicine for the mind, a means for self-management, and a way to manage addiction. Self-management of risks focused on the potential effects of excessive use, smoking-related risks, and purchasing precautions. Although the reports of women and men were similar in many respects, there were important differences in patterns and practices of use that reflected gender influences. Insights from the study provide direction for developing gender-specific information to support decision making and usage for therapeutic users.
Filbey, Francesca M; Aslan, Sina; Lu, Hanzhang; Peng, Shin-Lei
Given the known vascular effects of cannabis, this study examined the neurophysiological factors that may affect studies of brain activity in cannabis users. We conducted a systematic evaluation in 72 h abstinent, chronic cannabis users (N=74) and nonusing controls (N=101) to determine the association between prolonged cannabis use and the following neurophysiological indicators: (1) global and regional resting cerebral blood flow (CBF), (2) oxygen extraction fraction (OEF), and (3) cerebral metabolic rate of oxygen (CMRO2). We found that cannabis users had greater global OEF and CMRO2 compared with nonusers. Regionally, we found higher CBF in the right pallidum/putamen of the cannabis users compared with nonusers. Global resting CBF and regional CBF of right superior frontal cortex correlated positively with creatinine-normalized Δ9-tetrahydrocannabinol (THC) levels. These findings demonstrate residual effects of cannabis use whereby global and regional brain metabolism are altered in those with prolonged cannabis exposure. These neurophysiological alterations should be considered in both research and clinical applications.Neuropsychopharmacology advance online publication, 22 March 2017; doi:10.1038/npp.2017.44.
Beck, Olof; Sandqvist, Sören; Dubbelboer, Ilse; Franck, Johan
Exhaled breath has recently been proposed as a new possible matrix for drugs of abuse testing. A key drug is cannabis, and the present study was aimed at investigating the possibility of detecting tetrahydrocannabinol and tetrahydrocannabinol carboxylic acid in exhaled breath after cannabis smoking. Exhaled breath was sampled from 10 regular cannabis users and 8 controls by directing the exhaled breath by suction through an Empore C(18) disk. The disk was extracted with hexane/ethyl acetate, and the resulting extract was evaporated to dryness and redissolved in 100 μL hexane/ethyl acetate. A 3-μL aliquot was injected onto the LC-MS-MS system and analyzed using positive electrospray ionization and selected reaction monitoring. In samples collected 1-12 h after cannabis smoking, tetrahydrocannabinol was detected in all 10 subjects. The rate of excretion was between 9.0 and 77.3 pg/min. Identification of tetrahydrocannabinol was based on correct retention time relative to tetrahydrocannabinol-d(3) and correct product ion ratio. In three samples, peaks were observed for tetrahydrocannabinol carboxylic acid, but these did not fulfill identification criteria. Neither tetrahydrocannabinol or tetrahydrocannabinol carboxylic acid was detected in the controls. These results confirm older reports that tetrahydrocannabinol is present in exhaled breath following cannabis smoking and extend the detection time from minutes to hours. The results further support the idea that exhaled breath is a promising matrix for drugs-of-abuse testing.
Best, David; Gross, Samantha; Manning, Victoria; Gossop, Michael; Witton, John; Strang, John
The study uses a school-based sample to test the social and familial risk and protective factors relating to cannabis use. Based on a self-completion survey of 2078 14-16-year-olds (mean age of 15 years) attending seven standard state-run secondary schools in south London, an assessment was made of rates and risk factors for cannabis use. Twenty-four per cent of the total sample had ever used cannabis, with 15% having done so in the month prior to assessment. In addition to greater likelihood of illicit drug use, lifetime cannabis users were less likely to spend time regularly with both their mothers and fathers, but more likely to spend free time with friends who smoked, drank alcohol and used illicit drugs, and with friends involved in criminal activities. Among those who had ever used cannabis, frequency of cannabis use was predicted (using linear regression) by two onset factors (earlier initiation of drinking and cannabis use were both linked to more frequent use) and two social factors (more time spent with drug-using friends and less time spent with the mother). Overall, the study showed that early onset, itself predicted by social networks, is linked to more frequent use of cannabis and that this appears to be sustained by less time spent with parents and more with drug-using peers.
French, Leon; Gray, Courtney; Leonard, Gabriel; Perron, Michel; Pike, G. Bruce; Richer, Louis; Séguin, Jean R.; Veillette, Suzanne; Evans, C. John; Artiges, Eric; Banaschewski, Tobias; Bokde, Arun W. L.; Bromberg, Uli; Bruehl, Ruediger; Buchel, Christian; Cattrell, Anna; Conrod, Patricia J.; Flor, Herta; Frouin, Vincent; Gallinat, Jurgen; Garavan, Hugh; Gowland, Penny; Heinz, Andreas; Lemaitre, Herve; Martinot, Jean-Luc; Nees, Frauke; Orfanos, Dimitri Papadopoulos; Pangelinan, Melissa Marie; Poustka, Luise; Rietschel, Marcella; Smolka, Michael N.; Walter, Henrik; Whelan, Robert; Timpson, Nic J.; Schumann, Gunter; Smith, George Davey; Pausova, Zdenka; Paus, Tomáš
IMPORTANCE Cannabis use during adolescence is known to increase the risk for schizophrenia in men. Sex differences in the dynamics of brain maturation during adolescence may be of particular importance with regard to vulnerability of the male brain to cannabis exposure. OBJECTIVE To evaluate whether the association between cannabis use and cortical maturation in adolescents is moderated by a polygenic risk score for schizophrenia. DESIGN, SETTING, AND PARTICIPANTS Observation of 3 population-based samples included initial analysis in 1024 adolescents of both sexes from the Canadian Saguenay Youth Study (SYS) and follow-up in 426 adolescents of both sexes from the IMAGEN Study from 8 European cities and 504 male youth from the Avon Longitudinal Study of Parents and Children (ALSPAC) based in England. A total of 1577 participants (aged 12–21 years; 899 [57.0%] male) had (1) information about cannabis use; (2) imaging studies of the brain; and (3) a polygenic risk score for schizophrenia across 108 genetic loci identified by the Psychiatric Genomics Consortium. Data analysis was performed from March 1 through December 31, 2014. MAIN OUTCOMES AND MEASURES Cortical thickness derived from T1-weighted magnetic resonance images. Linear regression tests were used to assess the relationships between cannabis use, cortical thickness, and risk score. RESULTS Across the 3 samples of 1574 participants, a negative association was observed between cannabis use in early adolescence and cortical thickness in male participants with a high polygenic risk score. This observation was not the case for low-risk male participants or for the low- or high-risk female participants. Thus, in SYS male participants, cannabis use interacted with risk score vis-à-vis cortical thickness (P = .009); higher scores were associated with lower thickness only in males who used cannabis. Similarly, in the IMAGEN male participants, cannabis use interacted with increased risk score vis-à-vis a change in
Christensen, Bruce K.; Streiner, David L.; Roy, Carolyn; Patriciu, Iulia; Zipursky, Robert B.
Rationale Frequent cannabis use is a risk marker for schizophrenia and delusions, but the neurocognitive mechanisms of this relationship remain unclear. Objectives We sought evidence that cannabis users have deficits in processing relationships between meaningful stimuli, similar to abnormalities reported in schizophrenia, and that these deficits are associated with delusion-like ideation. We used the N400 event-related brain potential (ERP) waveform as a neurophysiological probe of activation of concepts in semantic memory. We hypothesized that cannabis users would exhibit larger (more negative) than normal N400 amplitudes in response to stimuli meaningfully related to a preceding prime—reflecting deficient activation of concepts related to the prime. We further hypothesized that the magnitude of this abnormality would correlate with severity of delusion-like ideation. Methods We recorded ERPs in 24 frequent cannabis users and 24 non-using comparison participants who viewed prime words followed by targets which were either words related or unrelated to the prime or pronounceable non-words. The participants’ task was to indicate whether the target was a word. Delusion-like ideation was measured via the Schizotypal Personality Questionnaire. Results Contrary to our hypothesis, cannabis users exhibited smaller than normal N400s to both related and unrelated targets. These abnormalities correlated with delusion-like ideation in cannabis users only. Conclusions The results are consistent with a generalized abnormality of activation within semantic memory neural networks in cannabis users. Further research is needed to investigate whether such an abnormality plays a role in the development of delusion-like ideation in cannabis users. PMID:22782461
Lile, Joshua A; Kelly, Thomas H; Charnigo, Richard J; Stinchcomb, Audra L; Hays, Lon R
Oral Δ(9) -tetrahydrocannabinol (Δ(9) -THC) has been evaluated as a medication for cannabis dependence, but repeated administration of acute oral doses up to 40 mg has not been effective at reducing drug-taking behavior. Larger doses might be necessary to affect cannabis use. The purpose of the present study was therefore to determine the physiological and behavioural effects of oral Δ(9) -THC at acute doses higher than those tested previously. The pharmacokinetic and pharmacodynamic profile of oral Δ(9) -THC, administered in ascending order in 15 mg increments across separate sessions, up to a maximum of 90 mg, was determined in seven cannabis users. Five subjects received all doses and two experienced untoward side effects at lower doses. Δ(9) -THC produced a constellation of effects consistent with previous clinical studies. Low cannabinoid concentrations were associated with significant effects on drug-sensitive measures, although progressively greater levels did not lead to proportionately larger drug effects. Considerable variability in Cmax and tmax was observed. Doses of oral Δ(9) -THC larger than those tested previously can be administered to individuals with a history of cannabis use, although given the pharmacokinetic variability of oral Δ(9) -THC and individual differences in sensitivity, individualized dose adjustment is needed to avoid side effects and maximize therapeutic response.
Since more than 30 years cannabis is the most common illicit drug in Germany and other European countries. According to different Studies conducted in representative community samples, it can be assumed, that every fifth woman and about every third man, aged 18 to 59 years had used cannabis at least once. Epidemiologic studies also show that cannabis use is strongly associated with adolescence and young adulthood, though. Thus, cannabis consumption significantly increases from age 15, while beginning with the age 23 the proportion of cannabis consumers continuously decreases. Following the results of current studies the majority of consumers uses cannabis rather occasional. Nevertheless about 10-15% of the current consumers show patterns of cannabis dependence according to international diagnostic criteria. Although counselling centres note an increasing demand for addiction specific treatment, cannabis users still remain a small group in treatment centre statistics.
Bossong, Matthijs G; Niesink, Raymond J M
Cannabis use during adolescence increases the risk of developing psychotic disorders later in life. However, the neurobiological processes underlying this relationship are unknown. This review reports the results of a literature search comprising various neurobiological disciplines, ultimately converging into a model that might explain the neurobiology of cannabis-induced schizophrenia. The article briefly reviews current insights into brain development during adolescence. In particular, the role of the excitatory neurotransmitter glutamate in experience-dependent maturation of specific cortical circuitries is examined. The review also covers recent hypotheses regarding disturbances in strengthening and pruning of synaptic connections in the prefrontal cortex, and the link with latent psychotic disorders. In the present model, cannabis-induced schizophrenia is considered to be a distortion of normal late postnatal brain maturation. Distortion of glutamatergic transmission during critical periods may disturb prefrontal neurocircuitry in specific brain areas. Our model postulates that adolescent exposure to Δ9-tetrahydrocannabinol (THC), the primary psychoactive substance in cannabis, transiently disturbs physiological control of the endogenous cannabinoid system over glutamate and GABA release. As a result, THC may adversely affect adolescent experience-dependent maturation of neural circuitries within prefrontal cortical areas. Depending on dose, exact time window and duration of exposure, this may ultimately lead to the development of psychosis or schizophrenia. The proposed model provides testable hypotheses which can be addressed in future studies, including animal experiments, reanalysis of existing epidemiological data, and prospective epidemiological studies in which the role of the dose-time-effect relationship should be central.
Turner, Suzanne D.; Spithoff, Sheryl; Kahan, Meldon
Objective To review the clinical features and complications of at-risk cannabis use and cannabis use disorder, and to outline an office-based protocol for screening, identifying, and managing this disorder. Sources of information PubMed was searched for controlled trials, observational studies, and reviews on cannabis use among adolescents and young adults; cannabis-related medical and psychiatric harms; cannabis use disorder and its treatment; and lower-risk cannabis use guidelines. Main message Physicians should ask all patients about cannabis use. They should ask adolescents and young adults and those at highest risk of cannabis-related harms (those with concurrent psychiatric or substance use disorders) more frequently. Physicians should also ask about cannabis use in patients who have problems that could be caused by cannabis, such as mood disorders, psychosis, and respiratory symptoms. In patients who report cannabis use, physicians should inquire about frequency and amount, tolerance and withdrawal symptoms, attempts to reduce use, and cannabis-related harms. Lower-risk cannabis users smoke, inhale, or ingest cannabis occasionally without evidence of school, work, or social dysfunction; those with problematic use often use cannabis daily or almost daily, have difficulty reducing their use, and have impaired school, work, or social functioning. Physicians should offer all patients with problematic use brief advice and counseling, focusing on the health effects of cannabis and setting a goal of abstinence (some higher-risk groups should not use cannabis at all) or reduced use, and they should provide practical strategies to reduce cannabis use. Physicians should incorporate simple motivational interviewing techniques into the counseling sessions. They should refer those patients who are unable to reduce use or who are experiencing harms from cannabis use to specialized care, while ensuring those patients remain connected to primary care. As well, physicians
Cervellione, Kelly; Cottone, John; Ardekani, Babak A.; Kumra, Sanjiv
Background There is growing evidence that adolescence is a key period for neuronal maturation. Despite the high prevalence of marijuana use among adolescents and young adults in the United States and internationally, very little is known about its impact on the developing brain. Based on neuroimaging literature on normal brain developmental during adolescence, we hypothesized that individuals with heavy cannabis use (HCU) would have brain structure abnormalities in similar brain regions that undergo development during late adolescence, particularly the fronto-temporal connection. Method Fourteen young adult males in residential treatment for cannabis dependence and 14 age-matched healthy male control subjects were recruited. Patients had a history of HCU throughout adolescence; 5 had concurrent alcohol abuse. Subjects underwent structural and diffusion tensor magnetic resonance imaging. White matter integrity was compared between subject groups using voxelwise and fiber tractography analysis. Results Voxelwise and tractography analyses revealed that adolescents with HCU had reduced fractional anisotropy, increased radial diffusivity, and increased trace in the homologous areas known to be involved in ongoing development during late adolescence, particularly in the fronto-temporal connection via arcuate fasciculus. Conclusions Our results support the hypothesis that heavy cannabis use during adolescence may affect the trajectory of normal brain maturation. Due to concurrent alcohol consumption in five HCU subjects, conclusions from this study should be considered preliminary, as the DTI findings reported here may be reflective of the combination of alcohol and marijuana use. Further research in larger samples, longitudinal in nature, and controlling for alcohol consumption is needed to better understand the pathophysiology of the effect of cannabis on the developing brain. PMID:19111160
Rubino, T; Parolaro, D
Epidemiological studies suggest that Cannabis use during adolescence confers an increased risk for developing psychotic symptoms later in life. However, despite their interest, the epidemiological data are not conclusive, due to their heterogeneity; thus modeling the adolescent phase in animals is useful for investigating the impact of Cannabis use on deviations of adolescent brain development that might confer a vulnerability to later psychotic disorders. Although scant, preclinical data seem to support the presence of impaired social behaviors, cognitive and sensorimotor gating deficits as well as psychotic-like signs in adult rodents after adolescent cannabinoid exposure, clearly suggesting that this exposure may trigger a complex behavioral phenotype closely resembling a schizophrenia-like disorder. Similar treatments performed at adulthood were not able to produce such phenotype, thus pointing to a vulnerability of the adolescent brain towards cannabinoid exposure. The neurobiological substrate of the adolescent vulnerability is still largely unknown and experimental studies need to elucidate the cellular and molecular mechanism underlying these effects. However, the few data available seem to suggest that heavy adolescent exposure to cannabinoids is able to modify neuronal connectivity in specific brain areas long after the end of the treatment. This is likely due to disruption of maturational events within the endocannabinoid system during adolescence that in turn impact on the correct neuronal refinement peculiar of the adolescent brain, thus leading to altered adult brain functionality and behavior.
Muro I Rodríguez, A
Previous studies analysing personality and cannabis use in adult samples suggest that cannabis users show significant higher levels of impulsivity, sensation seeking and schizotypy. However, there are few studies exploring this relationship in adolescence using psychobiological models of personality. Given the relevance of identifying individual differences that lead adolescents to early cannabis use to prevent future health problems, the present study aimed to explore the relationship between age, sex, personality and early cannabis use using a psychobiological model of personality in a sample of 415 students (51.8% boys) from 12 to 18 years. Chi(2) tests showed significant higher prevalence of cannabis use in boys and in the group aged 15-18 years. Multiple analysis of variance showed significant higher scores in psychoticism, sensation seeking and in all its subscales in cannabis users group, while an interaction with age was found for extraversion and neuroticism: cannabis users scored higher than non-users in the youngest group (12-14 years) but lower in the oldest group in both dimensions. Finally, regression analysis showed that narrower traits of sensation seeking (experience seeking and disinhibition) were the most associated to early cannabis use. Results are discussed in terms of early cannabis users' personality profiles and in terms of the self-medication theory.
Mayet, Aurélie; Legleye, Stéphane; Chau, Nearkasen; Falissard, Bruno
Licit substance use could be an early stage leading on to cannabis use. The aim of the study was to test a hypothetical sequential process leading from socializing to cannabis use so as to evaluate the mediator role of tobacco and alcohol. Data was derived from a French nationwide survey carried out in 2005 involving 29,393 teenagers aged 17. The analysis used structural equation modelling. The sequence tested was: socializing with friends-tobacco/alcohol use-cannabis use-cannabis use disorders (CUD). Tobacco and alcohol consumptions appeared to be similarly influenced by the time spent with friends. However, tobacco mediation explained 57% of the sequence leading to cannabis use and 61% of the sequence leading to CUD, while the role of alcohol was weaker, at around 13%. Our results underline the effect of peer influence, in the course of night-out socializing, on substance use among adolescents, and the importance of tobacco mediation in the process leading to cannabis use and misuse. This suggests that prevention in places frequented by adolescents should primarily target tobacco consumption, which explains the largest part of cannabis use variance. However, processes linking substance uses seem to be more complex, with the existence of reverse pathways from cannabis to licit drugs. Thus, the gateway effects of tobacco and alcohol require further exploration in relation to simultaneous polysubstance use.
Shollenbarger, Skyler G.; Price, Jenessa; Wieser, Jon; Lisdahl, Krista
Background Regions undergoing maturation with CB1 receptors may be at increased risk for cannabis-induced alterations. Here, we examine the relationships between cannabis use and prefrontal (PFC) and inferior parietal gyrification and surface area (SA) in youth. Methods Participants included 33 cannabis users and 35 controls (ages 18–25). Exclusions included co-morbid psychiatric/neurologic disorders and heavy other drug use. Multiple regressions and Pearson r correlations examined the effects of cannabis use on gyrification, SA and cognition. Results Cannabis use was associated with decreased gyrification in: ventral-medial PFC (RH: [FDR corrected p=.02] LH: [FDR corrected p=.02]); medial PFC (RH: [FDR corrected p=.02], LH: [FDR corrected p=.02]); and frontal poles (RH: [FDR corrected p=.02], LH: [FDR corrected p=.02]). No differences were observed in bilateral hemispheres, PFC, dorsolateral, ventrolateral, or inferior parietal ROIs. Cannabis use was associated with marginally decreased SA in left: medial PFC [FDR corrected p=.09], and ventral lateral PFC: [FDR corrected p=.09]. In cannabis users, increased gyrification was associated with improved working-memory performance in right medial (p=.003), ventral-medial (p=.03), and frontal pole ROIs (p=.007). Conclusions Cannabis use was associated with reduced gyrification in PFC regions implicated in self-referential thought and social cognition. Results suggest that these gyrification characteristics may have cognitive implications. PMID:26233614
Stanger, Catherine; Ryan, Stacy R.; Scherer, Emily A.; Norton, Gray E.; Budney, Alan J.
Objective To conduct a randomized test comparing two multicomponent, contingency management interventions, one with and one without a full parent training curriculum, and an individual treatment for adolescent cannabis use disorders. Method 153 adolescents who met DSM-IV criteria for cannabis abuse or dependence were randomized to motivational enhancement therapy/cognitive-behavioral therapy (MET/CBT), MET/CBT+abstinence-based contingency management (CM), or MET/CBT+CM+Parent Training (PT). Results Overall, during treatment, abstinence was greater for youth receiving clinic- and home-based CM without PT compared to those who received individual MET/CBT. There was no additional benefit of the full parent training curriculum on marijuana use, youth externalizing problems, or parenting. Conclusion These results suggest that clinic- plus home-based CM for cannabis use disorders can increase rates of abstinence during treatment over and above an evidence-based treatment (individual MET/CBT), but the addition of a comprehensive parenting training curriculum did not further enhance efficacy. PMID:26004659
Goodwin, Robert S.; Darwin, William D.; Chiang, C. Nora; Shih, Ming; Li, Shou-Hua; Huestis, Marilyn A.
The time course of 11-nor-9-carboxy-Δ9-tetrahydrocannnabinol (THCCOOH) elimination in urine was characterized in 60 cannabis users during 24 h monitored abstinence on a closed research unit for up to 30 days. 6158 individual urine specimens were screened by immunoassay with values ≥50 ng/mL classified as positive. Urine specimens were confirmed for THCCOOH by gas chromatography/mass spectrometry following base hydrolysis and liquid-liquid or solid phase extraction. In 60%, the maximum creatinine normalized concentration occurred in the first urine specimen; in 40%, peaks occurred as long as 2.9 days after admission. Data were divided into three groups, 0 – 50, 51 – 150, and >150 ng/mg, based on the creatinine corrected initial THCCOOH concentration. There were statistically significant correlations between groups and number of days until first negative and last positive urine specimens; mean number of days were 0.6 and 4.3, 3.2 and 9.7, and 4.7 and 15.4 days respectively, for the three groups. These data provide guidelines for interpreting urine cannabinoid test results and suggest appropriate detection windows for differentiating new cannabis use from residual drug excretion. PMID:19007504
The debate about cannabis policy in Australia has revolved around the harms that cannabis causes to users and the community, on the one hand, and the harms that are caused by the prohibition of its use, on the other. This paper assesses evidence on: (1) the harms caused to users and the community by cannabis use (derived from the international scientific literature) and (2) the harms that arise from prohibition (as reflected in Australian research). The most probable harms caused by cannabis use include: an increased risk of motor vehicle accidents; respiratory disease; dependence; adverse effects on adolescent development; and the exacerbation of psychosis. The harms of the current prohibition on cannabis use policy are less tangible but probably include: the creation of a large blackmarket; disrespect for a widely broken law; harms to the reputation of the unlucky few cannabis users who are caught and prosecuted; lack of access to cannabis for medical uses; and an inefficient use of law enforcement resources. Cannabis policy unavoidably involves trade offs between competing values that should be made by the political process. Australian cannabis policy has converged on a solution which continues to prohibit cannabis but reduces the severity of penalties for cannabis use by either removing criminal penalties or diverting first time cannabis offenders into treatment and education.
Domingo-Salvany, Antónia; Barrio Anta, Gregorio; Sánchez Mañez, Amparo; Llorens Aleixandre, Noelia; Brime Beteta, Begoña; Vicente, Julián
The aim of this study was to examine the feasibility of problem cannabis use screening instruments administration within wide school surveys, their psychometric properties, overlaps, and relationships with other variables. Students from 7 Spanish regions, aged 14–18, who attended secondary schools were sampled by two-stage cluster sampling (net sample 14,589). Standardized, anonymous questionnaire including DSM-IV cannabis abuse criteria, Cannabis Abuse Screening Test (CAST), and Severity of Dependence Scale (SDS) was self-completed with paper and pencil in the selected classrooms. Data was analysed using classical psychometric theory, bivariate tests, and multinomial logistic regression analysis. Not responding to instruments' items (10.5–12.3%) was associated with reporting less frequent cannabis use. The instruments overlapped partially, with 16.1% of positives being positive on all three. SDS was more likely to identify younger users with lower frequency of use who thought habitual cannabis use posed a considerable problem. CAST positivity was associated with frequent cannabis use and related problems. It is feasible to use short psychometric scales in wide school surveys, but one must carefully choose the screening instrument, as different instruments identify different groups of users. These may correspond to different types of problematic cannabis use; however, measurement bias seems to play a role too. PMID:25969832
Wenger, Andreas; Berg, Oliver; Beck, Thilo; Stark, Lars; Buehler, Eveline; Haug, Severin
Background After alcohol and tobacco, cannabis is the most widely used psychoactive substance in many countries worldwide. Although approximately one in ten users develops serious problems of dependency, only a minority attend outpatient addiction counseling centers. A Web-based intervention could potentially reach those users who hesitate to approach such treatment centers. Objective To test the efficacy of a Web-based self-help intervention with and without chat counseling—Can Reduce—in reducing the cannabis use of problematic cannabis users as an alternative to outpatient treatment services. Methods Altogether, 436 participants were recruited by various online and offline media for the Web-based trial. A total of 308 of these were eligible for study participation and were randomly allocated in an unblinded manner to either self-help with chat (n=114), self-help without chat (n=101), or a waiting list control group (n=93). The fully automated self-help intervention consisted of eight modules designed to reduce cannabis use, and was based on the principles of motivational interviewing, self-control practices, and methods of cognitive behavioral therapy. Additional individual chat counseling sessions were based on the same therapeutic principles. The sessions were conducted by trained counselors and addressed participants' personal problems. The main outcomes were the frequency (number of days) and quantity of cannabis use (number of standardized joints) per week, as entered into the consumption diary at baseline and at the 3-month follow-up. Secondary outcomes included self-reported symptoms of cannabis use disorder, severity of cannabis dependence, risky alcohol use, and mental health symptoms. Intervention participation and retention were extracted from the user progress data and the consumption diary, respectively. Results Can Reduce participants were older (U=2.296, P=.02) and reported a greater number of cannabis use days at baseline than patients who
In contemporary societies, risk culture and risk profiling lead to the stigmatization of unhealthy behaviours as 'risky'. Risk denial theory refers to a cognitive way to deal with risky behaviours and can be considered as an updated variant of Sykes and Matza's neutralization theory. People neutralize the 'risky' label using specific techniques that must be added to those previously enlisted by Sykes and Matza. This paper introduces and discusses three techniques of risk denial: scapegoating, self-confidence and comparison between risks. As it is usually defined and studied as a 'risky behaviour', cannabis use provides a relevant example to illustrate these types of risk denial, thanks to various ethnographic studies (including Becker's seminal work on marijuana smokers) and quantitative French data from the 1999 European School Survey on Alcohol and Other Drugs (ESPAD). In order to deny the 'risky' label, cannabis users scapegoat 'hard drugs' users, they emphasize their own ability to control their consumption personally, or they compare cannabis and alcohol risks. The paper concludes with suggestions for further analyses of risk denial.
Caspersen, Shannon; Tau, Gregory Z; Ammerman, Seth
This clinical case conference discusses the case of an adolescent presenting with a marijuana use disorder. Information about a real patient is presented to expert clinicians, who respond to the information by sharing their reasoning and recommendations, followed by a summary of the clinical discussion.
Mokrysz, C; Landy, R; Gage, S H; Munafò, M R; Roiser, J P; Curran, H V
There is much debate about the impact of adolescent cannabis use on intellectual and educational outcomes. We investigated associations between adolescent cannabis use and IQ and educational attainment in a sample of 2235 teenagers from the Avon Longitudinal Study of Parents and Children. By the age of 15, 24% reported having tried cannabis at least once. A series of nested linear regressions was employed, adjusted hierarchically by pre-exposure ability and potential confounds (e.g. cigarette and alcohol use, childhood mental-health symptoms and behavioural problems), to test the relationships between cumulative cannabis use and IQ at the age of 15 and educational performance at the age of 16. After full adjustment, those who had used cannabis ⩾ 50 times did not differ from never-users on either IQ or educational performance. Adjusting for group differences in cigarette smoking dramatically attenuated the associations between cannabis use and both outcomes, and further analyses demonstrated robust associations between cigarette use and educational outcomes, even with cannabis users excluded. These findings suggest that adolescent cannabis use is not associated with IQ or educational performance once adjustment is made for potential confounds, in particular adolescent cigarette use. Modest cannabis use in teenagers may have less cognitive impact than epidemiological surveys of older cohorts have previously suggested.
Rentzsch, Johannes; Stadtmann, Ada; Montag, Christiane; Kunte, Hagen; Plöckl, Doris; Hellweg, Rainer; Gallinat, Jürgen; Kronenberg, Golo; Jockers-Scherübl, Maria Christiane
Long-term cannabis use may confer cognitive deficits and increased risk of psychosis. However, the relationship between cannabis use and schizophrenia is complex. In particular, little is known about the effects of chronic cannabis use on the attention-related electric brain response in schizophrenia. We investigated auditory novelty and oddball P300 evoked potentials in a mixed sample of first-episode and chronic schizophrenic patients and healthy controls with (SZCA, n = 20; COCA, n = 20, abstinence ≥28 days) or without (SZ, n = 20; CO, n = 20) chronic cannabis use. Duration of regular cannabis use was 8.3 ± 5.6 (SZCA) and 9.1 ± 7.1 (COCA) years. In general, schizophrenic patients showed reduced P300 amplitudes. Cannabis use was associated with both a reduced early and late left-hemispheric novelty P300. There was a significant 'diagnosis × cannabis' interaction for the left-hemispheric late novelty P300 in that cannabis use was associated with a reduced amplitude in the otherwise healthy but not in the schizophrenic group compared with their relative control groups (corrected p < 0.02; p > 0.9, respectively). The left-hemispheric late novelty P300 in the otherwise healthy cannabis group correlated inversely with amount and duration of cannabis use (r = -0.50, p = 0.024; r = -0.57, p = 0.009, respectively). Our study confirms attentional deficits with chronic cannabis use. However, cannabis use may lead to different cognitive sequelae in patients with schizophrenia and in healthy controls, possibly reflecting preexisting alterations in the endocannabinoid system in schizophrenia.
Chung, Tammy; Martin, Christoper S.
This study examined the latent class structure of Diagnostic and Statistical Manual of Mental Disorders (text rev.; DSM-IV; American Psychiatric Association, 2000) symptoms used to diagnose cannabis, hallucinogen, cocaine, and opiate disorders among 501 adolescents recruited from addictions treatment. Latent class results were compared with the…
Jager, Gerry; Block, Robert I.; Luijten, Maartje; Ramsey, Nick F.
Objective: Early-onset cannabis use has been associated with later use/abuse, mental health problems (psychosis, depression), and abnormal development of cognition and brain function. During adolescence, ongoing neurodevelopmental maturation and experience shape the neural circuitry underlying complex cognitive functions such as memory and…
Titus, Janet C.; Dennis, Michael L.; Diamond, Guy; Godley, Susan H.; Babor, Thomas; Donaldson, Jean; Herrell, James; Tims, Frank; Webb, Charles
The Cannabis Youth Treatment (CYT) study is a multi-site randomized field experiment examining five outpatient treatment protocols for adolescents who abuse or are dependent on marijuana. The purpose of the CYT project is twofold: (a) to test the relative clinical effectiveness and cost-effectiveness of five promising interventions targeted at…
Cuzen, Natalie L; Koopowitz, Sheri-Michelle; Ferrett, Helen L; Stein, Dan J; Yurgelun-Todd, Deborah
Objectives Methamphetamine abuse affects brain structure and function. Although methamphetamine and cannabis are commonly abused together, few studies have investigated the differential neurocognitive consequences of methamphetamine abuse with or without cannabis. Furthermore, the effects of drug use on the developing adolescent brain remain poorly understood. We compared neurocognitive function between adolescents with ‘pure’ methamphetamine abuse, those with comorbid methamphetamine and cannabis abuse, and healthy controls at baseline and follow-up. Methods Individuals residing in the greater Cape Town region, between the ages of 13 and 18 years, were recruited into either Methamphetamine only group (Meth-only; n=10), Methamphetamine and cannabis group (Meth-cann; n=10) or healthy control (n=20) groups using a quasi-experimental design. All participants underwent a comprehensive neurocognitive assessment. Substance-use variables and psychiatric symptom counts were also recorded. A portion of the Meth-only and control participants completed 12-month follow-up assessments. Results While the Meth-cann group demonstrated widespread neurocognitive deficits at baseline, these deficits were restricted to the self-monitoring domain in the Meth-only group at baseline and at follow-up. Conclusions Methamphetamine abuse with cannabis abuse is associated with significantly more neurocognitive impairment than methamphetamine abuse alone, and such deficits may be enduring. PMID:25636791
Moore, Ashlee A; Neale, Michael C; Silberg, Judy L; Verhulst, Brad
Depression is a highly heterogeneous condition, and identifying how symptoms present in various groups may greatly increase our understanding of its etiology. Importantly, Major Depressive Disorder is strongly linked with Substance Use Disorders, which may ameliorate or exacerbate specific depression symptoms. It is therefore quite plausible that depression may present with different symptom profiles depending on an individual's substance use status. Given these observations, it is important to examine the underlying construct of depression in groups of substance users compared to non-users. In this study we use a non-clinical sample to examine the measurement structure of the Beck Depression Inventory (BDI-II) in non-users and frequent-users of various substances. Specifically, measurement invariance was examined across those who do vs. do not use alcohol, nicotine, and cannabis. Results indicate strict factorial invariance across non-users and frequent-users of alcohol and cannabis, and metric invariance across non-users and frequent-users of nicotine. This implies that the factor structure of the BDI-II is similar across all substance use groups.
Hüsler, Gebhard; Plancherel, Bernard; Werlen, Egon
This research has tested a social disintegration model in conjunction with risk and protection factors that have the power to differentiate relative, weighted interactions among variables in different socially disintegrated groups. The model was tested in a cross-sectional sample of 1082 at-risk youth in Switzerland. Structural equation analyses show significant differences between the social disintegration (low, moderate, high) groups and gender, indicating that the model works differently for groups and for gender. For the highly disintegrated adolescents results clearly show that the risk factors (negative mood, peer network, delinquency) are more important than the protective factors (family relations, secure sense of self). Family relations lose all protective value against negative peer influence, but personal variables, such as secure self, gain protective power.
Kim, Dae-Jin; Skosnik, Patrick D.; Cheng, Hu; Pruce, Ben J.; Brumbaugh, Margaret S.; Vollmer, Jennifer M.; Hetrick, William P.; O'Donnell, Brian F.; Sporns, Olaf; Puce, Aina
Abstract Endocannabinoid receptors modulate synaptic plasticity in the brain and may therefore impact cortical connectivity not only during development but also in response to substance abuse in later life. Such alterations may not be evident in volumetric measures utilized in brain imaging, but could affect the local and global organization of brain networks. To test this hypothesis, we used a novel computational approach to estimate network measures of structural brain connectivity derived from diffusion tensor imaging (DTI) and white matter tractography. Twelve adult cannabis (CB) users and 13 healthy subjects were evaluated using a graph theoretic analysis of both global and local brain network properties. Structural brain networks in both CB subjects and controls exhibited robust small-world network attributes in both groups. However, CB subjects showed significantly decreased global network efficiency and significantly increased clustering coefficients (degree to which nodes tend to cluster around individual nodes). CB subjects also exhibited altered patterns of local network organization in the cingulate region. Among all subjects, schizotypal and impulsive personality characteristics correlated with global efficiency but not with the clustering coefficient. Our data indicate that structural brain networks in CB subjects are less efficiently integrated and exhibit altered regional connectivity. These differences in network properties may reflect physiological processes secondary to substance abuse-induced synaptic plasticity, or differences in brain organization that increase vulnerability to substance use. PMID:22432904
Ellgren, Maria; Spano, Sabrina M; Hurd, Yasmin L
Cannabis use is a hypothesized gateway to subsequent abuse of other drugs such as heroin. We currently assessed whether Delta-9-tetrahydrocannabinol (THC) exposure during adolescence modulates opiate reinforcement and opioid neural systems in adulthood. Long-Evan male rats received THC (1.5 mg/kg intraperitoneally (i.p.)) or vehicle every third day during postnatal days (PNDs) 28-49. Heroin self-administration behavior (fixed ratio-1; 3-h sessions) was studied from young adulthood (PND 57) into full adults (PND 102). THC-pretreated rats showed an upward shift throughout the heroin self-administration acquisition (30 microg/kg/infusion) phase, whereas control animals maintained the same pattern once stable intake was obtained. Heightened opiate sensitivity in THC animals was also evidenced by higher heroin consumption during the maintenance phase (30 and 60 microg/kg/infusion) and greater responding for moderate-low heroin doses (dose-response curve: 7.5, 15, 30, 60, and 100 microg/kg/injection). Specific disturbance of the endogenous opioid system was also apparent in the brain of adults with adolescent THC exposure. Striatal preproenkephalin mRNA expression was exclusively increased in the nucleus accumbens (NAc) shell; the relative elevation of preproenkephalin mRNA in the THC rats was maintained even after heroin self-administration. Moreover, mu opioid receptor (muOR) GTP-coupling was potentiated in mesolimbic and nigrostriatal brainstem regions in THC-pretreated animals. muOR function in the NAc shell was specifically correlated to heroin intake. The current findings support the gateway hypothesis demonstrating that adolescence cannabis exposure has an enduring impact on hedonic processing resulting in enhanced opiate intake, possibly as a consequence of alterations in limbic opioid neuronal populations.
Akre, Christina; Michaud, Pierre-Andre; Berchtold, Andre; Suris, Joan-Carles
The purpose of this article is to identify tobacco and cannabis co-consumptions and consumers' perceptions of each substance. A qualitative research including 22 youths (14 males) aged 15-21 years in seven individual interviews and five focus groups. Discussions were recorded, transcribed verbatim and transferred to Atlas.ti software for narrative…
Farmer, Richard F.; Seeley, John R.; Kosty, Derek B.; Gau, Jeff M.; Duncan, Susan C.; Lynskey, Michael T.; Lewinsohn, Peter M.
Risk-related liabilities associated with the development of cannabis use disorders (CUDs) during adolescence and early adulthood are thought to be established well before the emergence of the index episode. In this study, internalizing and externalizing psychopathology from earlier developmental periods were evaluated as risk factors for CUDs during adolescence and early adulthood. Participants (N = 816) completed four diagnostic assessments between the ages 16 and 30, during which current and past CUDs were assessed as well as a full range of psychiatric disorders associated with internalizing and externalizing psychopathology domains. In unadjusted and adjusted time-to-event analyses, externalizing but not internalizing psychopathology from proximal developmental periods predicted subsequent CUD onset. A large proportion of adolescent and early adult cases, however, did not manifest any externalizing or internalizing psychopathology during developmental periods prior to CUD onset. Findings are consistent with the emerging view that externalizing disorders from proximal developmental periods are robust risk factors for CUDs. Although the identification of externalizing liabilities may aid in the identification of individuals at risk for embarking on developmental pathways that culminate in CUDs, such liabilities are an incomplete indication of overall risk. PMID:25799438
Farmer, Richard F; Seeley, John R; Kosty, Derek B; Gau, Jeff M; Duncan, Susan C; Lynskey, Michael T; Lewinsohn, Peter M
Risk-related liabilities associated with the development of cannabis use disorders (CUDs) during adolescence and early adulthood are thought to be established well before the emergence of the index episode. In this study, internalizing and externalizing psychopathology from earlier developmental periods were evaluated as risk factors for CUDs during adolescence and early adulthood. Participants (N = 816) completed 4 diagnostic assessments between the ages 16 and 30, during which current and past CUDs were assessed as well as a full range of psychiatric disorders associated with internalizing and externalizing psychopathology domains. In unadjusted and adjusted time-to-event analyses, externalizing but not internalizing psychopathology from proximal developmental periods predicted subsequent CUD onset. A large proportion of adolescent and early adult cases, however, did not manifest any externalizing or internalizing psychopathology during developmental periods before CUD onset. Findings are consistent with the emerging view that externalizing disorders from proximal developmental periods are robust risk factors for CUDs. Although the identification of externalizing liabilities may aid in the identification of individuals at risk for embarking on developmental pathways that culminate in CUDs, such liabilities are an incomplete indication of overall risk.
Jacobus, Joanna; Squeglia, Lindsay M; Meruelo, Alejandro D; Castro, Norma; Brumback, Ty; Giedd, Jay N; Tapert, Susan F
Studies suggest marijuana impacts gray and white matter neural tissue development, however few prospective studies have determined the relationship between cortical thickness and cannabis use spanning adolescence to young adulthood. This study aimed to understand how heavy marijuana use influences cortical thickness trajectories across adolescence. Subjects were adolescents with heavy marijuana use and concomitant alcohol use (MJ+ALC, n=30) and controls (CON, n=38) with limited substance use histories. Participants underwent magnetic resonance imaging and comprehensive substance use assessment at three independent time points. Repeated measures analysis of covariance was used to look at main effects of group, time, and Group × Time interactions on cortical thickness. MJ+ALC showed thicker cortical estimates across the brain (23 regions), particularly in frontal and parietal lobes (ps<.05). More cumulative marijuana use was associated with increased thickness estimates by 3-year follow-up (ps<.05). Heavy marijuana use during adolescence and into young adulthood may be associated with altered neural tissue development and interference with neuromaturation that can have neurobehavioral consequences. Continued follow-up of adolescent marijuana users will help understand ongoing neural changes that are associated with development of problematic use into adulthood, as well as potential for neural recovery with cessation of use.
Hall, Wayne; Degenhardt, Louisa
For over two decades, cannabis, commonly known as marijuana, has been the most widely used illicit drug by young people in high-income countries, and has recently become popular on a global scale. Epidemiological research during the past 10 years suggests that regular use of cannabis during adolescence and into adulthood can have adverse effects. Epidemiological, clinical, and laboratory studies have established an association between cannabis use and adverse outcomes. We focus on adverse health effects of greatest potential public health interest-that is, those that are most likely to occur and to affect a large number of cannabis users. The most probable adverse effects include a dependence syndrome, increased risk of motor vehicle crashes, impaired respiratory function, cardiovascular disease, and adverse effects of regular use on adolescent psychosocial development and mental health.
Cannabis is the most widely used illicit drug in the world. Although the risk of problematic cannabis use is relatively low, the lifetime prevalence of dependence is greater than for all other illicit drugs. As such, the population burden of problematic cannabis use warrants attention. Many health and psychosocial risks associated with cannabis…
Lee, Dayong; Bergamaschi, Mateus M.; Milman, Garry; Barnes, Allan J.; Queiroz, Regina H.C.; Vandrey, Ryan; Huestis, Marilyn A.
More Americans are dependent on cannabis than any other illicit drug. The main analytes for cannabis testing include the primary psychoactive constituent, Δ9-tetrahydrocannabinol (THC), equipotent 11-hydroxy-THC (11-OH-THC) and inactive 11-nor-9-carboxy-THC (THCCOOH). Eleven adult chronic frequent cannabis smokers resided on a closed research unit with unlimited access to 5.9% THC cannabis cigarettes from 12:00 to 23:00 during two ad libitum smoking phases, followed by a 5-day abstinence period in seven participants. A single cigarette was smoked under controlled topography on the last day of the smoking and abstinence phases. Plasma cannabinoids were quantified by two-dimensional gas chromatography–mass spectrometry. Median plasma maximum concentrations (Cmax) were 28.3 (THC), 3.9 (11-OH-THC) and 47.0 μg/L (THCCOOH) 0.5 h after controlled single cannabis smoking. Median Cmax 0.2–0.5 h after ad libitum smoking was higher for all analytes: 83.5 (THC), 14.2 (11-OH-THC) and 155 μg/L (THCCOOH). All 11 participants' plasma samples were THC and THCCOOH-positive, 58.3% had THC ≥5 μg/L and 79.2% were 11-OH-THC-positive 8.1–14 h after last cannabis smoking. Cannabinoid detection rates in seven participants 106–112 h (4–5 days) after last smoking were 92.9 (THC), 35.7 (11-OH-THC) and 100% (THCCOOH), with limits of quantification of 0.5 μg/L for THC and THCCOOH, and 1.0 μg/L for 11-OH-THC. These data greatly expand prior research findings on cannabinoid excretion profiles in chronic frequent cannabis smokers during ad libitum smoking. Smoking multiple cannabis cigarettes led to higher Cmax and AUC compared with smoking a single cigarette. The chronic frequent cannabis smokers exhibited extended detection windows for plasma cannabinoids, reflecting a large cannabinoid body burden. PMID:26378131
Simons-Morton, Bruce; Pickett, William; Boyce, Will; ter Bogt, Tom F.M.; Vollebergh, Wilma
Background This research examined the prevalence of drinking and cannabis use among adolescents in the United States, Canada, and the Netherlands, countries with substantially different laws and policies relating to these substances. Method Laws regarding drinking and marijuana use were rated for each country. Substance use prevalence data among 10th graders from the Health Behavior in School-Aged Children Survey conducted in each country in 2005–06 were examined. Results Laws regarding alcohol and cannabis were found to be strictest in the United States, somewhat less strict in Canada, and least strict in the Netherlands. On most measures of drinking, rates were lower in the United States than in Canada or the Netherlands. With United States as the referent, relative risks (RR) for monthly drinking were 1.30 (1.11–1.53) for Canadian boys and 1.55 (1.31–1.83) for girls, and 2.0 (1.73–2.31) for Dutch boys and 1.92 (1.62–2.27) for Dutch girls. Drunkenness was also higher among Canadian boys and girls and Dutch boys. However, rates of cannabis use did not differ between the countries, except that Dutch girls were less likely to use cannabis in the past year (RR= .67; 0.46–0.96). Conclusions The lower prevalence of adolescent drinking and drunkenness (except among Dutch girls) in the United States is consistent with the contention that strict drinking policies may limit drinking among 10th graders. However, the finding that marijuana use rates did not differ across countries is not consistent with the contention that prohibition-oriented policies deter use or that liberal marijuana policies are associated with elevated adolescent use. Based on these findings, the case for strict laws and policies is considerably weaker for marijuana than for alcohol. PMID:19303761
Järvinen, Margaretha; Ravn, Signe
This article analyses how young people enrolled in drug addiction treatment in Copenhagen, Denmark, explain their cannabis careers and how they view their possibilities for quitting drug use again. Inspired by Mead and narrative studies of health and illness, the article identifies four different drug use ‘aetiologies’ drawn upon by the interviewees. These cover childhood experiences, self-medication, the influence of friends and cannabis use as a specific lifestyle. A central argument of the article is that these explanations not only concern the past but also point towards the future by assigning the interviewee a more or less agential position in relation to drugs. Further, the drug narratives are viewed as interactional achievements, related to the social context in which they were produced, namely, the institutional setting of the treatment centres. The article is based on 30 qualitative interviews with young people in drug addiction treatment. PMID:25688710
Järvinen, Margaretha; Ravn, Signe
This article analyses how young people enrolled in drug addiction treatment in Copenhagen, Denmark, explain their cannabis careers and how they view their possibilities for quitting drug use again. Inspired by Mead and narrative studies of health and illness, the article identifies four different drug use 'aetiologies' drawn upon by the interviewees. These cover childhood experiences, self-medication, the influence of friends and cannabis use as a specific lifestyle. A central argument of the article is that these explanations not only concern the past but also point towards the future by assigning the interviewee a more or less agential position in relation to drugs. Further, the drug narratives are viewed as interactional achievements, related to the social context in which they were produced, namely, the institutional setting of the treatment centres. The article is based on 30 qualitative interviews with young people in drug addiction treatment.
Cadoni, Cristina; Simola, Nicola; Espa, Elena; Fenu, Sandro; Di Chiara, Gaetano
Adolescent Cannabis exposure has been hypothesized to act as a gateway to opiate abuse. In order to investigate the role of genetic background in cannabinoid-opiate interactions, we studied the effect of Δ(9) -tetrahydrocannabinol (THC) exposure of adolescent Lewis and Fischer 344 rats on the responsiveness of accumbens shell and core dopamine (DA), as monitored by microdialysis, to THC and heroin at adulthood. Heroin reward and reinstatement by heroin priming were studied by conditioned place preference (CPP) and cognitive and emotional functions by object recognition, Y maze and elevated plus maze paradigms. THC stimulated shell DA in Lewis but not in Fischer 344 rats. Adolescent THC exposure potentiated DA stimulant effects of heroin in the shell and core of Lewis and only in the core of Fischer 344 rats. Control Lewis rats developed stronger CPP to heroin and resistance to extinction compared with Fischer 344 strain. In Lewis rats, THC exposure did not affect heroin CPP but potentiated the effect of heroin priming. In Fischer 344 rats, THC exposure increased heroin CPP and made it resistant to extinction. Lewis rats showed seeking reactions during extinction and hedonic reactions in response to heroin priming. Moreover, adolescent THC exposure affected emotional function only in Lewis rats. These observations suggest that long-term effects of Cannabis exposure on heroin addictive liability and emotionality are dependent on individual genetic background.
Goodwin, Robert S; Darwin, William D; Chiang, C Nora; Shih, Ming; Li, Shou-Hua; Huestis, Marilyn A
The time course of 11-nor-9-carboxy-Delta9-tetrahydrocannnabinol (THCCOOH) elimination in urine was characterized in 60 cannabis users during 24 h monitored abstinence on a closed research unit for up to 30 days. Six thousand, one hundred fifty-eight individual urine specimens were screened by immunoassay with values > or = 50 ng/mL classified as positive. Urine specimens were confirmed for THCCOOH by gas chromatography-mass spectrometry following base hydrolysis and liquid-liquid or solid-phase extraction. In 60%, the maximum creatinine normalized concentration occurred in the first urine specimen; in 40%, peaks occurred as long as 2.9 days after admission. Data were divided into three groups, 0-50, 51-150, and > 150 ng/mg, based on the creatinine corrected initial THCCOOH concentration. There were statistically significant correlations between groups and number of days until first negative and last positive urine specimens; mean number of days were 0.6 and 4.3, 3.2 and 9.7, and 4.7 and 15.4 days, respectively, for the three groups. These data provide guidelines for interpreting urine cannabinoid test results and suggest appropriate detection windows for differentiating new cannabis use from residual drug excretion.
Adlaf, Edward M.; Smart, Reginald G.
Examined rates of steroid use among Ontario adolescent students. Findings from 3,892 students revealed that 1.1 percent reported using steroids over past year. Steroid users were significantly more likely to use stimulants, caffeine, and relaxants than were nonsteroid users. Demographically, steroid users were significantly more likely to be male…
Castellanos-Ryan, Natalie; Pingault, Jean-Baptiste; Parent, Sophie; Vitaro, Frank; Tremblay, Richard E; Séguin, Jean R
The main objective of this prospective longitudinal study was to investigate bidirectional associations between adolescent cannabis use (CU) and neurocognitive performance in a community sample of 294 young men from ages 13 to 20 years. The results showed that in early adolescence, and prior to initiation to CU, poor short-term and working memory, but high verbal IQ, were associated with earlier age of onset of CU. In turn, age of CU onset and CU frequency across adolescence were associated with (a) specific neurocognitive decline in verbal IQ and executive function tasks tapping trial and error learning and reward processing by early adulthood and (b) lower rates of high-school graduation. The association between CU onset and change in neurocognitive function, however, was found to be accounted for by CU frequency. Whereas the link between CU frequency across adolescence and change in verbal IQ was explained (mediated) by high school graduation, the link between CU frequency and tasks tapping trial and error learning were independent from high school graduation, concurrent cannabis and other substance use, adolescent alcohol use, and externalizing behaviors. Findings support prevention efforts aimed at delaying onset and reducing frequency of CU.
Meruelo, A D; Castro, N; Cota, C I; Tapert, S F
Sex hormones and white (and grey) matter in the limbic system, cortex and other brain regions undergo changes during adolescence. Some of these changes include ongoing white matter myelination and sexually dimorphic features in grey and white matter. Adolescence is also a period of vulnerability when many are first exposed to alcohol and cannabis, which appear to influence the developing brain. Neuropsychological studies have provided considerable understanding of the effects of alcohol and cannabis on the brain. Advances in neuroimaging have allowed examination of neuroanatomic changes, metabolic and neurotransmitter activity, and neuronal activation during adolescent brain development and substance use. In this review, we examine major differences in brain development between users and non-users, and recent findings on the influence of cannabis and alcohol on the adolescent brain. We also discuss associations that appear to resolve following short-term abstinence, and attentional deficits that appear to persist. These findings can be useful in guiding earlier educational interventions for adolescents, and clarifying the neural sequelae of early alcohol and cannabis use to the general public.
Ramaekers, J. G.; van Wel, J. H.; Spronk, D. B.; Toennes, S. W.; Kuypers, K. P. C.; Theunissen, E. L.; Verkes, R. J.
Cannabis use history as predictor of neurocognitive response to cannabis intoxication remains subject to scientific and policy debates. The present study assessed the influence of cannabis on neurocognition in cannabis users whose cannabis use history ranged from infrequent to daily use. Drug users (N = 122) received acute doses of cannabis (300 μg/kg THC), cocaine HCl (300 mg) and placebo. Cocaine served as active control for demonstrating neurocognitive test sensitivity. Executive function, impulse control, attention, psychomotor function and subjective intoxication were significantly worse after cannabis administration relative to placebo. Cocaine improved psychomotor function and attention, impaired impulse control and increased feelings of intoxication. Acute effects of cannabis and cocaine on neurocognitive performance were similar across cannabis users irrespective of their cannabis use history. Absence of tolerance implies that that frequent cannabis use and intoxication can be expected to interfere with neurocognitive performance in many daily environments such as school, work or traffic. PMID:27225696
Ramaekers, J G; van Wel, J H; Spronk, D B; Toennes, S W; Kuypers, K P C; Theunissen, E L; Verkes, R J
Cannabis use history as predictor of neurocognitive response to cannabis intoxication remains subject to scientific and policy debates. The present study assessed the influence of cannabis on neurocognition in cannabis users whose cannabis use history ranged from infrequent to daily use. Drug users (N = 122) received acute doses of cannabis (300 μg/kg THC), cocaine HCl (300 mg) and placebo. Cocaine served as active control for demonstrating neurocognitive test sensitivity. Executive function, impulse control, attention, psychomotor function and subjective intoxication were significantly worse after cannabis administration relative to placebo. Cocaine improved psychomotor function and attention, impaired impulse control and increased feelings of intoxication. Acute effects of cannabis and cocaine on neurocognitive performance were similar across cannabis users irrespective of their cannabis use history. Absence of tolerance implies that that frequent cannabis use and intoxication can be expected to interfere with neurocognitive performance in many daily environments such as school, work or traffic.
Becker, Mary P; Collins, Paul F; Lim, Kelvin O; Muetzel, R L; Luciana, M
Diffusion tensor imaging (DTI) studies of cannabis users report alterations in brain white matter microstructure, primarily based on cross-sectional research, and etiology of the alterations remains unclear. We report findings from longitudinal voxelwise analyses of DTI data collected at baseline and at a 2-year follow-up on 23 young adult (18-20 years old at baseline) regular cannabis users and 23 age-, sex-, and IQ-matched non-using controls with limited substance use histories. Onset of cannabis use was prior to age 17. Cannabis users displayed reduced longitudinal growth in fractional anisotropy in the central and parietal regions of the right and left superior longitudinal fasciculus, in white matter adjacent to the left superior frontal gyrus, in the left corticospinal tract, and in the right anterior thalamic radiation lateral to the genu of the corpus callosum, along with less longitudinal reduction of radial diffusion in the right central/posterior superior longitudinal fasciculus, corticospinal tract, and posterior cingulum. Greater amounts of cannabis use were correlated with reduced longitudinal growth in FA as was relatively impaired performance on a measure of verbal learning. These findings suggest that continued heavy cannabis use during adolescence and young adulthood alters ongoing development of white matter microstructure, contributing to functional impairment.
Becker, Mary P.; Collins, Paul F.; Lim, Kelvin O.; Muetzel, R.L.; Luciana, M.
Diffusion tensor imaging (DTI) studies of cannabis users report alterations in brain white matter microstructure, primarily based on cross-sectional research, and etiology of the alterations remains unclear. We report findings from longitudinal voxelwise analyses of DTI data collected at baseline and at a 2-year follow-up on 23 young adult (18-20 years old at baseline) regular cannabis users and 23 age-, sex-, and IQ-matched non-using controls with limited substance use histories. Onset of cannabis use was prior to age 17. Cannabis users displayed reduced longitudinal growth in fractional anisotropy in the central and parietal regions of the right and left superior longitudinal fasciculus, in white matter adjacent to the left superior frontal gyrus, in the left corticospinal tract, and in the right anterior thalamic radiation lateral to the genu of the corpus callosum, along with less longitudinal reduction of radial diffusion in the right central/posterior superior longitudinal fasciculus, corticospinal tract, and posterior cingulum. Greater amounts of cannabis use were correlated with reduced longitudinal growth in FA as was relatively impaired performance on a measure of verbal learning. These findings suggest that continued heavy cannabis use during adolescence and young adulthood alters ongoing development of white matter microstructure, contributing to functional impairment. PMID:26602958
Koenders, Laura; Cousijn, Janna; Vingerhoets, Wilhelmina A M; van den Brink, Wim; Wiers, Reinout W; Meijer, Carin J; Machielsen, Marise W J; Veltman, Dick J; Goudriaan, Anneke E; de Haan, Lieuwe
Cannabis is the most frequently used illicit drug worldwide. Cross-sectional neuroimaging studies suggest that chronic cannabis exposure and the development of cannabis use disorders may affect brain morphology. However, cross-sectional studies cannot make a conclusive distinction between cause and consequence and longitudinal neuroimaging studies are lacking. In this prospective study we investigate whether continued cannabis use and higher levels of cannabis exposure in young adults are associated with grey matter reductions. Heavy cannabis users (N = 20, age baseline M = 20.5, SD = 2.1) and non-cannabis using healthy controls (N = 22, age baseline M = 21.6, SD = 2.45) underwent a comprehensive psychological assessment and a T1- structural MRI scan at baseline and 3 years follow-up. Grey matter volumes (orbitofrontal cortex, anterior cingulate cortex, insula, striatum, thalamus, amygdala, hippocampus and cerebellum) were estimated using the software package SPM (VBM-8 module). Continued cannabis use did not have an effect on GM volume change at follow-up. Cross-sectional analyses at baseline and follow-up revealed consistent negative correlations between cannabis related problems and cannabis use (in grams) and regional GM volume of the left hippocampus, amygdala and superior temporal gyrus. These results suggests that small GM volumes in the medial temporal lobe are a risk factor for heavy cannabis use or that the effect of cannabis on GM reductions is limited to adolescence with no further damage of continued use after early adulthood. Long-term prospective studies starting in early adolescence are needed to reach final conclusions.
de Looze, Margaretha; van den Eijnden, Regina; Verdurmen, Jacqueline; Vermeulen-Smit, Evelien; Schulten, Ingrid; Vollebergh, Wilma; ter Bogt, Tom
Previous research has provided considerable support for idea that increased parental support and control are strong determinants of lower prevalence levels of adolescent risk behavior. Much less is known on the association between specific parenting practices, such as concrete rules with respect to smoking and drinking and adolescent risk behavior. The present paper examined whether such concrete parental rules (1) have an effect on the targeted behaviors and (2) predict other, frequently co-occurring, risk behaviors (i.e., cannabis use and early sexual intercourse). These hypotheses were tested in a nationally representative sample of 12- to 16-year-old adolescents in the Netherlands. We found that both types of rules were associated with a lower prevalence of the targeted behaviors (i.e., smoking and drinking). In addition, independent of adolescent smoking and drinking behaviors, parental rules on smoking predicted a lower prevalence of cannabis use and early sexual intercourse, and parental rules on alcohol use also predicted a lower prevalence of early sexual intercourse. This study showed that concrete parental rule setting is more strongly related to lower levels of risk behaviors in adolescents compared to the more general parenting practices (i.e., support and control). Additionally, the effects of such rules do not only apply to the targeted behavior but extend to related behaviors as well. These findings are relevant to the public health domain and suggest that a single intervention program that addresses a limited number of concrete parenting practices, in combination with traditional support and control practices, may be effective in reducing risk behaviors in adolescence.
Ehlers, Cindy L.; Gizer, Ian R.; Vieten, Cassandra; Gilder, David A.; Stouffer, Gina M.; Lau, Philip; Wilhelmsen, Kirk C.
Cannabis is the most widely used illicit drug in the United States, yet the role of genetics in individual symptoms associated with cannabis use disorders has not been evaluated. The purpose of the present set of analyses was to describe the symptomatology and estimate the heritability of DSM-IV criteria/symptoms of cannabis dependence in a large sample of families. Participants were 2524 adults, participating in the University of California San Francisco (UCSF) Family Study of alcoholism. Seventy percent of the sample had ever used cannabis and 13.9% met DSM-IV criteria for cannabis dependence. Younger age at first cannabis use was found to be significantly associated with a shortened survival to becoming cannabis dependent. Although a greater percentage of men met criteria for cannabis dependence, women were found to demonstrate “telescoping” as indexed by a shorter survival time from initial use to dependence as compared to men. A cannabis withdrawal syndrome was identified in users, the primary symptoms of which were nervousness, appetite change, and sleep disturbance. Cannabis use (h2 = 0.31) and dependence (h2 = 0.20), age at first use, individual DSM-IV criteria for dependence, and cannabis-use associated symptoms of depression, trouble concentrating and paranoia were all found to be heritable. These findings suggest that within this population that cannabis use and dependence, as well as individual cannabis dependence symptoms have a significant heritable component, that cannabis dependence is more likely to occur when use begins during adolescence, and that the cannabis dependence syndrome includes a number of heritable untoward psychiatric side effects including withdrawal. PMID:19818563
Cheng, H; Skosnik, PD; Pruce, BJ; Brumbaugh, MS; Vollmer, JM; Fridberg, DJ; O’Donnell, BF; Hetrick, WP; Newman, SD
Chronic cannabis use can cause cognitive, perceptual and personality alterations, which are believed to be associated with regional brain changes and possible changes in connectivity between functional regions. This study aims to identify the changes from resting state functional magnetic resonance imaging scans. A two-level multi-voxel pattern analysis was proposed to classify male cannabis users from normal controls. The first level analysis works on a voxel basis and identifies clusters for the input of a second level analysis, which works on the functional connectivity between these regions. We found distinct clusters for male cannabis users in the middle frontal gyrus, precentral gyrus, superior frontal gyrus, posterior cingulate cortex, cerebellum and some other regions. Based on the functional connectivity of these clusters, a high overall accuracy rate of 84–88% in classification accuracy was achieved. High correlations were also found between the overall classification accuracy and Barrett Barrett Impulsiveness Scale factor scores of attention and motor. Our result suggests regional differences in the brains of male cannabis users that span from the cerebellum to the prefrontal cortex, which are associated with differences in functional connectivity. PMID:25237118
Wilcox, Holly C; Storr, Carla L; Benoit, Mike Z; Anthony, James C
Working knowledge or vocabulary of drug slang, as a manifestation of learned behavior, might help predict or explain risk of starting to use cannabis in early adolescence. To study this issue, an epidemiologic sample of 1,255 11- to 12-year-olds was assessed for knowledge of cannabis slang terms in 1992, with follow-up in 1993 and 1994. The basic design is that of a prospective and longitudinal study, with recruitment of an epidemiologic sample of children as they entered primary school in a single metropolitan area, also with baseline assessments and randomization to intervention conditions, and subsequent multiple waves of follow-up assessment. Youths assessed in 1992 and who were familiar with terms such as blunts, Mary Jane, roach, and herb were more likely to start using cannabis within the subsequent two years of the follow-up interval, as compared to other youths (estimated relative risk, RR=11.0; 95% CI 3.6-33.7; P<.001). A youth's working vocabulary may signal important variations in health- and disease-related behavior, such as illegal drug use.
Burnett, Kent F.; Kleiman, Mark E.
Used Millon Adolescent Personality Inventory and Profile of Mood States to assess psychological characteristics in 72 adolescent males: 24 adolescent athletes who reported steroid use, 24 athletes with no steroid use, and 24 nonathletes. Although some personality variables differentiated between athletes and nonathletes, no personality variables…
Schiffman, Jason; Nakamura, Brad; Earleywine, Mitchell; LaBrie, Joseph
The current investigation uses a large non-clinical sample of undergraduate college students (N=189) to investigate schizotypal traits among cannabis and non-cannabis users, as well as the temporal order of the onset of these traits and cannabis use. Findings suggest that regular cannabis users are significantly more prone to cognitive and perceptual distortions as well as disorganization, but not interpersonal deficits, than non-regular users and those who have never used. Additionally, the onset of schizotypal symptoms generally precedes the onset of cannabis use. The findings do not support a causal link between cannabis use and schizotypal traits.
Dennis, Michael; Babor, Thomas F; Roebuck, M Christopher; Donaldson, Jean
During the late 1960s, cannabis emerged from relative obscurity to become the most common illicit drug used in the United States, and has remained so ever since. From an epidemiological perspective, three major waves of successively younger new users can be identified during the past 40 years. Contrary to popular opinion, cannabis use can be problematic for many people (particularly adolescents). Moreover, the drug has become increasingly more potent. Cannabis is currently one of the leading substances reported in arrests, emergency room admissions, autopsies and treatment admissions. Like alcohol and tobacco, the need for effective approaches to treating cannabis use disorders transcends debates about whether it should be legal. Moreover, the costs to society are continuing to mount from past neglect of this continuing public health problem. This paper provides background on the need to develop effective models for treating cannabis use disorders.
Cannabis is not a harmless drug. The potential dangers of cannabis are briefly reviewed in this report. The above-mentioned observations on cannabis users should be kept in mind and carefully examined by all physicians. One could expect that as more potent cannabis preparations become available, some of the toxic manifestations which now seem rare might become more frequent. Some of the remarks about the dangers of cannabis may not be proved in future studies, and they may represent only our anxiety. However, prior to the elimination of these fears, no steps should be taken toward the legalizing of marijuana. At present there is no scientific evidence that cannabis is less harmful than either tobacco or alcohol. The opposite may be true. The analogy can be drawn between opium and cannabis. The permissive attitude toward the use of opium can easily lead to the use of morphine and other opiates. If we legalize the use of marijuana, we cannot prevent the use of more dangerous derivatives of cannabis; namely, hashish, cannabis oil and THC, itself. In my opinion, in the light of our present knowledge, legalizing of marijuana could be hazardous both for the individual and for society.
Copeland, Jan; Pokorski, Izabella
Cannabis is the most widely used and variably regulated drug in the world, with increasing trends of use being reported in the US, Australia, Asia, and Africa. Evidence has shown a decrease in the age of commencement of cannabis use in some developed countries and a prolongation of risk of initiation to cannabis use beyond adolescence among more recent users. Cannabis use is associated with numerous health risks and long-term morbidity, as well as risk of developing cannabis-use disorders. Cannabis users infrequently seek professional treatment, and normally do so after a decade of use. Cannabis-use disorders are currently treated using a selection of psychosocial interventions. Severity of withdrawal is a factor that increases the risk of relapse, and is the target of pharmacotherapy studies. Currently, there is no approved pharmacotherapy for cannabis-use disorders. A number of approaches have been examined, and trials are continuing to find a safe and effective medication with little abuse liability. PMID:27217809
The acute side effects caused by cannabis use are mainly related to psyche and cognition, and to circulation. Euphoria, anxiety, changes in sensory perception, impairment of memory and psychomotor performance are common effects after a dose is taken that exceeds an individually variable threshold. Cannabis consumption may increase heart rate and change blood pressure, which may have serious consequences in people with heart disease. Effects of chronic use may be induction of psychosis and development of dependency to the drug. Effects on cognitive abilities seem to be reversible after abstinence, except possibly in very heavy users. Cannabis exposure in utero may have negative consequences on brain development with subtle impairment of cognitive abilities in later life. Consequences of cannabis smoking may be similar to those of tobacco smoking and should be avoided. Use by young people has more detrimental effects than use by adults. There appear to be promising therapeutic uses of cannabis for a range of indications. Use of moderate doses in a therapeutic context is usually not associated with severe side effects. Current prohibition on cannabis use may also have harmful side effects for the individual and the society, while having little influence on prevalence of use. Harm is greatest for seriously ill people who may benefit from a treatment with cannabis. This makes it difficult to justify criminal penalties against patients.
MacDonald, Kai; Pappas, Katherine
In this review, we provide a historical perspective on marijuana, and survey contemporary research investigating its potential negative effects on the brain. We discuss the evidence regarding cannabis dependence, driving under the influence of cannabis, underachievement, inducing (or worsening) certain psychiatric conditions, and the potential for progression to use of more dangerous drugs-summarized by the acronym DDUMB, a cognitive tool that may help healthcare providers in their risk/benefit discussions with patients who use cannabis. We also review and discuss the impact of marijuana use on target populations, including adolescents (who are at increased risk of harm); heavy users; and people suffering from-or at high risk of- mental illness. While cannabis presents certain subjective, healthrelated, and pecuniary benefits to users, growers, and other entities, it is also associated with several brainbased risks. Understanding these risks aids clinicians and their patients in making informed and balanced decisions regarding the initiation or continuance of marijuana use.
Medina, Krista Lisdahl; Nagel, Bonnie J.; Tapert, Susan F.
Background Functional neuroimaging data from adults have, in general, found frontocerebellar dysfunction associated with acute and chronic marijuana (MJ) use (Loeber & Yurgelun-Todd, 1999). One structural neuroimaging study found reduced cerebellar vermis volume in young adult MJ users with a history of heavy polysubstance use (Aasly et al., 1993). The goal of this study was to characterize cerebellar volume in adolescent chronic MJ users following one month of monitored abstinence. Method Participants were MJ users (n=16) and controls (n=16) aged 16-18 years. Extensive exclusionary criteria included history of psychiatric or neurologic disorders. Drug use history, neuropsychological data, and structural brain scans were collected after 28 days of monitored abstinence. Trained research staff defined cerebellar volumes (including three cerebellar vermis lobes and both cerebellar hemispheres) on high-resolution T1-weighted magnetic resonance images. Results Adolescent MJ users demonstrated significantly larger inferior posterior (lobules VIII-X) vermis volume (p<.009) than controls, above and beyond effects of lifetime alcohol and other drug use, gender, and intracranial volume. Larger vermis volumes were associated with poorer executive functioning (p’s<.05). Conclusions Following one month of abstinence, adolescent MJ users had significantly larger posterior cerebellar vermis volumes than non-using controls. These greater volumes are suggested to be pathological based on linkage to poorer executive functioning. Longitudinal studies are needed to examine typical cerebellar development during adolescence and the influence of marijuana use. PMID:20413277
Lopez-Larson, Melissa P.; Bogorodzki, Piotr; Rogowska, Jadwiga; McGlade, Erin; King, Jace B.; Terry, Janine; Yurgelun-Todd, Deborah
Introduction There are limited data regarding the impact of marijuana (MJ) on cortical development during adolescence. Adolescence is a period of substantial brain maturation and cortical thickness abnormalities may be indicative of disruptions of normal cortical development. This investigation applied cortical-surface based techniques to compare cortical thickness measures in MJ using adolescents compared to non-using controls. Methods Eighteen adolescents with heavy MJ use and 18 non-using controls similar in age received MRI scans using a 3T Siemens scanner. Cortical reconstruction and volumetric segmentation was performed with FreeSurfer. Group differences in cortical thickness were assessed using statistical difference maps covarying for age and gender. Results Compared to non-users, MJ users had decreased cortical thickness in right caudal middle frontal, bilateral insula and bilateral superior frontal corticies. Marijuana users had increased cortical thickness in the bilateral lingual, right superior temporal, right inferior parietal and left paracentral regions. In the MJ users, negative correlations were found between frontal and lingual regions for urinary cannabinoid levels and between age of onset of use and the right superior frontal gyrus. Conclusion This is one of the first studies to evaluate cortical thickness in a group of adolescents with heavy MJ use compared to non-users. Our findings are consistent with prior studies that documented abnormalities in prefrontal and insular regions. Our results suggest that age of regular use may be associated with altered prefrontal cortical gray matter development in adolescents. Furthermore, reduced insular cortical thickness may be a biological marker for increased risk of substance dependence. PMID:21310189
Background Research regarding socio-economic differences in alcohol and drug use in adolescence yields mixed results. This study hypothesizes that (1) when using education type as a proxy of one's social status, clear differences will exist between students from different types of education, regardless of students' familial socio-economic background; (2) and that the effects of education type differ according to their cultural background. Methods Data from the Brussels youth monitor were used, a school survey administered among 1,488 adolescents from the 3rd to 6th year of Flemish secondary education. Data were analyzed using multilevel logistic regression models. Results Controlling for their familial background, the results show that native students in lower educational tracks use alcohol and cannabis more often than students in upper educational tracks. Such a relationship was not found for students from another ethnic background. Conclusion Results from this study indicate that research into health risks should take into account both adolescents' familial background and individual social position as different components of youngsters' socio-economic background. PMID:22433291
Park, Subin; Song, Hokwang
Drug abuse has been widely linked to suicide risk. We examined the factors that affect adolescent drug users' suicide attempts in South Korea. This study analyzed the data of 311 adolescents who had used drugs such as inhalants, psychotropic drugs, and marijuana (195 males and 116 females). Among 311 subjects, 109 (35.0%) had attempted suicide during the last 12 months. After adjusting for other variables, depressive mood (OR=19.79) and poly-drug use (OR=2.79), and low/middle levels of academic achievement compared with a high level (OR=3.72 and 4.38) were independently associated with increased odds of a suicide attempt, while better perceived health (OR=0.32) was independently associated with reduced odds of a suicide attempt. For adolescent drug users, preventive work should be directed toward the active treatment of drug use, depression, and physical health and reinforcing proper coping strategies for academic and other stress.
Hall, Wayne; Degenhardt, Louisa
This paper summarizes the most probable of the adverse health effects of regular cannabis use sustained over years, as indicated by epidemiological studies that have established an association between cannabis use and adverse outcomes; ruled out reverse causation; and controlled for plausible alternative explanations. We have also focused on adverse outcomes for which there is good evidence of biological plausibility. The focus is on those adverse health effects of greatest potential public health significance--those that are most likely to occur and to affect a substantial proportion of regular cannabis users. These most probable adverse effects of regular use include a dependence syndrome, impaired respiratory function, cardiovascular disease, adverse effects on adolescent psychosocial development and mental health, and residual cognitive impairment.
Williams, Jenny; van Ours, Jan C; Grossman, Michael
In this paper, we investigate the relationship between cannabis use and attitudes to legalizing the use of cannabis. Predictions from theory provide a means of learning about the roles of information, self interest and regret in explaining differences in attitudes to legalization between those who currently use, those who have used in the past and those who have never used. Our empirical investigation suggests that users have a greater awareness of cannabis not being as harmful as abstainers think it is. This may explain why individuals are more inclined to be in favor of legalizing cannabis once they have used it themselves. Copyright © 2016 John Wiley & Sons, Ltd.
Soyka, M; Preuss, U; Hoch, E
Use and misuse of cannabis and marihuana are frequent. About 5% of the adult population are current users but only 1.2% are dependent. The medical use of cannabis is controversial but there is some evidence for improvement of chronic pain and spasticity. The somatic toxicity of cannabis is well proven but limited and psychiatric disorders induced by cannabis are of more relevance, e.g. cognitive disorders, amotivational syndrome, psychoses and delusional disorders as well as physical and psychological dependence. The withdrawal symptoms are usually mild and do not require pharmacological interventions. To date there is no established pharmacotherapy for relapse prevention. Psychosocial interventions include psychoeducation, behavioral therapy and motivational enhancement. The CANDIS protocol is the best established German intervention among abstinence-oriented therapies.
The developing brain is susceptible to the effects of exogenous cannabinoids both during the perinatal period through maternal cannabis use and in young adolescent users. Emerging data from human and animal perinatal exposure studies demonstrate a subtle rather than gross effect of cannabis upon later functioning including; specific cognitive deficits especially in visuospatial function; impulsivity, inattention and hyperactivity; depressive symptoms; and substance use disorders. From animal studies motor control systems, neuroendocrine function and nociception may additionally be affected. Fetal studies indicate that these outcomes may be through cannabinoid mediated influences on the ontogeny of, especially dopamine and opioid, neurotransmitter systems. The effect of cannabinoids in the adolescent suggest long-term deleterious outcomes in cognition, depressive symptoms, schizophrenia and substance use disorders. Much of these data support a neurodevelopmental effect, however, predisposing genetic and/or environmental factors cannot be excluded from human studies. Gender specific differences have been observed in both human and animal studies implying sex hormone and related factors may interact with cannabinoids in neurodevelopment. Further understanding how cannabinoids influence neurodevelopment will inform public debate about the health effects of cannabis but also open avenues in discerning how modulation of the endocannabinoid system may assist in the development of therapeutic tools for a variety of neuropsychiatric disorders.
Williams, James; Hagger-Johnson, Gareth
Objectives Our aim was to determine the association between childhood academic ability and the onset and persistence of tobacco, alcohol and cannabis use across adolescence in a representative sample of English schools pupils. Previous research has produced conflicting findings. Design Data from 7 years of the Longitudinal Study of Young People in England (LSYPE), 2004–2010 (age 13/14–19/20). Setting Self-completion questionnaires during home visits, face-to-face interviews and web-based questionnaires. Participants Data from 6059 participants (3093 females) with information on academic ability around age 11 and health behaviours from age 13/14 to 16/17 (early adolescence) and from age 18/19 to 19/20 (late adolescence). Outcome measures Regularity of cigarette smoking, alcohol drinking and cannabis use from early to late adolescence. Results In multinomial logistic regression models adjusting for a range of covariates, the high (vs low) academic ability reduced the risk of persistent cigarette smoking (RR=0.62; CI 95% 0.48 to 0.81) in early adolescence. High (vs low) academic ability increased the risk of occasional (RR=1.25; CI 95% 1.04 to 1.51) and persistent (RR=1.83; CI 95% 1.50 to 2.23) regular alcohol drinking in early adolescence and persistent (RR=2.28; CI 95% 1.84 to 2.82) but not occasional regular alcohol drinking in late adolescence. High academic ability was also positively associated with occasional (RR=1.83; CI 95% 1.50 to 2.23) and persistent (RR=1.83; CI 95% 1.50 to 2.23) cannabis use in late adolescence. Conclusions In a sample of over 6000 young people in England, high childhood academic at age 11 is associated with a reduced risk of cigarette smoking but an increased risk of drinking alcohol regularly and cannabis use. These associations persist into early adulthood, providing evidence against the hypothesis that high academic ability is associated with temporary ‘experimentation’ with substance use. PMID:28228447
Williams, Melinda; Jones, Sandra C.; Caputi, Peter; Iverson, Don
Objective: To determine differences in sun-protection behaviours, and incidence of sunburn, between Australian adolescent female fake tan users and non-users. Design: Cross sectional survey. Method: 398 adolescent females aged 12 to 18 years participated in a survey at public venues, schools, and online. The main outcome measures were…
Buckner, Julia D.; Ecker, Anthony H.; Dean, Kimberlye E.
Background and Objectives Individuals with elevated social anxiety are seven times more likely to meet criteria for cannabis use disorders, yet social anxiety is unrelated to more frequent cannabis use. The lack of relation to cannabis use frequency may be at least partially due to lack of attention to cannabis use context. It may be that socially anxious persons engage in frequent solitary cannabis use, perhaps using before social situations in the hope that being intoxicated during the social event will help them feel less anxious. In fact, using cannabis alone has been associated with experiencing more cannabis-related problems in prior work. Methods The current study sought to identify whether solitary cannabis use frequency mediated the relationship between social anxiety and cannabis-related problems among 276 current cannabis using undergraduates who completed an online survey of putative predictors of substance use. Results Social anxiety was robustly related to more frequent solitary (but not social) cannabis use and solitary cannabis use frequency uniquely mediated the relation of social anxiety to cannabis use and related problems. Discussion and Conclusions Frequent solitary use appears to play an important role in the experience of cannabis-related problems among socially anxious persons. Scientific Significance Intervention strategies may benefit from targeting frequent solitary cannabis use, particularly among at-risk users such as those with elevated social anxiety. PMID:26890064
Carriot, F; Sasco, A J
Several publications have recently suggested a relationship between cannabis use and certain types of cancer. We gathered information on the latest findings on the subject. A manual and computerized bibliographic search on cannabis and cancer was conducted. In users under 40 years of age, cannabis is suspected to increase the risk of squamous-cell carcinoma of the upper aerodigestive tract, particularly of the tongue and larynx, and possibly of lung. Other tumours being suspected are non-lymphoblastic acute leukaemia and astrocytoma. In head and neck cancer, carcinogenicity was observed for regular (i.e. more than once a day for years) cannabis smokers. Moreover, cannabis increases the risk of head and neck cancer in a dose-response manner for frequency and duration of use. Interaction was observed with cigarette smoking and alcohol use. Delta9-THC seems to have a specific carcinogenic effect different from that of the pyrolysis products. Epidemiological studies are needed as soon as possible to provide data on the European and French situation. Information on the possible risks of a regular use of cannabis should be a priority.
Grover, Sandeep; Basu, Debasish
The study of cannabis use and psychopathology remains an interesting area from both academic and pragmatic perspectives. This article provides an update on the progress made in this area over the past decade or so. Psychopathology and psychiatric syndromes associated with cannabis use that have received research attention in recent years include cannabis withdrawal, cannabis and psychotic disorders (especially schizophrenia), depression, anxiety, and cognitive impairment. Status of a specific cannabis withdrawal syndrome and a specific ‘cannabis psychosis’ remains controversial. Current evidence indicates that there is a clinically significant association between cannabis use disorders and psychotic syndromes, depression, anxiety and possibly mild cognitive impairment. However, the nature of this association is often not clear. Several hypothesis related to the cannabis-schizophrenia association are examined. Cannabis use might be casually related to the later development of schizophrenia in an indirect way in a few heavy users, but more commonly, its use may precipitate disorders in persons who are vulnerable to developing psychosis and worsen the course of the disorder. PMID:21206788
This article describes the increasing risks of use of marijuana and related products by adolescents. As THC content increases and methods such as "dabbing" increase frequency of use, risks of marijuana use as perceived by youth are decreasing. At a time when marijuana access is increasing nationally, a new marijuana landscape is forming in which both adolescents and treatment providers must adjust their perceptions of what was once thought of as a "harmless" drug. This article describes this new landscape, and what it may mean for adolescent drug treatment.
Rial, Antonio; Gómez, Patricia; Picón, Eduardo; Braña, Teresa; Varela, Jesús
The percentages of adolescent Internet use in general terms have been measured for nearly two decades now; however, it might be thought that not every teenager behaves online in the same way. This study aims to identify the different types or profiles of adolescents and to characterize them from an attitudinal, behavioral and socio-demographic viewpoint. A questionnaire was applied to a representative sample of 2,339 Compulsory Secondary School students (M = 13.77 years old) from Galicia (a North-Western region of Spain) for this purpose. A two-stage cluster analysis, based on the response pattern in relation to their attitudes toward Internet, was carried out. Four different segments with specific characteristics were identified: the first steppers, the trainees, the sensible users, and the heavy users. Besides the relevance of descriptive data, these results are of particular interest at an applied level, because they could lead to a better fit of programs to prevent risky behaviors and problematic Internet use in adolescents.
Rushlow, Walter J.; Laviolette, Steven R.
Marijuana is the most widely used drug of abuse among adolescents. Adolescence is a vulnerable period for brain development, during which time various neurotransmitter systems such as the glutamatergic, GABAergic, dopaminergic, and endocannabinoid systems undergo extensive reorganization to support the maturation of the central nervous system (CNS). ▵-9-tetrahydrocannabinol (THC), the psychoactive component of marijuana, acts as a partial agonist of CB1 cannabinoid receptors (CB1Rs). CB1Rs are abundant in the CNS and are central components of the neurodevelopmental changes that occur during adolescence. Thus, overactivation of CB1Rs by cannabinoid exposure during adolescence has the ability to dramatically alter brain maturation, leading to persistent and enduring changes in adult cerebral function. Increasing preclinical evidence lends support to clinical evidence suggesting that chronic adolescent marijuana exposure may be associated with a higher risk for neuropsychiatric diseases, including schizophrenia. In this review, we present a broad overview of current neurobiological evidence regarding the long-term consequences of adolescent cannabinoid exposure on adult neuropsychiatric-like disorders. PMID:27254841
The cannabis plant has been known to humanity for centuries as a remedy for pain, diarrhea and inflammation. Current research is inspecting the use of cannabis for many diseases, including multiple sclerosis, epilepsy, dystonia, and chronic pain. In inflammatory conditions cannabinoids improve pain in rheumatoid arthritis and:pain and diarrhea in Crohn's disease. Despite their therapeutic potential, cannabinoids are not free of side effects including psychosis, anxiety, paranoia, dependence and abuse. Controlled clinical studies investigating the therapeutic potential of cannabis are few and small, whereas pressure for expanding cannabis use is increasing. Currently, as long as cannabis is classified as an illicit drug and until further controlled studies are performed, the use of medical cannabis should be limited to patients who failed conventional better established treatment.
Buckner, Julia D.; Zvolensky, Michael J.
Background and Objectives Social anxiety appears to be a risk factor for cannabis-related problems. Socially anxious individuals are vulnerable to using cannabis to cope in social situations and to avoiding social situations if marijuana is unavailable. Yet, the relative impact of cannabis use to cope with social anxiety relative to use to cope with negative affect more broadly has yet to be examined. Methods The present study used the Marijuana to Cope with Social Anxiety Scale (MCSAS) to examine the incremental validity of using cannabis use to cope in social situations (MCSAS-Cope) and avoidance of social situations if cannabis is unavailable (MCSAS-Avoid) in a community-recruited sample of 123 (34.1% female) current cannabis users. Results After controlling for age of first cannabis use, gender, alcohol and tobacco use, other cannabis use motives, and cannabis expectancies, MCSAS-Cope remained significantly positively related to cannabis use frequency and cannabis-related problems. After controlling for age of first cannabis use, gender, alcohol and tobacco use, and experiential avoidance, MCSAS-Avoid remained significantly related to cannabis problems but not frequency. Discussion and Conclusions The present findings suggest that cannabis use to manage social forms of anxiety may be important to understanding cannabis use behaviors. Scientific Significance The current findings identify cognitive/motivational factors implicated in more frequent cannabis use and in cannabis-related impairment, which may be essential to inform efforts to further refine prevention and treatment efforts. PMID:25196146
Zarfin, Yehoshua; Yefet, Enav; Abozaid, Said; Nasser, Wael; Mor, Tamer; Finkelstein, Yoram
We report on an infant who was admitted to hospital with severe neurological symptoms following passive inhalation of cannabis. To date, cannabis abuse has been described almost entirely in adolescents and adults. In early childhood, however, cannabis effects were almost exclusively discussed in the context of maternal prenatal exposure, and the…
Dervaux, Alain; Krebs, Marie-Odile; Laqueille, Xavier
Several studies have shown that Δ-9-THC the main psychoactive constituent of cannabis, can impair cognitive functions, especially attention, episodic memory, working memory and executive functions. These impairments have been related to the duration, frequency, dose and age at onset of cannabis use. Cognitive deficits may disappear with abstinence, but abnormalities may be long-lasting in subjects who began smoking cannabis before age 15. The lifetime prevalence of cannabis use disorders is about 1% in the general population. The main characteristics of cannabis use disorders are craving, persistent desire or unsuccessful efforts to cut down or control cannabis use, and persistent avoidance of familial, social occupational or recreational activities because of cannabis use. Nine prospective longitudinal studies in the generalpopulation have shown that cannabis use is associated with a two-fold increase in the risk of psychotic disorders, particularly schizophrenia, compared to controls. The risk of psychosis increases in a dose-related fashion. A higher risk of schizophrenia is predicted by earlier onset of cannabis use. The effects of cannabis are exerted primarily through THC interaction with cannabinoid (CB) 1 receptors in the brain. Cannabis exposure may disrupt the last steps of brain maturation, through the endocannabinoid system, thereby increasing the risk of psychosis during adolescence.
Millsaps, Cheryl L.; And Others
Describes research involving adolescent marijuana abusers. Using Wechsler Memory Scale-Revised and Wechsler Adult Intelligence Scale-Revised found characteristics consistent with pattern produced by cerebral dysfunction including reduced memory indices in relation to intellectual function and attentional ability. Intelligence was found to be in…
Danovitch, Itai; Gorelick, David A
The treatment of cannabis dependence can be viewed as a cup half empty or half full. On the one hand, few people who might benefit from treatment actually receive it. Among those who undergo treatment in randomized trials, long-term abstinence is achieved by fewer than 20%. Moderate use goals have been associated with decreases in consequences, but the differential impact of such goals on the long-term course of cannabis dependence is unknown. Optimal duration of treatment is unclear, and certain populations, particularly patients with co-occurring disorders, have not been studied adequately. Twelve-step programs are low cost, effective for other substance use disorders, and readily available in most regions of the world. However, their role and efficacy in cannabis dependence has not been examined. Finally, effective pharmacologic treatments are under development, but none have yet been firmly established. On the other hand, psychotherapeutic strategies used to treat other substance use disorders can be effective for cannabis dependence. A recent meta-analysis of psychosocial interventions for illicit substance use disorders found that treatments for cannabis dependence had comparatively larger effect sizes than treatments for other substance use disorders. Combination therapies have proven most effective, particularly those that begin with a motivational intervention, utilize incentives to enhance the commitment to change, and teach behavioral and cognitive copings skills to prevent relapse. Among adolescents, family engagement and collaboration with community stakeholders adds substantial value. Although only 9% of cannabis users develop cannabis dependence, the volume of people who smoke cannabis ensures that the total number of people in need of help is larger than the capacity of substance abuse specialty services. Thus, although efforts to refine and improve the efficacy of treatment interventions continue, innovations that increase the availability and
Løberg, Else-Marie; Hugdahl, Kenneth
People with schizophrenia frequently report cannabis use, and cannabis may be a risk factor for schizophrenia, mediated through effects on brain function and biochemistry. Thus, it is conceivable that cannabis may also influence cognitive functioning in this patient group. We report data from our own laboratory on the use of cannabis by schizophrenia patients, and review the existing literature on the effects of cannabis on cognition in schizophrenia and related psychosis. Of the 23 studies that were found, 14 reported that the cannabis users had better cognitive performance than the schizophrenia non-users. Eight studies reported no or minimal differences in cognitive performance in the two groups, but only one study reported better cognitive performance in the schizophrenia non-user group. Our own results confirm the overall impression from the literature review of better cognitive performance in the cannabis user group. These paradoxical findings may have several explanations, which are discussed. We suggest that cannabis causes a transient cognitive breakdown enabling the development of psychosis, imitating the typical cognitive vulnerability seen in schizophrenia. This is further supported by an earlier age of onset and fewer neurological soft signs in the cannabis-related schizophrenia group, suggesting an alternative pathway to psychosis. PMID:19956405
Moriarty, John; McVicar, Duncan; Higgins, Kathryn
Peer effects in adolescent cannabis are difficult to estimate, due in part to the lack of appropriate data on behaviour and social ties. This paper exploits survey data that have many desirable properties and have not previously been used for this purpose. The data set, collected from teenagers in three annual waves from 2002 to 2004 contains longitudinal information about friendship networks within schools (N = 5020). We exploit these data on network structure to estimate peer effects on adolescents from their nominated friends within school using two alternative approaches to identification. First, we present a cross-sectional instrumental variable (IV) estimate of peer effects that exploits network structure at the second degree, i.e. using information on friends of friends who are not themselves ego's friends to instrument for the cannabis use of friends. Second, we present an individual fixed effects estimate of peer effects using the full longitudinal structure of the data. Both innovations allow a greater degree of control for correlated effects than is commonly the case in the substance-use peer effects literature, improving our chances of obtaining estimates of peer effects than can be plausibly interpreted as causal. Both estimates suggest positive peer effects of non-trivial magnitude, although the IV estimate is imprecise. Furthermore, when we specify identical models with behaviour and characteristics of randomly selected school peers in place of friends', we find effectively zero effect from these 'placebo' peers, lending credence to our main estimates. We conclude that cross-sectional data can be used to estimate plausible positive peer effects on cannabis use where network structure information is available and appropriately exploited.
Shrivastava, Amresh; Johnston, Megan; Terpstra, Kristen; Bureau, Yves
Cannabis has been implicated as a risk factor for the development of schizophrenia, but the exact biological mechanisms remain unclear. In this review, we attempt to understand the neurobiological pathways that link cannabis use to schizophrenia. This has been an area of great debate; despite similarities between cannabis users and schizophrenia patients, the evidence is not sufficient to establish cause-and-effect. There have been advances in the understanding of the mechanisms of cannabis dependence as well as the role of the cannabinoid system in the development of psychosis and schizophrenia. The neurobiological mechanisms associated with the development of psychosis and effects from cannabis use may be similar but remain elusive. In order to better understand these associations, this paper will show common neurobiological and neuroanatomical changes as well as common cognitive dysfunction in cannabis users and patients of schizophrenia. We conclude that epidemiologic evidence highlights potential causal links; however, neurobiological evidence for causality remains weak.
... Professionals Questions to Ask about Your Treatment Research Cannabis and Cannabinoids (PDQ®)–Patient Version Overview Go to ... treatment (see Question 9 ). Questions and Answers About Cannabis What is Cannabis ? Cannabis , also known as marijuana , ...
Larsen, E; Rise, J; Lund, K E
The use of snus is increasing in Norway. In this study we examined differences between adolescents who were exclusive snus users, and adolescent non-users, smokers and dual users of snus and cigarettes on a number of psychosocial factors, categorized as risk variables and protective variables associated with involvement in health compromising behavior. We applied separate logistic regression models, where exclusive snus users (n=740) were compared with non-users (n=904), smokers (n=219), and dual users (n=367). Compared to non-users, the group of exclusive snus users was associated with variables traditionally predicting health risk behavior, such as smoking friends (OR=1.74, SD 1.27-2.38) and truancy (OR=2.12, SD 1.65-2.78). Compared to smokers, exclusive snus users were related to variables traditionally associated with protection against involvement in health risk behavior, e.g. higher academic orientation (OR=1.66, SD 1.12-2.45). Associations with protective factors were also observed when exclusive snus users were compared with dual users. While the group of exclusive snus users was associated with a pattern of psychosocial risk compared to non-users, they showed a more conventional pattern when compared to smokers and dual users. The group of exclusive snus users may be described on a continuum varying from psychosocial risk factors to protective factors of risk involvement depending on the group of comparison.
Hollister, L E
In this updating review of research on cannabis particular attention has been paid to the increasing number of studies of the disposition of the components of cannabis in man, as well as possible effects on health. Specific binding sites for cannaboids have not been demonstrated. Approximately 80 metabolites of tetrahydrocannabiol (THC) have been discovered, of which 11-OH-THC is the main metabolite, but it contributes little to the overall effect when the drug is smoked or given intravenously. The minimum plasma level of THC associated with the psychotropic effect is 25 ng/ml. Cannabis may produce directly an acute panic reaction, a toxic delirium, and acute paranoid state, or acute mania. Cannabis use may aggrevate schizophrenia, but it is much less certain whether it can lead to sociopathy or even to "amotivational syndrome". Despite widespread use of cannabis in virtually all parts of the world, no catastrophic effects on health have been noted. Cannabis appears to be relatively safe as compared with current social drugs. It is, however, still too early in the history of the present episode of cannabis use to be sanguine about possible bad effects.
Cannabis is the world's most widely cultivated and consumed illicit drug, but there remain major gaps in our understanding of global cannabis markets. For example, it appears that premium sinsemilla cannabis, often produced indoors in consumer countries, has become more potent in recent years and that its market share is also growing in some areas. This may be leading to greater localization of cannabis markets. It may also be responsible for the increase in the proportion of cannabis users in treatment populations at the international level. Assessing the extent and impact of this trend, however, is hampered both by a lack of international standards on issues such as terminology and by unanswered research questions. In order to arrive at accurate global estimates of the extent of production, there is a need for more scientific data on cannabis yields. On the demand side, more information is required on the question of cannabis dosage and volumes used by both occasional and regular users. Cannabis is not a uniform drug: the impact of using cannabis of differing potencies and chemical compositions needs to be researched. While issues concerning cannabis have been evaluated many times in the past, it remains a highly adaptable plant and, consequently, a dynamic drug, requiring constant reassessment.
Allsop, David J.; Copeland, Jan; Norberg, Melissa M.; Fu, Shanlin; Molnar, Anna; Lewis, John; Budney, Alan J.
Background and Aims Questions over the clinical significance of cannabis withdrawal have hindered its inclusion as a discrete cannabis induced psychiatric condition in the Diagnostic and Statistical Manual of Mental Disorders (DSM IV). This study aims to quantify functional impairment to normal daily activities from cannabis withdrawal, and looks at the factors predicting functional impairment. In addition the study tests the influence of functional impairment from cannabis withdrawal on cannabis use during and after an abstinence attempt. Methods and Results A volunteer sample of 49 non-treatment seeking cannabis users who met DSM-IV criteria for dependence provided daily withdrawal-related functional impairment scores during a one-week baseline phase and two weeks of monitored abstinence from cannabis with a one month follow up. Functional impairment from withdrawal symptoms was strongly associated with symptom severity (p = 0.0001). Participants with more severe cannabis dependence before the abstinence attempt reported greater functional impairment from cannabis withdrawal (p = 0.03). Relapse to cannabis use during the abstinence period was associated with greater functional impairment from a subset of withdrawal symptoms in high dependence users. Higher levels of functional impairment during the abstinence attempt predicted higher levels of cannabis use at one month follow up (p = 0.001). Conclusions Cannabis withdrawal is clinically significant because it is associated with functional impairment to normal daily activities, as well as relapse to cannabis use. Sample size in the relapse group was small and the use of a non-treatment seeking population requires findings to be replicated in clinical samples. Tailoring treatments to target withdrawal symptoms contributing to functional impairment during a quit attempt may improve treatment outcomes. PMID:23049760
Davis, Jordan P.; Smith, Douglas C.; Morphew, Jason W.; Lei, Xinrong; Zhang, Saijun
Very little prospective research investigates how cannabis withdrawal is associated with treatment outcomes, and this work has not used the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5) thresholds for cannabis withdrawal. The sample included 110 emerging adults entering outpatient substance use treatment who were heavy cannabis users with no other drug use and limited alcohol use. We used survival analyses to predict days to first use of cannabis and logistic regression to predict whether participants were abstinent and living in the community at 3 months. Those meeting criteria for cannabis withdrawal were more likely to return to use sooner than those not meeting criteria for cannabis withdrawal. However, the presence of cannabis withdrawal was not a significant predictor of 3-month abstinence. Emerging adults with DSM-5 cannabis withdrawal may have difficulty initiating abstinence in the days following their intake assessment, implying the need for strategies to mitigate their more rapid return to cannabis use. PMID:26877548
Popova, Lucy; Grana, Rachel; Zhao, Shirley; Chavez, Kathryn
Background Mobile technology is pervasive and widely used to obtain information about drugs such as cannabis, especially in a climate of rapidly changing cannabis policy; yet the content of available cannabis apps is largely unknown. Understanding the resources available to those searching for cannabis apps will clarify how this technology is being used to reflect and influence cannabis use behavior. Objective We investigated the content of 59 cannabis-related mobile apps for Apple and Android devices as of November 26, 2014. Methods The Apple and Google Play app stores were searched using the terms “cannabis” and “marijuana.” Three trained coders classified the top 20 apps for each term and each store, using a coding guide. Apps were examined for the presence of 20 content codes derived by the researchers. Results Total apps available for each search term were 124 for cannabis and 218 for marijuana in the Apple App Store, and 250 each for cannabis and marijuana on Google Play. The top 20 apps in each category in each store were coded for 59 independent apps (30 Apple, 29 Google Play). The three most common content areas were cannabis strain classification (33.9%), facts about cannabis (20.3%), and games (20.3%). In the Apple App Store, most apps were free (77%), all were rated “17+” years, and the average user rating was 3.9/5 stars. The most popular apps provided cannabis strain classifications (50%), dispensary information (27%), or general facts about cannabis (27%). Only one app (3%) provided information or resources related to cannabis abuse, addiction, or treatment. On Google Play, most apps were free (93%), rated “high maturity” (79%), and the average user rating was 4.1/5. The most popular app types offered games (28%), phone utilities (eg, wallpaper, clock; 21%) and cannabis food recipes (21%); no apps addressed abuse, addiction, or treatment. Conclusions Cannabis apps are generally free and highly rated. Apps were most often informational
Al-Shidhani, Thuraya A.; Arora, Vinita
We report a confirmed case of cannabis exposure in an Omani female child with developmental delay. Cannabis exposure in children can lead to many consequences; for example, chronic use can result in developmental delay, abnormal behaviour, and hyperactivity while there is a risk of coma with acute exposure. It is important for clinicians to consider substance abuse as a differential diagnosis for similar presentations in paediatric patients, noting that children are at risk of cannabis exposure if their parents/caregivers are cannabis users. PMID:22087402
Anthony, James C.; Lopez-Quintero, Catalina; Alshaarawy, Omayma
Background Globally, the most widely used set of compounds among the internationally regulated drugs is cannabis. Objective To review evidence from epidemiological research on cannabis, organized in relation to this field’s five main rubrics: quantity, location, causes, mechanisms, and prevention/control. Method The review covers a selection of evidence from standardized population surveys, official statistics, and governmental reports, as well as published articles and books identified via MEDLINE, Web of Science, and Google Scholar as of July 2016. Results In relation to quantity, an estimated 3% to 5% of the world population is thought to have tried a cannabis product, with at least one fairly recent use, mainly extra-medical and outside boundaries of prescribed use. Among cannabis users in the United States, roughly one in 7–8 has engaged in medical marijuana use. In relation to location, prevalence proportions reveal important variations across countries and between subgroups within countries. Regarding causes and mechanisms of starting to use cannabis, there is no compelling integrative and replicable conceptual model or theoretical formulation. Most studies of mechanisms have focused upon a ‘gateway sequence’ and person-to-person diffusion, with some recent work on disability-adjusted life years. A brief review of cannabis use consequences, as well as prevention and control strategies is also provided. Conclusion At present, we know much about the frequency and occurrence of cannabis use, with too little replicable definitive evidence with respect to the other main rubrics. Given a changing regulatory environment for cannabis products, new institutions such as an independent International Cannabis Products Safety Commission may be required to produce evidence required to weigh benefits versus costs. It is not clear that government sponsored research will be sufficient to meet consumer demand for balanced points of view and truly definitive evidence
Kuwayama, Kenji; Miyaguchi, Hajime; Yamamuro, Tadashi; Tsujikawa, Kenji; Kanamori, Tatsuyuki; Iwata, Yuko T; Inoue, Hiroyuki
We previously developed a simple and highly sensitive analytical method for 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol (THC-COOH) in spiked hair using micropulverized extraction (MPE) and liquid chromatography/tandem mass spectrometry (LC/MS/MS). Using this method, we were able to quantify THC-COOH at 0.2pg/mg, which is the cut-off level recommended by the Society of Hair Testing. However, it was impossible to prove the validity of the method and the presence of THC-COOH conjugated with glucuronide in hair because we did not have authentic hair containing THC-COOH at the cut-off levels at that time. In this study, the previously developed method was verified using recently obtained hair from a cannabis user. The concentrations of THC-COOH quantified using the method were 0.36±0.01pg/mg without hydrolyzation for glucuronide and 0.49±0.05pg/mg with hydrolyzation after MPE, whereas the concentration quantified using the conventional alkaline dissolution and gas chromatography/tandem mass spectrometry with negative ion chemical ionization was 0.50±0.02pg/mg. The results proved that THC-COOH could be extracted completely from authentic hair containing THC-COOH at the recommended cut-off level using MPE. In addition, MPE with and without hydrolyzation, unlike alkaline dissolution of hair, enabled the measurement of the percentage of the conjugate form in total THC-COOH. The percentage of conjugated THC-COOH in hair measured using the MPE was approximately 26%, which was greatly different from previously reported data (>75%). The discrimination between conjugated and unconjugated compounds in hair is important to understand the mechanism of drug uptakes into hair. More data obtained with our simple and highly sensitive method from the hair of cannabis users would help to understand the relationship of concentrations between THC-COOH and its conjugate in hair.
Background Psychostimulants and cannabis are two of the three most commonly used illicit drugs by young Australians. As such, it is important to deliver prevention for these substances to prevent their misuse and to reduce associated harms. The present study aims to evaluate the feasibility and effectiveness of the universal computer-based Climate Schools: Psychostimulant and Cannabis Module. Methods A cluster randomised controlled trial was conducted with 1734 Year 10 students (mean age = 15.44 years; SD = 0.41) from 21 secondary schools in Australia. Schools were randomised to receive either the six lesson computer-based Climate Schools program or their usual health classes, including drug education, over the year. Results The Climate Schools program was shown to increase knowledge of cannabis and psychostimulants and decrease pro-drug attitudes. In the short-term the program was effective in subduing the uptake and plateauing the frequency of ecstasy use, however there were no changes in meth/amphetamine use. In addition, females who received the program used cannabis significantly less frequently than students who received drug education as usual. Finally, the Climate Schools program was related to decreasing students’ intentions to use meth/amphetamine and ecstasy in the future, however these effects did not last over time. Conclusions These findings provide support for the use of a harm-minimisation approach and computer technology as an innovative platform for the delivery of prevention education for illicit drugs in schools. The current study indicated that teachers and students enjoyed the program and that it is feasible to extend the successful Climate Schools model to the prevention of other drugs, namely cannabis and psychostimulants. Trial registration Australian and New Zealand Clinical Trials Registry ACTRN12613000492752. PMID:24943829
Background MDFT (Multidimensional Family Therapy) is a family based outpatient treatment programme for adolescent problem behaviour. MDFT has been found effective in the USA in adolescent samples differing in severity and treatment delivery settings. On request of five governments (Belgium, France, Germany, the Netherlands, and Switzerland), MDFT has now been tested in the joint INCANT trial (International Cannabis Need of Treatment) for applicability in Western Europe. In each of the five countries, study participants were recruited from the local population of youth seeking or guided to treatment for, among other things, cannabis use disorder. There is little information in the literature if these populations are comparable between sites/countries or not. Therefore, we examined if the study samples enrolled in the five countries differed in baseline characteristics regarding demographics, clinical profile, and treatment delivery setting. Methods INCANT was a multicentre phase III(b) randomized controlled trial with an open-label, parallel group design. It compared MDFT with treatment as usual (TAU) at and across sites in Berlin, Brussels, Geneva, The Hague and Paris. Participants of INCANT were adolescents of either sex, from 13 through 18 years of age, with a cannabis use disorder (dependence or abuse), and at least one parent willing to take part in the treatment. In total, 450 cases/families were randomized (concealed) into INCANT. Results We collected data about adolescent and family demographics (age, gender, family composition, school, work, friends, and leisure time). In addition, we gathered data about problem behaviour (substance use, alcohol and cannabis use disorders, delinquency, psychiatric co-morbidity). There were no major differences on any of these measures between the treatment conditions (MDFT and TAU) for any of the sites. However, there were cross-site differences on many variables. Most of these could be explained by variations in treatment
Ross, J. Megan; Coxe, Stefany; Schuster, Randi M.; Rojas, Angelica; Gonzalez, Raul
Risky sexual behavior (RSB) is a current public health concern affecting adolescents and young adults. Conduct disorder, cannabis use and decision making (DM) ability are interrelated constructs that are relevant to RSB; however, there is little research on the association of DM and RSB. Participants were 79 cannabis users assessed through self-report measures of RSB and mental health, and a timeline follow-back procedure for substance use. DM ability was assessed via the Iowa Gambling Task. We found that more conduct disorder symptoms accounted for unique variance in measures of overall RSB and an earlier initiation of oral sex, even when taking into account DM and cannabis use. Amount of cannabis use and DM ability moderated the relationships between number of conduct disorder symptoms and number of oral sex partners and age of initiation for vaginal sex. An increase in conduct disorder symptoms was associated with more oral sex partners when DM was poor and fewer partners when DM was better, however this relationship was only present at higher levels of cannabis use. Furthermore, when DM was poor, more conduct disorder symptoms predicted a younger age of initiation of vaginal sex, with the age decreasing as amount of cannabis use increased. Determining how DM influences RSB may assist in the identification of novel treatment approaches to reduce engagement in RSB. PMID:25832553
Ross, J Megan; Coxe, Stefany; Schuster, Randi M; Rojas, Angelica; Gonzalez, Raul
Risky sexual behavior (RSB) is a current public health concern affecting adolescents and young adults. Conduct disorder, cannabis use, and decision-making (DM) ability are interrelated constructs that are relevant to RSB; however, there is little research on the association of DM and RSB. Participants were 79 cannabis users assessed through self-report measures of RSB and mental health and a timeline follow-back procedure for substance use. DM ability was assessed via the Iowa Gambling Task. We found that more conduct disorder symptoms accounted for unique variance in measures of overall RSB and an earlier initiation of oral sex, even when taking into account DM and cannabis use. Amount of cannabis use and DM ability moderated the relationships between number of conduct disorder symptoms and number of oral sex partners and age of initiation for vaginal sex. An increase in conduct disorder symptoms was associated with more oral sex partners when DM was poor and fewer partners when DM was better; however, this relationship was only present at higher levels of cannabis use. Furthermore, when DM was poor, more conduct disorder symptoms predicted a younger age of initiation of vaginal sex, with the age decreasing as amount of cannabis use increased. Determining how DM influences RSB may assist in the identification of novel treatment approaches to reduce engagement in RSB.
Poulsen, H A; Sutherland, G J
The potency of cannabis plant and cannabis products seized in New Zealand over the period of 20 years is studied. The earlier part of the study includes mainly imported cannabis oil and cannabis resin, and both imported and locally grown cannabis plant, that was seized by the police. The later part of the study includes little imported material. Cannabis plant is now locally grown, cannabis oil is locally manufactured and imported cannabis resin is rarely seized. The average potency of the cannabis plant available to the user has not increased over the 20 years period. Cannabis leaf contains on average 1% THC and the female flowering heads on average 3.5% THC. The average potency of cannabis oil has dropped from its peak at 34% THC in 1985 to 13% THC in 1995.
King, Keith A.; Merianos, Ashley L.; Vidourek, Rebecca A.
Background: Because marijuana is becoming more accessible and perceived norms of use are becoming increasingly more favorable, research is needed to understand characteristics of marijuana acquisition among adolescents. Purpose: The study purpose was to examine whether sources and locations where adolescent users obtain and use marijuana differed…
Holt, Colleen M.; Dowell, Richard C.
This study examined changes to speech production in adolescents with hearing impairment following a period of actor vocal training. In addition to vocal parameters, the study also investigated changes to psychosocial factors such as confidence, self-esteem, and anxiety. The group were adolescent users of cochlear implants (mean age at commencement…
Cole, Jon C; Goudie, Andrew J; Field, Matt; Loverseed, Anne-Claire; Charlton, Sarah; Sumnall, Harry R
Previous research has indicated that non-dependent polydrug users are willing to pay more money to buy good quality drugs as their income increased. This study sought to examine whether altering the perceived quality of controlled drugs would affect drug purchases if the monetary price remained fixed. A random sample of 80 polydrug users were recruited. All participants were administered an anonymous questionnaire consisting of the Drug Abuse Screening Test for Adolescents (DAST-A), the Severity of Dependence Scale for cannabis (SDS), the Alcohol Use Disorders Identification Test (AUDIT), the Hospital Anxiety and Depression Scale (HADS), and questions about their drug use. Participants then completed a simulation of controlled drug purchases where the price of alcohol, amphetamine, cannabis, cocaine, and ecstasy remained the same but their perceived quality changed (i.e. unit price increased as the perceived quality decreased). The demand for alcohol was quality inelastic and alcohol quality had no effects on the purchase of any other controlled drug. Demand for cannabis was quality elastic and alcohol substituted for cannabis as its unit price increased. Demand for cocaine was quality elastic and alcohol, cannabis, and ecstasy substituted for cocaine as its unit price increased. Demand for ecstasy was quality elastic and alcohol and cocaine both substituted for ecstasy as its unit price increased. These results suggest that perceived quality influences the demand for controlled drugs and that monitoring the perceived quality of controlled drugs may provide a warning of potential public health problems in the near future.
Copeland, Jan; Swift, Wendy
This paper provides an overview of the epidemiology of cannabis use, cannabis use disorders and its treatment. Cannabis is the most commonly used illicit drug internationally. While use is decreasing in the developed world, it appears to be stable or increasing in developing countries and some indigenous communities. Early initiation and regular adolescent use have been identified as particular risk factors for later problematic cannabis (and other drug) use, impaired mental health, delinquency, lower educational achievement, risky sexual behaviour and criminal offending in a range of studies. It is estimated that approximately one in ten people who had ever used cannabis will become dependent with risk increasing markedly with frequency of use. There has been an increase in the proportion of treatment provided for cannabis use. There are as yet no evidence-based pharmacotherapies available for the management of cannabis withdrawal and craving. Relatively brief cognitive behavioural therapy and contingency management have the strongest evidence of success, and structured, family-based interventions, provide potent treatment options for adolescents. With criminally involved young people and those with severe, persistent mental illness, longer and more intensive therapies provided by interdisciplinary teams may be required.
van Ours, Jan C; Williams, Jenny
This paper uses duration models and self-reported cannabis histories from young Australians to study the dynamics of cannabis use. We find that low cannabis prices are associated with early initiation into cannabis use. While the decision to quit does not appear to be directly influenced by price, we find that the younger an individual is when they start using cannabis the less likely they are to quit. Therefore, low cannabis prices lead to early use and because of that they lead to a low quit rate and hence a longer duration of use.
de Sousa Fernandes Perna, Elizabeth B; Theunissen, Eef L; Kuypers, Kim P C; Evers, Elisabeth A; Stiers, Peter; Toennes, Stefan W; Witteman, Jurriaan; van Dalen, Wim; Ramaekers, Johannes G
Drugs of abuse stimulate striatal dopamine release and activate reward pathways. This study examined the impact of alcohol and cannabis marketing on the reward circuit in alcohol and cannabis users while sober and intoxicated. It was predicted that alcohol and cannabis marketing would increase striatal activation when sober and that reward sensitivity would be less during alcohol and cannabis intoxication. Heavy alcohol (n = 20) and regular cannabis users (n = 21) participated in a mixed factorial study involving administration of alcohol and placebo in the alcohol group and cannabis and placebo in the cannabis group. Non-drug users (n = 20) served as between group reference. Brain activation after exposure to alcohol and cannabis marketing movies was measured using functional magnetic resonance imaging and compared between groups while sober and compared with placebo while intoxicated. Implicit alcohol and cannabis cognitions were assessed by means of a single-category implicit association test. Alcohol and cannabis marketing significantly increased striatal BOLD activation across all groups while sober. Striatal activation however decreased during intoxication with alcohol and cannabis. Implicit associations with cannabis marketing cues were significantly more positive in alcohol and cannabis users as compared with non-drug using controls. Public advertising of alcohol or cannabis use elicits striatal activation in the brain's reward circuit. Reduction of marketing would reduce brain exposure to reward cues that motivate substance use. Conversely, elevated dopamine levels protect against the reinforcing potential of marketing.
Gilman, Jodi M.; Calderon, Vanessa; Curran, Max T.; Evins, A. Eden
BACKGROUND Though substance use is often associated with elevated risk-taking in real-world scenarios, many risk-taking tasks in experimental psychology using financial gambles fail to find significant differences between individuals with substance use disorders and healthy controls. We assessed whether participants using marijuana would show a greater propensity for risk-taking in distinct domains including, but not limited to, financial risk-taking. METHODS In the current study, we assessed risk-taking in young adult (age 18–25) regular marijuana users and in non-using control participants using a domain-specific risk-taking self-report scale (DOSPERT) encompassing five domains of risk-taking (social, financial, recreational, health/safety, and ethical). We also measured behavioral risk-taking using a laboratory monetary risk-taking task. RESULTS Marijuana users and controls reported significant differences on the social, health/safety, and ethical risk-taking scales, but no differences in the propensity to take recreational or financial risks. Complementing the self-report finding, there were no differences between marijuana users and controls in their performance on the laboratory risk-taking task. CONCLUSIONS These findings suggest that financial risk-taking may be less sensitive than other domains of risk-taking in assessing differences in risky behavior between those who use marijuana and those who do not. In order to more consistently determine whether increased risk-taking is a factor in substance use, it may be necessary to use both monetary risk-taking tasks and complementary assessments of non-monetary-based risk-taking measures. PMID:25577478
Crocker, C E; Tibbo, P G
A common viewpoint has proliferated that cannabis use is mostly harmless. Some argue that by not supporting its use, we are missing a great therapeutic opportunity. The general public view on cannabis may partially be a result of poor knowledge translation. In fact, the "war on drugs" approach has not allowed for basic education on the varied effects of cannabis on the brain, especially at highly critical phases of brain development such as adolescence.
Hall, W; Weier, M
A major challenge in assessing the public health impact of legalizing cannabis use in Colorado and Washington State is the absence of any experience with legal cannabis markets. The Netherlands created a de facto legalized cannabis market for recreational use, but policy analysts disagree about how it has affected rates of cannabis use. Some US states have created de facto legal supply of cannabis for medical use. So far this policy does not appear to have increased cannabis use or cannabis-related harm. Given experience with more liberal alcohol policies, the legalization of recreational cannabis use is likely to increase use among current users. It is also likely that legalization will increase the number of new users among young adults but it remains uncertain how many may be recruited, within what time frame, among which groups within the population, and how many of these new users will become regular users.
Bava, Sunita; Jacobus, Joanna; Mahmood, Omar; Yang, Tony T.; Tapert, Susan F.
Background: Progressive myelination during adolescence implicates an increased vulnerability to neurotoxic substances and enduring neurocognitive consequences. This study examined the cognitive manifestations of altered white matter microstructure in chronic marijuana and alcohol-using (MJ + ALC) adolescents. Methods: Thirty-six MJ + ALC…
Santos, Rui Pedro; Resende, Cristina Isabel Pinho; Vieira, Ana Paula; Brito, Celeste
Cannabis arteritis (CA) is a major and underdiagnosed cause of peripheral arterial disease in young patients. A 34-year-old man, daily smoker of 20 cigarettes and two cannabis cigarettes for 14 years, presented with a necrotic plaque of left hallux for 3 weeks. The Doppler ultrasound and angiography were compatible with severe Buerger's disease. Submitted to a revascularisation procedure and hypocoagulation with rivaroxaban. He had ceased smoking but maintained consumption of cannabis. Owing to the persistence of distal necrosis, amputation of the hallux was performed with good evolution. CA is a subtype of Buerger's disease. It is poorly known but increasingly prevalent and manifests in cannabis users regardless of tobacco use. The drug is considered at least a cofactor of the arteriopathy. The most effective treatment is cessation of consumption. Being cannabis one of the most consumed drugs, its mandatory to ask about its use in all young patients with arteriopathy.
Summary A number of therapeutic uses of cannabis and its derivatives have been postulated from preclinical investigations. Possible clinical indications include spasticity and pain in multiple sclerosis, cancer-associated nausea and vomiting, cancer pain and HIV neuropathy. However, evidence is limited, may reflect subjective rather than objective outcomes, and is not conclusive. Controversies lie in how to produce, supply and administer cannabinoid products. Introduction of cannabinoids therapeutically should be supported by a regulatory and educational framework that minimises the risk of harm to patients and the community. The Regulator of Medicinal Cannabis Bill 2014 is under consideration in Australia to address this. Nabiximols is the only cannabinoid on the Australian Register of Therapeutic Goods at present, although cannabidiol has been recommended for inclusion in Schedule 4. PMID:26843715
A number of therapeutic uses of cannabis and its derivatives have been postulated from preclinical investigations. Possible clinical indications include spasticity and pain in multiple sclerosis, cancer-associated nausea and vomiting, cancer pain and HIV neuropathy. However, evidence is limited, may reflect subjective rather than objective outcomes, and is not conclusive. Controversies lie in how to produce, supply and administer cannabinoid products. Introduction of cannabinoids therapeutically should be supported by a regulatory and educational framework that minimises the risk of harm to patients and the community. The Regulator of Medicinal Cannabis Bill 2014 is under consideration in Australia to address this. Nabiximols is the only cannabinoid on the Australian Register of Therapeutic Goods at present, although cannabidiol has been recommended for inclusion in Schedule 4.
Foster, Dawn W.; Ecker, Anthony H.; Zvolensky, Michael J.; Buckner, Julia D.
Objectives Socially anxious cannabis users are influenced by cannabis expectancies and normative perceptions. The present study examines the influence of psychosocial factors on cannabis use vulnerability factors as the result of interactions between norms perceptions, social anxiety, and expectancies. Methods Participants were 149 (36.2% female) current cannabis users aged 18-36 (M=21.01, SD=3.09). Hierarchical multiple regressions were employed to investigate the predictive value of the social anxiety X injunctive norms X expectancies interaction on cannabis cravings. Results A three-way interaction emerged in the prediction of cannabis cravings. Simple slopes analyses showed that among individuals with perceptions of greater parent approval of cannabis use (higher injunctive norms), social anxiety was associated with greater cannabis craving when expectancies regarding relaxation and tension reduction were greater (t=2.54, p=.01, β=1.12). Conclusions Among cannabis users with perceptions of greater injunctive norms, social anxiety was associated with greater cannabis craving when tension reduction expectancies were greater. However, social anxiety was unrelated to cannabis craving when expectances were low. This suggests that cannabis craving among socially anxious adults was greatest when cannabis use was viewed as acceptable and expected to reduce tension, and highlights the importance of considering norms, expectancies, and social anxiety in understanding cannabis-related behaviors. PMID:26586926
Cannabis is popularly believed to be a relatively benign substance. Cannabis is also considered to have potential medical benefits, and medical marijuana has been legislated in many parts of the world. However, a recent meta-analysis found that cannabinoids were associated with only modest benefits for chemotherapy-related nausea and vomiting, small and inconsistent benefits for pain and spasticity, and inconclusive benefits for other indications such as improvement of appetite and weight, reduction in tic severity, and improvement of mood or sleep. On the flip side, cannabinoids and cannabis have acute and long-term adverse effects. In randomized controlled trials, cannabinoids increase the risk of total adverse events, serious adverse events, and dropout due to adverse events. Cannabis impairs cognition, and driving after cannabis use is associated with an increased risk of traffic accidents, including fatal accidents. Long-term cannabis use may lead to dependence, respiratory conditions, psychosis, and possibly cancer, as well. Cannabis use during pregnancy may compromise certain pregnancy outcomes such as fetal growth, and use during adolescence may compromise neurodevelopment, social adjustment, and vocational success. The composition and bioavailability of cannabis vary across preparations of the substance and routes of administration; this limits the ability to generalize the findings of studies. The findings of older research may no longer apply to current strains of cannabis that are higher in psychotogenic content. It is important for medical professionals and the lay public to understand the limitations of the efficacy data and the seriousness of the risks associated with cannabis use in medical and recreational contexts.
Plancherel, Bernard; Bolognini, Monique; Stephan, Philippe; Laget, Jacques; Chinet, Leonie; Bernard, Mathieu; Halfon, Olivier
A questionnaire investigating adolescents' opinions and experiences regarding marijuana use was administered to 163 adolescents and young adults (96 boys and 67 girls) aged 13 to 20 (mean age = 16.8, s.d. = 1.5). Items referred to marijuana and other substances' dangerousness, representations regarding the positive and negative consequences of…
Petersen, Bjørn; Weed, Ethan; Sandmann, Pascale; Brattico, Elvira; Hansen, Mads; Sørensen, Stine Derdau; Vuust, Peter
Cochlear implants (CIs) are primarily designed to assist deaf individuals in perception of speech, although possibilities for music fruition have also been documented. Previous studies have indicated the existence of neural correlates of residual music skills in postlingually deaf adults and children. However, little is known about the behavioral and neural correlates of music perception in the new generation of prelingually deaf adolescents who grew up with CIs. With electroencephalography (EEG), we recorded the mismatch negativity (MMN) of the auditory event-related potential to changes in musical features in adolescent CI users and in normal-hearing (NH) age mates. EEG recordings and behavioral testing were carried out before (T1) and after (T2) a 2-week music training program for the CI users and in two sessions equally separated in time for NH controls. We found significant MMNs in adolescent CI users for deviations in timbre, intensity, and rhythm, indicating residual neural prerequisites for musical feature processing. By contrast, only one of the two pitch deviants elicited an MMN in CI users. This pitch discrimination deficit was supported by behavioral measures, in which CI users scored significantly below the NH level. Overall, MMN amplitudes were significantly smaller in CI users than in NH controls, suggesting poorer music discrimination ability. Despite compliance from the CI participants, we found no effect of the music training, likely resulting from the brevity of the program. This is the first study showing significant brain responses to musical feature changes in prelingually deaf adolescent CI users and their associations with behavioral measures, implying neural predispositions for at least some aspects of music processing. Future studies should test any beneficial effects of a longer lasting music intervention in adolescent CI users.
Petersen, Bjørn; Weed, Ethan; Sandmann, Pascale; Brattico, Elvira; Hansen, Mads; Sørensen, Stine Derdau; Vuust, Peter
Cochlear implants (CIs) are primarily designed to assist deaf individuals in perception of speech, although possibilities for music fruition have also been documented. Previous studies have indicated the existence of neural correlates of residual music skills in postlingually deaf adults and children. However, little is known about the behavioral and neural correlates of music perception in the new generation of prelingually deaf adolescents who grew up with CIs. With electroencephalography (EEG), we recorded the mismatch negativity (MMN) of the auditory event-related potential to changes in musical features in adolescent CI users and in normal-hearing (NH) age mates. EEG recordings and behavioral testing were carried out before (T1) and after (T2) a 2-week music training program for the CI users and in two sessions equally separated in time for NH controls. We found significant MMNs in adolescent CI users for deviations in timbre, intensity, and rhythm, indicating residual neural prerequisites for musical feature processing. By contrast, only one of the two pitch deviants elicited an MMN in CI users. This pitch discrimination deficit was supported by behavioral measures, in which CI users scored significantly below the NH level. Overall, MMN amplitudes were significantly smaller in CI users than in NH controls, suggesting poorer music discrimination ability. Despite compliance from the CI participants, we found no effect of the music training, likely resulting from the brevity of the program. This is the first study showing significant brain responses to musical feature changes in prelingually deaf adolescent CI users and their associations with behavioral measures, implying neural predispositions for at least some aspects of music processing. Future studies should test any beneficial effects of a longer lasting music intervention in adolescent CI users. PMID:25705185
Wetherill, Reagan R.; Hager, Nathan; Jagannathan, Kanchana; Mashhoon, Yasmin; Pater, Heather; Childress, Anna Rose; Franklin, Teresa R.
Addiction theories posit that addiction is the result of a progressive transition from voluntary to habitual, compulsive drug use—changes that have been linked, in animals, to a shift from ventral to dorsal striatal control over drug-seeking behavior. Thus, we hypothesized that early-onset (EOs) cannabis users versus late-onset (LOs) cannabis users might exhibit, respectively, greater dorsal versus ventral striatal response to drug cues. We used functional magnetic resonance imaging and an event-related blood oxygen level-dependent backward-masking task to evaluate striatal responses to backward-masked cannabis cues (vs. neutral cues) in EOs (<16 years old, n = 15) and LOs (≥16 years old, n = 26) with similar recent cannabis use patterns. Direct comparisons revealed that EOs showed greater response to cannabis cues in the dorsal striatum than LOs (p < 0.01, k > 50 voxels). Within-group analyses revealed that EOs showed greater neural response to cannabis cues in the dorsal striatum, whereas LOs exhibited greater neural response to cannabis cues in the ventral striatum. Although cross-sectional, these findings are consistent with recent addiction theories suggesting a progressive shift from ventral to dorsal striatal control over drug-seeking behavior and highlight the importance of age of onset of cannabis use on the brain and cognition. PMID:28331903
Sullivan, Nicholas; Elzinga, Sytze; Raber, Jeffrey C.
The present study was conducted in order to quantify to what extent cannabis consumers may be exposed to pesticide and other chemical residues through inhaled mainstream cannabis smoke. Three different smoking devices were evaluated in order to provide a generalized data set representative of pesticide exposures possible for medical cannabis users. Three different pesticides, bifenthrin, diazinon, and permethrin, along with the plant growth regulator paclobutrazol, which are readily available to cultivators in commercial products, were investigated in the experiment. Smoke generated from the smoking devices was condensed in tandem chilled gas traps and analyzed with gas chromatography-mass spectrometry (GC-MS). Recoveries of residues were as high as 69.5% depending on the device used and the component investigated, suggesting that the potential of pesticide and chemical residue exposures to cannabis users is substantial and may pose a significant toxicological threat in the absence of adequate regulatory frameworks. PMID:23737769
Kim, Jieun E; Kim, Geon Ha; Hwang, Jaeuk; Kim, Jung Yoon; Renshaw, Perry F; Yurgelun-Todd, Deborah A; Kim, Binna; Kang, Ilhyang; Jeon, Saerom; Ma, Jiyoung; Lyoo, In Kyoon; Yoon, Sujung
The adolescent brain, with ongoing prefrontal maturation, may be more vulnerable to drug use-related neurotoxic changes as compared to the adult brain. We investigated whether the use of methamphetamine (MA), a highly addictive psychostimulant, during adolescence affect metabolic and cognitive functions of the anterior cingulate cortex (ACC). In adolescent MA users (n = 44) and healthy adolescents (n = 53), the levels of N-acetyl aspartate (NAA), a neuronal marker, were examined in the ACC using proton magnetic resonance spectroscopy. The Stroop color-word task was used to assess Stroop interference, which may reflect cognitive functions of behavior monitoring and response selection that are mediated by the ACC. Adolescent MA users had lower NAA levels in the ACC (t = -2.88, P = 0.005) and relatively higher interference scores (t = 2.03, P = 0.045) than healthy adolescents. Moreover, there were significant relationships between lower NAA levels in the ACC and worse interference scores in adolescent MA users (r = -0.61, P < 0.001). Interestingly, early onset of MA use, as compared to late onset, was related to both lower NAA levels in the ACC (t = -2.24, P = 0.03) as well as lower performance on interference measure of the Stroop color-word task (t = 2.25, P = 0.03). The current findings suggest that metabolic dysfunction in the ACC and its related cognitive impairment may play an important role in adolescent-onset addiction, particularly during early adolescence.
Norberg, Melissa M; Battisti, Robert A; Copeland, Jan; Hermens, Daniel F; Hickie, Ian B
The aim of the current study was to delineate the psychiatric profile of cannabis dependent young people (14-29 years old) with mental health problems (N = 36) seeking treatment via a research study. To do so, the Structured Clinical Interview for DSM-IV-TR Axis I Disorders and the Structured Clinical Interview for DSM-IV Childhood Diagnoses were used to obtain DSM-IV diagnoses, while a modified Timeline Followback interview and self-reports were used to measure cannabis use, cannabis-related problems, and impairment. Most individuals had at least two Axis I disorders in addition to cannabis dependence. Anxiety disorders were common, with posttraumatic stress disorder, social phobia, and generalised anxiety disorder accounting for the majority of these diagnoses. On average, young people reported a moderate degree of dependence and functional impairment, and a substantial number of cannabis-related problems. Although both males and females reported using similar quantities of cannabis per month, females reported using cannabis more frequently than males. The current data suggest that young people who present for cannabis use treatment in the context of a mental health issue may have a variety of psychiatric problems that need addressed and that males and females may have slightly different profiles. If cannabis use treatments are to advance for this population, more attention needs to be paid to the complex issues that young people present to treatment with.
Van Laar, Margriet; Van Der Pol, Peggy; Niesink, Raymond
The Netherlands has seen an increase in Δ9-tetrahydrocannabinol (THC) concentrations from approximately 8% in the 1990s up to 20% in 2004. Increased cannabis potency may lead to higher THC-exposure and cannabis related harm. The Dutch government officially condones the sale of cannabis from so called 'coffee shops', and the Opium Act distinguishes cannabis as a Schedule II drug with 'acceptable risk' from other drugs with 'unacceptable risk' (Schedule I). Even in 1976, however, cannabis potency was taken into account by distinguishing hemp oil as a Schedule I drug. In 2011, an advisory committee recommended tightening up legislation, leading to a 2013 bill proposing the reclassification of high potency cannabis products with a THC content of 15% or more as a Schedule I drug. The purpose of this measure was twofold: to reduce public health risks and to reduce illegal cultivation and export of cannabis by increasing punishment. This paper focuses on the public health aspects and describes the (explicit and implicit) assumptions underlying this '15% THC measure', as well as to what extent these are supported by scientific research. Based on scientific literature and other sources of information, we conclude that the 15% measure can provide in theory a slight health benefit for specific groups of cannabis users (i.e., frequent users preferring strong cannabis, purchasing from coffee shops, using 'steady quantities' and not changing their smoking behaviour), but certainly not for all cannabis users. These gains should be weighed against the investment in enforcement and the risk of unintended (adverse) effects. Given the many assumptions and uncertainty about the nature and extent of the expected buying and smoking behaviour changes, the measure is a political choice and based on thin evidence.
Kelly, Clare; Castellanos, F Xavier; Tomaselli, Olivia; Lisdahl, Krista; Tamm, Leanne; Jernigan, Terry; Newman, Erik; Epstein, Jeffery N; Molina, Brooke S G; Greenhill, Laurence L; Potkin, Steven G; Hinshaw, Stephen; Swanson, James M
One of the most salient long-term implications of a childhood diagnosis of ADHD is an increased risk for substance use, abuse, or dependence in adolescence and adulthood. The extent to which cannabis use affects ADHD-related alterations in brain functional organization is unknown, however. To address this research gap, we recruited a sample of 75 individuals aged 21-25 years with and without a childhood diagnosis of ADHD Combined Type, who were either frequent users or non-users of cannabis. These participants have been followed longitudinally since age 7-9.9 years as part of a large multi-site longitudinal study of ADHD, the Multimodal Treatment Study of Children with ADHD (MTA). We examined task-independent intrinsic functional connectivity (iFC) within 9 functional networks using a 2 × 2 design, which compared four groups of participants: (1) individuals with a childhood diagnosis of ADHD who currently use cannabis (n = 23); (2) individuals with ADHD who do not currently use cannabis (n = 22); (3) comparisons who currently use cannabis (n = 15); and (4) comparisons who do not currently use cannabis (n = 15). The main effects of childhood ADHD were primarily weakened iFC in networks supporting executive function and somatomotor control. Contrary to expectations, effects of cannabis use were distinct from those of diagnostic group and no interactions were observed. Exploratory brain-behavior analyses suggested that ADHD-related effects were primarily linked with poorer neurocognitive performance. Deficits in the integrity of functional networks supporting executive function and somatomotor control are consistent with the phenotypic and neurocognitive features of ADHD. Our data suggest that cannabis use does not exacerbate ADHD-related alterations, but this finding awaits replication in a larger sample. Longitudinal neuroimaging studies are urgently required to delineate the neurodevelopmental cascade that culminates in positive and negative outcomes
Gaete, Jorge; Araya, Ricardo
We studied the association between individual and contextual variables and the use of tobacco, alcohol, or cannabis in the last 30 days preceding the study, considering the hierarchical nature of students nested in schools. We used the 7th Chilean National School Survey of Substance Use (2007) covering 45,273 students (aged 12-21 years old) along with information from 1465 schools provided by the Chilean Ministry of Education. Multilevel univariable and multivariable logistic regression models were performed. We found a significant intra-class correlation within schools for all substances in the study. Common (e.g., availability of pocket money, more time spent with friends, poor parental monitoring, poor school bonding, bullying others, and lower risk perception of substance use) and unique predictors (e.g., school achievement on national tests) were identified. These findings may help in planning and conducting preventive interventions to reduce substance use.
Ray, Kimberly L.; Hines, Christina S.; Li, Karl; Dawes, Michael A.; Mathias, Charles W.; Dougherty, Donald M.; Laird, Angela R.
Background. Adolescent marijuana use is associated with structural and functional differences in forebrain regions while performing memory and attention tasks. In the present study, we investigated neural processing in adolescent marijuana users experiencing rewards and losses. Fourteen adolescents with frequent marijuana use (>5 uses per week) and 14 nonuser controls performed a computer task where they were required to guess the outcome of a simulated coin flip while undergoing magnetic resonance imaging. Results. Across all participants, “Wins” and “Losses” were associated with activations including cingulate, middle frontal, superior frontal, and inferior frontal gyri and declive activations. Relative to controls, users had greater activity in the middle and inferior frontal gyri, caudate, and claustrum during “Wins” and greater activity in the anterior and posterior cingulate, middle frontal gyrus, insula, claustrum, and declive during “Losses.” Effective connectivity analyses revealed similar overall network interactions among these regions for users and controls during both “Wins” and “Losses.” However, users and controls had significantly different causal interactions for 10 out of 28 individual paths during the “Losses” condition. Conclusions. Collectively, these results indicate adolescent marijuana users have enhanced neural responses to simulated monetary rewards and losses and relatively subtle differences in effective connectivity. PMID:25692068
Jones, Connor B; Hill, Melanie L; Pardini, Dustin A; Meier, Madeline H
Vaping nicotine (i.e., the use of e-cigarettes and similar devices to inhale nicotine) is becoming increasingly popular among young people. Though some vaporizers are capable of vaporizing cannabis, sparse research has investigated this method of cannabis administration. The present study examines the prevalence and correlates of vaping cannabis in a sample of 482 college students. Participants reported high lifetime rates of vaping nicotine (37%) and cannabis (29%). Men (rs = 0.09, p = .047) and individuals from higher socioeconomic status families (rs = 0.14, p = .003) vaped cannabis more frequently than women and individuals from lower SES families. In addition, those who vaped cannabis more frequently were more open to new experiences (rs = 0.17, p < .001) and showed greater approval of smoking cannabis regularly (rs = 0.35, p < .001). Among the largest correlates of cannabis vaping were frequent cannabis use (rs = 0.70, p < .001) and nicotine vaping (rs = 0.46, p < .001), suggesting that availability of cannabis and vaporizers is particularly important. Participants' top reason for vaping cannabis, endorsed by 65% of those who had vaped cannabis, was convenience and discreetness for use in public places. Several correlates distinguished cannabis users who vaped from cannabis users who did not vape, most notably more frequent cannabis use (odds ratios [OR] = 3.68, p < .001), alcohol use (OR = 2.07, p < .001), nicotine vaping (OR = 1.73, p < .001), and greater approval of smoking cannabis regularly (OR = 2.15, p < .001). Findings suggest that cannabis vaping is prevalent among young adults, particularly among those who use other substances frequently and have more favorable attitudes toward smoking cannabis. Research is needed on the antecedents and potential harms and benefits of cannabis vaping in young adulthood. (PsycINFO Database Record
Arbour-Nicitopoulos, Kelly P.
The study aims were to examine (i) adolescents' attitudes towards family members who use a wheelchair in relation to other health problems and conditions, and (ii) the association between perceived wheelchair stigma and socio-demographic factors. Data were based on surveys from 2790 seventh to 12th grade students derived from the 2007 cycle of the…
Whitt, Ahmed; Garland, Eric L; Howard, Matthew O
Although helium-related fatalities and concerns about potentially harmful effects of helium use have increased in recent years, virtually nothing is known about the epidemiology of helium inhalation in adolescents. This exploratory investigation examined the prevalence and correlates of helium inhalation in a large sample of at-risk youth. Study participants were 723 Missouri adolescents (M age = 15.5, SD = 1.2) in residential treatment for delinquent behavior. More than one-in-nine (N = 81, 11.5%) adolescents had inhaled helium with the intention of getting high, and one-third (N = 27, 34.2%) of helium users reported they actually did get high when they inhaled helium. Helium users were significantly more likely to be Caucasian, to live in rural/small town areas, and to have histories of mental illness, auditory hallucinations, and alcohol and marijuana use than nonusers. Helium users also reported significantly more current psychiatric distress, suicidality, traumatic life experiences, and antisocial attitudes, traits, and behaviors than nonusers. Helium inhalation was prevalent in this sample and many such users reported getting high while using helium. Helium users had psychosocial profiles similar to those of volatile solvent users, suggesting that they may be at substantial risk for a variety of adverse health outcomes.
Hecimovic, Karen; Barrett, Sean P; Darredeau, Christine; Stewart, Sherry H
According to the model of substance abuse of Conrod, Pihl, Stewart, and Dongier (2000), four personality factors (i.e., anxiety sensitivity [AS], introversion/hopelessness [I/H], sensation seeking [SS], and impulsivity [IMP]) are associated with elevated risk for substance use/misuse, with each personality factor being related to preference for particular drugs of abuse (e.g., AS with anxiolytics). However, cannabis use has not been consistently linked to any one of these personality factors. This may be due to the heterogeneity in cannabis use motives. The present study explored the association between these four personality risk factors and different cannabis use motives. Cannabis users completed an interview about their motives for cannabis use as well as the self-report Substance Use Risk Profile Scale (SURPS; Woicik, Conrod, Stewart, & Pihl, 2009), which measures the four personality risk factors. Results showed that AS was associated with conformity motives and I/H was associated with coping motives for cannabis use. SS was positively associated with expansion motives and IMP was associated with drug availability motives. Thus, personality risk factors in the model of Conrod et al. (2000) are associated with distinct cannabis use motives in a pattern consistent with theory.
Andreou, Eleni; Svoli, Hionia
This study examined how internet users' psychological characteristics, amount of internet use and demographic factors contribute to particular dimensions of internet addiction. The sample consisted of 384 adolescents, ranging in age from 15 to 18 years. Participants were asked to complete the Internet Addiction Test (IAT), measures of Locus of…
Morgan, C J A; Freeman, T P; Powell, J; Curran, H V
Smoking cannabis daily doubles an individual's risk of developing a psychotic disorder, yet indicators of specific vulnerability have proved largely elusive. Genetic variation is one potential risk modifier. Single-nucleotide polymorphisms in the AKT1 and catechol-O-methyltransferase (COMT) genes have been implicated in the interaction between cannabis, psychosis and cognition, but no studies have examined their impact on an individual's acute response to smoked cannabis. A total 442 healthy young cannabis users were tested while intoxicated with their own cannabis—which was analysed for delta-9-tetrahydrocannbinol (THC) and cannabidiol content—and also ±7 days apart when drug-free. Psychotomimetic symptoms and working memory were assessed on both the sessions. Variation at the rs2494732 locus of the AKT1 gene predicted acute psychotic response to cannabis along with dependence on the drug and baseline schizotypal symptoms. Working memory following cannabis acutely was worse in females, with some suggestion of an impact of COMT polymorphism on working memory when drug-free. These findings are the first to demonstrate that AKT1 mediates the acute response to cannabis in otherwise healthy individuals and implicate the AKT1 pathway as a possible target for prevention and treatment of cannabis psychosis. PMID:26882038
Odell, Morris S; Frei, Matthew Y; Gerostamoulos, Dimitri; Chu, Mark; Lubman, Dan I
An understanding of tetrahydrocannabinol (THC) kinetics and residual levels after cannabis use is essential in interpreting toxicology tests in body fluids from live subjects, particularly when used in forensic settings for drug abuse, traffic and interpersonal violence cases. However the current literature is largely based on laboratory studies using controlled cannabis dosages in experienced users, with limited research investigating the kinetics of residual THC concentrations in regular high dose cannabis users. Twenty-one dependent cannabis users were recruited at admission to two residential detoxification units in Melbourne, Australia. After being provided with information about, and consenting to, the study, subjects volunteered to provide once-daily blood, urine and oral fluid (saliva) samples for seven consecutive days following admission, involving cessation and abstinence from all cannabis use. Blood and oral fluid specimens were analysed for THC and urine specimens for the metabolite THC-COOH. In some subjects THC was detectable in blood for at least 7 days and oral fluid specimens were positive for THC up to 78 h after admission to the unit. Urinary THC-COOH concentrations exceeded 1000 ng/mL for some subjects 129 h after last use. The presented blood THC levels are higher and persist longer in some individuals than previously described, our understanding and interpretation of THC levels in long term heavy cannabis users may need to be reconsidered.
Achieving Cannabis Cessation - Evaluating N-acetylcysteine Treatment (ACCENT): Design and implementation of a multi-site, randomized controlled study in the National Institute on Drug Abuse Clinical Trials Network
McClure, Erin A.; Sonne, Susan C.; Winhusen, Theresa; Carroll, Kathleen M.; Ghitza, Udi E.; McRae-Clark, Aimee L.; Matthews, Abigail G.; Sharma, Gaurav; Van Veldhuisen, Paul; Vandrey, Ryan G.; Levin, Frances R.; Weiss, Roger D.; Lindblad, Robert; Allen, Colleen; Mooney, Larissa J.; Haynes, Louise; Brigham, Gregory S.; Sparenborg, Steve; Hasson, Albert L.; Gray, Kevin M.
Despite recent advances in behavioral interventions for cannabis use disorders, effect sizes remain modest, and few individuals achieve long-term abstinence. One strategy to enhance outcomes is the addition of pharmacotherapy to complement behavioral treatment, but to date no efficacious medications targeting cannabis use disorders in adults through large, randomized controlled trials have been identified. The National Institute on Drug Abuse Clinical Trials Network (NIDA CTN) is currently conducting a study to test the efficacy of N-acetylcysteine (NAC) versus placebo (PBO), added to contingency management, for cannabis cessation in adults (ages 18–50). This study was designed to replicate positive findings from a study in cannabis-dependent adolescents that found greater odds of abstinence with NAC compared to PBO. This paper describes the design and implementation of an ongoing 12-week, intent-to-treat, double-blind, randomized, placebo-controlled study with one follow-up visit four weeks post-treatment. Approximately 300 treatment-seeking cannabis-dependent adults will be randomized to NAC or PBO across six study sites in the United States. The primary objective of this 12-week study is to evaluate the efficacy of twice-daily orally-administered NAC (1200 mg) versus matched PBO, added to contingency management, on cannabis abstinence. NAC is among the first medications to demonstrate increased odds of abstinence in a randomized controlled study among cannabis users in any age group. The current study will assess the cannabis cessation efficacy of NAC combined with a behavioral intervention in adults, providing a novel and timely contribution to the evidence base for the treatment of cannabis use disorders. PMID:25179587
Farris, Samantha G; Metrik, Jane
Distress intolerance (an individual's perceived or actual inability to tolerate distressing psychological or physiological states) is associated with cannabis use. It is unknown whether a biobehavioral index of distress intolerance, breath-holding duration, is acutely influenced (increased or decreased) by cannabis. Such information may further inform understanding of the expression of psychological or physiological distress postcannabis use. This within-subjects study examined whether smoked marijuana with 2.7%-3.0% delta-9-tetrahydrocannabinol (THC), relative to placebo, acutely changed duration of breath holding. Participants (n = 88; 65.9% male) were nontreatment-seeking frequent cannabis users who smoked placebo or active THC cigarette on two separate study days and completed a breath-holding task postsmoking. Controlling for baseline breath-holding duration and participant sex, THC produced significantly shorter breath-holding durations relative to placebo. There was a significant interaction of drug administration × frequency of cannabis use, such that THC decreased breath-holding time among less frequent but not among more frequent users. Findings indicate that cannabis may exacerbate distress intolerance (via shorter breath-holding durations). As compared to less frequent cannabis users, frequent users display tolerance to cannabis' acute effects including increased ability to tolerate respiratory distress when holding breath. Objective measures of distress intolerance are sensitive to contextual factors such as acute drug intoxication, and may inform the link between cannabis use and the expression of psychological distress. (PsycINFO Database Record
Cho, C M; Hirsch, R; Johnstone, S
Cannabis, commonly known as marijuana, is the most frequently used illicit drug in Australia. Therefore, oral health care providers are likely to encounter patients who are regular users. An upward trend in cannabis use is occurring in Australia, with 40 per cent of the population aged 14 and above having used the drug. There are three main forms of cannabis: marijuana, hash and hash oil, all of which contain the main psychoactive constituent delta-9-tetrahydrocannabinol (THC). Cannabis is most commonly smoked, however it can be added to foods. THC from cannabis enters the bloodstream and exerts its effects on the body via interaction with endogenous receptors. Cannabis affects almost every system of the body, particularly the cardiovascular, respiratory and immune systems. It also has acute and chronic effects on the mental health of some users. Therefore, chronic abuse is a concern because of its negative effects on general physical and mental health. Cannabis abusers generally have poorer oral health than non-users, with an increased risk of dental caries and periodontal diseases. Cannabis smoke acts as a carcinogen and is associated with dysplastic changes and pre-malignant lesions within the oral mucosa. Users are also prone to oral infections, possibly due to the immunosuppressive effects. Dental treatment on patients intoxicated on cannabis can result in the patient experiencing acute anxiety, dysphoria and psychotic-like paranoiac thoughts. The use of local anaesthetic containing epinephrine may seriously prolong tachycardia already induced by an acute dose of cannabis. Oral health care providers should be aware of the diverse adverse effects of cannabis on general and oral health and incorporate questions about patients' patterns of use in the medical history.
Power, R A; Verweij, K J H; Zuhair, M; Montgomery, G W; Henders, A K; Heath, A C; Madden, P A F; Medland, S E; Wray, N R; Martin, N G
Cannabis is the most commonly used illicit drug worldwide. With debate surrounding the legalization and control of use, investigating its health risks has become a pressing area of research. One established association is that between cannabis use and schizophrenia, a debilitating psychiatric disorder affecting ~1% of the population over their lifetime. Although considerable evidence implicates cannabis use as a component cause of schizophrenia, it remains unclear whether this is entirely due to cannabis directly raising risk of psychosis, or whether the same genes that increases psychosis risk may also increase risk of cannabis use. In a sample of 2082 healthy individuals, we show an association between an individual's burden of schizophrenia risk alleles and use of cannabis. This was significant both for comparing those who have ever versus never used cannabis (P=2.6 × 10(-4)), and for quantity of use within users (P=3.0 × 10(-3)). Although directly predicting only a small amount of the variance in cannabis use, these findings suggest that part of the association between schizophrenia and cannabis is due to a shared genetic aetiology. This form of gene-environment correlation is an important consideration when calculating the impact of environmental risk factors, including cannabis use.
Di Forti, Marta; Morgan, Craig; Dazzan, Paola; Pariante, Carmine; Mondelli, Valeria; Marques, Tiago Reis; Handley, Rowena; Luzi, Sonija; Russo, Manuela; Paparelli, Alessandra; Butt, Alexander; Stilo, Simona A.; Wiffen, Ben; Powell, John; Murray, Robin M.
Background People who use cannabis have an increased risk of psychosis, an effect attributed to the active ingredient Δ9-tetrahydrocannabinol (Δ9-THC). There has recently been concern over an increase in the concentration of Δ9-THC in the cannabis available in many countries. Aims To investigate whether people with a first episode of psychosis were particularly likely to use high-potency cannabis. Method We collected information on cannabis use from 280 cases presenting with a first episode of psychosis to the South London & Maudsley National Health Service (NHS) Foundation Trust, and from 174 healthy controls recruited from the local population. Results There was no significant difference between cases and controls in whether they had ever taken cannabis, or age at first use. However, those in the cases group were more likely to be current daily users (OR = 6.4) and to have smoked cannabis for more than 5 years (OR = 2.1). Among those who used cannabis, 78% of the cases group used high-potency cannabis (sinsemilla, ‘skunk’) compared with 37% of the control group (OR 6.8). Conclusions The finding that people with a first episode of psychosis had smoked higher-potency cannabis, for longer and with greater frequency, than a healthy control group is consistent with the hypothesis that Δ9-THC is the active ingredient increasing risk of psychosis. This has important public health implications, given the increased availability and use of high-potency cannabis. PMID:19949195
Henquet, Cécile; Di Forti, Marta; Morrison, Paul; Kuepper, Rebecca; Murray, Robin M
Cannabis use is considered a contributory cause of schizophrenia and psychotic illness. However, only a small proportion of cannabis users develop psychosis. This can partly be explained by the amount and duration of the consumption of cannabis and by its strength but also by the age at which individuals are first exposed to cannabis. Genetic factors, in particular, are likely to play a role in the short- and the long-term effects cannabis may have on psychosis outcome. This review will therefore consider the interplay between genes and exposure to cannabis in the development of psychotic symptoms and schizophrenia. Studies using genetic, epidemiological, experimental, and observational techniques will be discussed to investigate gene-environment correlation gene-environment interaction, and higher order interactions within the cannabis-psychosis association. Evidence suggests that mechanisms of gene-environment interaction are likely to underlie the association between cannabis and psychosis. In this respect, multiple variations within multiple genes--rather than single genetic polymorphisms--together with other environmental factors (eg, stress) may interact with cannabis to increase the risk of psychosis. Further research on these higher order interactions is needed to better understand the biological pathway by which cannabis use, in some individuals, may cause psychosis in the short- and long term.
Vindenes, Vigdis; Strand, Dag Helge; Kristoffersen, Lena; Boix, Fernando; Mørland, Jørg
The main psychoactive substance, Δ9-tetrahydrocannabinol (THC) can be present in highly variable amounts in different cannabis preparations. An increase in THC content in cannabis products has been suggested, and reported from several countries. However, it has not yet been investigated if products with high potency lead to increased human exposure, and thus to higher risk of adverse effects. In this study, we examined the mean concentrations of THC in whole blood samples from drivers apprehended in Norway in the period between 2000 and 2010 suspected of driving under the influence of drugs. Cases with only THC (n=1747) have been compared to cases with only ethanol (n=38796) or amphetamines (n=2493). The increase in mean THC concentration measured from 2000 to 2010 was from 4.0 ± 0.3 to 6.6 ± 0.4 ng/ml (58%), compared to 3% for ethanol and 16% for the amphetamines. This increase in THC concentrations was to some extent paralleled by an increase in the percentage of drivers which were judged as lightly impaired by a physician. Monitoring concentrations of drugs of abuse in blood from apprehended drivers indicated an increasing exposure to THC in Norway. If similar trends are observed globally, it should be further explored if this type of information could be used to elucidate the drug consumption patterns in a population and accordingly the consequences with regard to adverse effects of cannabis from a public health perspective.
Scholes-Balog, Kirsty E.; Hemphill, Sheryl A.; Patton, George C.; Toumbourou, John W.
The current study documents the changing rates of cannabis use, misuse and cannabis-related social harms among Australian adolescents as they grow into young adulthood. It utilised data from a longitudinal study of young people at ages 15, 16, 17, and 19. The rates of cannabis use were found to increase as participants aged; past year use…
Battistella, Giovanni; Fornari, Eleonora; Annoni, Jean-Marie; Chtioui, Haithem; Dao, Kim; Fabritius, Marie; Favrat, Bernard; Mall, Jean-Frédéric; Maeder, Philippe; Giroud, Christian
The dose-dependent toxicity of the main psychoactive component of cannabis in brain regions rich in cannabinoid CB1 receptors is well known in animal studies. However, research in humans does not show common findings across studies regarding the brain regions that are affected after long-term exposure to cannabis. In the present study, we investigate (using Voxel-based Morphometry) gray matter changes in a group of regular cannabis smokers in comparison with a group of occasional smokers matched by the years of cannabis use. We provide evidence that regular cannabis use is associated with gray matter volume reduction in the medial temporal cortex, temporal pole, parahippocampal gyrus, insula, and orbitofrontal cortex; these regions are rich in cannabinoid CB1 receptors and functionally associated with motivational, emotional, and affective processing. Furthermore, these changes correlate with the frequency of cannabis use in the 3 months before inclusion in the study. The age of onset of drug use also influences the magnitude of these changes. Significant gray matter volume reduction could result either from heavy consumption unrelated to the age of onset or instead from recreational cannabis use initiated at an adolescent age. In contrast, the larger gray matter volume detected in the cerebellum of regular smokers without any correlation with the monthly consumption of cannabis may be related to developmental (ontogenic) processes that occur in adolescence.
Liu, Sherry T.; Nemeth, Julianna M.; Klein, Elizabeth G.; Ferketich, Amy K.; Kwan, Mei-Po; Wewers, Mary Ellen
The recent growth in smokeless tobacco (ST) consumption has raised questions about consumer risk perceptions of ST products, especially in high-risk vulnerable populations. This qualitative study examined risk perceptions of ST among adolescent and adult users and non-users in Ohio Appalachia. Focus groups and interviews were held with adolescents (n=53; mean age of 17 years) and adults (n=63; mean age of 34 years) from four Ohio Appalachian counties. Participants were asked about their perceptions of ST-related health risks, ST safety, and the relative safety of ST compared to cigarettes. Transcriptions were coded independently by two individuals. Overall, participants were knowledgeable about health problems from ST use (e.g., oral cancers, periodontal disease). Nearly all participants stated that ST use is not safe; however, there was disagreement about its relative safety. Some perceived all tobacco products as equally harmful; others believed that ST is safer than cigarettes for either the user or those around the user. Disagreements about ST relative safety may reflect mixed public health messages concerning the safety of ST. Comprehensive consumer messages about the relative safety of ST compared to cigarettes are needed. Messages should address the effect of ST on the health of the user as well as those exposed to the user. PMID:25832126
Li, Kong M.; Arnold, Jonathon C.; McGregor, Iain S.
Recent analysis of the cannabinoid content of cannabis plants suggests a shift towards use of high potency plant material with high levels of Δ9-tetrahydrocannabinol (THC) and low levels of other phytocannabinoids, particularly cannabidiol (CBD). Use of this type of cannabis is thought by some to predispose to greater adverse outcomes on mental health and fewer therapeutic benefits. Australia has one of the highest per capita rates of cannabis use in the world yet there has been no previous systematic analysis of the cannabis being used. In the present study we examined the cannabinoid content of 206 cannabis samples that had been confiscated by police from recreational users holding 15 g of cannabis or less, under the New South Wales “Cannabis Cautioning” scheme. A further 26 “Known Provenance” samples were analysed that had been seized by police from larger indoor or outdoor cultivation sites rather than from street level users. An HPLC method was used to determine the content of 9 cannabinoids: THC, CBD, cannabigerol (CBG), and their plant-based carboxylic acid precursors THC-A, CBD-A and CBG-A, as well as cannabichromene (CBC), cannabinol (CBN) and tetrahydrocannabivarin (THC-V). The “Cannabis Cautioning” samples showed high mean THC content (THC+THC-A = 14.88%) and low mean CBD content (CBD+CBD-A = 0.14%). A modest level of CBG was detected (CBG+CBG-A = 1.18%) and very low levels of CBC, CBN and THC-V (<0.1%). “Known Provenance” samples showed no significant differences in THC content between those seized from indoor versus outdoor cultivation sites. The present analysis echoes trends reported in other countries towards the use of high potency cannabis with very low CBD content. The implications for public health outcomes and harm reduction strategies are discussed. PMID:23894589
Swift, Wendy; Wong, Alex; Li, Kong M; Arnold, Jonathon C; McGregor, Iain S
Recent analysis of the cannabinoid content of cannabis plants suggests a shift towards use of high potency plant material with high levels of Δ(9)-tetrahydrocannabinol (THC) and low levels of other phytocannabinoids, particularly cannabidiol (CBD). Use of this type of cannabis is thought by some to predispose to greater adverse outcomes on mental health and fewer therapeutic benefits. Australia has one of the highest per capita rates of cannabis use in the world yet there has been no previous systematic analysis of the cannabis being used. In the present study we examined the cannabinoid content of 206 cannabis samples that had been confiscated by police from recreational users holding 15 g of cannabis or less, under the New South Wales "Cannabis Cautioning" scheme. A further 26 "Known Provenance" samples were analysed that had been seized by police from larger indoor or outdoor cultivation sites rather than from street level users. An HPLC method was used to determine the content of 9 cannabinoids: THC, CBD, cannabigerol (CBG), and their plant-based carboxylic acid precursors THC-A, CBD-A and CBG-A, as well as cannabichromene (CBC), cannabinol (CBN) and tetrahydrocannabivarin (THC-V). The "Cannabis Cautioning" samples showed high mean THC content (THC+THC-A = 14.88%) and low mean CBD content (CBD+CBD-A = 0.14%). A modest level of CBG was detected (CBG+CBG-A = 1.18%) and very low levels of CBC, CBN and THC-V (<0.1%). "Known Provenance" samples showed no significant differences in THC content between those seized from indoor versus outdoor cultivation sites. The present analysis echoes trends reported in other countries towards the use of high potency cannabis with very low CBD content. The implications for public health outcomes and harm reduction strategies are discussed.
Mané, Anna; Fernández-Expósito, Miguel; Bergé, Daniel; Gómez-Pérez, Laura; Sabaté, Agnés; Toll, Alba; Diaz, Laura; Diez-Aja, Cristobal; Perez, Victor
The mechanism underneath the relationship between cannabis and psychosis remains controversial, for which several hypotheses have been proposed, including cannabis as self-medication and cannabis as a risk for the development of psychosis. The aim of this work was to study the relationship between cannabis and psychosis in first-episode psychosis cannabis users and non-users, and non-psychotic cannabis users. The age at the first psychotic episode, duration of untreated psychosis, psychopathology and reasons for cannabis use were assessed. First-episode psychosis cannabis users showed an earlier age at psychosis onset than non-user patients. No significant differences in symptomatology were found. The distinguishing reasons to use cannabis for patients with first-episode psychosis with respect to non-psychotic users were to arrange their thoughts and deal with hallucinations and suspiciousness. These findings are in agreement with both hypotheses: self-medication and secondary psychosis hypothesis. However, longitudinal prospective cohort studies assessing reasons for cannabis use are needed to investigate both hypotheses and their complementarity.
Maremmani, Icro; Lazzeri, Antonio; Pacini, Matteo; Lovrecic, Mercedes; Placidi, Gian Franco; Perugi, Giulio
The prevalence and the clinical meaning of cannabis use in patients with chronic psychosis has not been systematically explored. The authors have compared the diagnostic and symptomatological characteristics of 111 male patients affected by chronic psychosis with and without past or current use of cannabis. Sixty-six patients were still using or had used cannabis; in all cases the use preceded the onset of psychotic symptoms. Forty-three patients were cannabis-positive on urinary screening at the moment of hospitalization and 23 were currently cannabis-free but reported the use of cannabis in the past. Forty-five patients were negative on urinary screening and reported no past history of cannabis use. In evaluating the psychopathological features, the Brief Psychiatric Rating Scale (BPRS) and the Overt Aggression Rating Scale (AORS) were used. The three groups showed similar demographic data, except for age, which was lower in current cannabis users than in nonusers; no differences were found between current and past users. As regards diagnostic features, "mood cluster" was significantly better represented in cannabis users and "schizophrenic cluster" in nonusers; bipolar spectrum disorders were more frequently reported than unipolar ones. When past and current users were grouped together, only blunted affect score was significantly higher in nonusers than in users, while clastic violence showed higher scores in users. These data indicate that chronic, psychosis, whether associated with past or with current use of cannabis, is frequently associated with bipolar spectrum disorders and tends to display less blunted affect and more clastic behavior.
Hindocha, Chandni; Freeman, Tom P; Schafer, Grainne; Gardener, Chelsea; Das, Ravi K; Morgan, Celia J A; Curran, H Valerie
Acute administration of the primary psychoactive constituent of cannabis, Δ-9-tetrahydrocannabinol (THC), impairs human facial affect recognition, implicating the endocannabinoid system in emotional processing. Another main constituent of cannabis, cannabidiol (CBD), has seemingly opposite functional effects on the brain. This study aimed to determine the effects of THC and CBD, both alone and in combination on emotional facial affect recognition. 48 volunteers, selected for high and low frequency of cannabis use and schizotypy, were administered, THC (8mg), CBD (16mg), THC+CBD (8mg+16mg) and placebo, by inhalation, in a 4-way, double-blind, placebo-controlled crossover design. They completed an emotional facial affect recognition task including fearful, angry, happy, sad, surprise and disgust faces varying in intensity from 20% to 100%. A visual analogue scale (VAS) of feeling 'stoned' was also completed. In comparison to placebo, CBD improved emotional facial affect recognition at 60% emotional intensity; THC was detrimental to the recognition of ambiguous faces of 40% intensity. The combination of THC+CBD produced no impairment. Relative to placebo, both THC alone and combined THC+CBD equally increased feelings of being 'stoned'. CBD did not influence feelings of 'stoned'. No effects of frequency of use or schizotypy were found. In conclusion, CBD improves recognition of emotional facial affect and attenuates the impairment induced by THC. This is the first human study examining the effects of different cannabinoids on emotional processing. It provides preliminary evidence that different pharmacological agents acting upon the endocannabinoid system can both improve and impair recognition of emotional faces.
Hindocha, Chandni; Freeman, Tom P.; Schafer, Grainne; Gardener, Chelsea; Das, Ravi K.; Morgan, Celia J.A.; Curran, H. Valerie
Acute administration of the primary psychoactive constituent of cannabis, Δ-9-tetrahydrocannabinol (THC), impairs human facial affect recognition, implicating the endocannabinoid system in emotional processing. Another main constituent of cannabis, cannabidiol (CBD), has seemingly opposite functional effects on the brain. This study aimed to determine the effects of THC and CBD, both alone and in combination on emotional facial affect recognition. 48 volunteers, selected for high and low frequency of cannabis use and schizotypy, were administered, THC (8 mg), CBD (16 mg), THC+CBD (8 mg+16 mg) and placebo, by inhalation, in a 4-way, double-blind, placebo-controlled crossover design. They completed an emotional facial affect recognition task including fearful, angry, happy, sad, surprise and disgust faces varying in intensity from 20% to 100%. A visual analogue scale (VAS) of feeling ‘stoned’ was also completed. In comparison to placebo, CBD improved emotional facial affect recognition at 60% emotional intensity; THC was detrimental to the recognition of ambiguous faces of 40% intensity. The combination of THC+CBD produced no impairment. Relative to placebo, both THC alone and combined THC+CBD equally increased feelings of being ‘stoned’. CBD did not influence feelings of ‘stoned’. No effects of frequency of use or schizotypy were found. In conclusion, CBD improves recognition of emotional facial affect and attenuates the impairment induced by THC. This is the first human study examining the effects of different cannabinoids on emotional processing. It provides preliminary evidence that different pharmacological agents acting upon the endocannabinoid system can both improve and impair recognition of emotional faces. PMID:25534187
Najolia, Gina M; Buckner, Julia D; Cohen, Alex S
Emerging research suggests that cannabis use might be related to psychosis onset in people vulnerable to developing schizophrenia-spectrum disorders. Furthermore, individuals with high-positive and disorganized schizotypy traits report more cannabis use and cannabis-related problems than controls. Social anxiety, a frequently co-occurring schizotypal feature, is related to increased cannabis-related problems in the general population. Building on this research, we explored the impact of social anxiety, measured by the Social Interaction Anxiety Scale (SIAS), and depression and trait anxiety reported on the Brief Symptom Inventory (BSI), on the relationship of schizotypy, measured by the Schizotypy Personality Questionnaire-Brief Revised (SPQ-BR), to cannabis use (n=220 schizotypy, 436 controls) and frequent use and cannabis-related problems among users (n=88 schizotypy, 83 controls) in college undergraduates. Among cannabis users, social anxiety moderated the relationships of schizotypy to frequent cannabis use and more cannabis-related problems in the total schizotypy group, and across high-positive, negative, and disorganized schizotypy subgroups. Depression and trait anxiety also moderated the relationship of schizotypy to frequent cannabis use and more cannabis-related problems, but results varied across high-positive, negative, and disorganized schizotypy subgroups. Results suggest therapeutically targeting negative affective states may be useful in psychosocial intervention for cannabis-related problems in schizotypy.
Nagar, Maayan; Rabinovitz, Sharon
Two studies informed by the terror management health model were conducted to examine the question of how death cognition affects cannabis craving and whether actual cannabis smoking alleviates death cognitions. The first study examined whether priming thoughts of death are associated with subjective cannabis craving among 42 frequent cannabis users randomly assigned to either a mortality salience or control task. When reminded of their death, participants craved cannabis, even though there was no change in their conscious negative mood. The second study examined the effect of cannabis smoking on death cognitions in an exploratory field setting. Fifty frequent cannabis users were randomly assigned to either mortality reminders or control task and completed death-related words accessibility measures before and after smoking cannabis. Results indicate that cannabis served as a buffer and prevented death-related thoughts from entering consciousness, thus acting as a defense mechanism against death anxiety. These findings indicate that death-related concerns may play a hitherto unsuspected role in cannabis craving and consumption. Also discussed are the implications of a terror management perspective in communication of negative health consequences of recreational cannabis smoking and in the use of cannabis for medical purposes among people with terminal illness.
Padula, Claudia B.; McQueeny, Tim; Lisdahl, Krista M.; Price, Jenessa S.; Tapert, Susan F.
Background Amygdala volume abnormalities have been reported in relation to craving in substance-dependent adults, but it remains unclear if these effects are seen in adolescent marijuana (MJ) users, particularly following abstinence. Objectives The aim of this study was to examine the relationship between amygdala volume and craving during 28 days of abstinence in adolescent MJ users. Methods MJ-using adolescents (n = 22) aged 16–19 were recruited as part of a larger study on brain function in teen drug users. Craving measures were collected twice per week throughout a 28-day abstinence period. High-resolution anatomical magnetic resonance imaging data were collected at the end of the 28 days of confirmed abstinence. Left and right amygdala volumes were traced by hand (ICC>0.86). Composite scores for self-reported craving and withdrawal symptoms throughout the 28-day abstinence period were calculated to provide four composite measures of total craving, mood, sleep, and somatic complaints. Results Results revealed that greater craving during abstinence was significantly associated with smaller left and right amygdala volumes, after controlling for age and gender. Other measures of withdrawal, including mood, somatic complaints and sleep problems, were not related to amygdala morphometry. Conclusion These results are consistent with previous findings in adult alcohol-and cocaine-dependent individuals, who demonstrated a relationship between reduced amygdala volumes and increased craving. Future studies are needed to determine if these brain-behavior relationships are attributable to MJ use or predate the onset of substance use. PMID:25668330
Amaral, Gorette; Geierstanger, Sara; Soleimanpour, Samira; Brindis, Claire
Background: The purpose of this study is to compare the mental health risk profile and health utilization behaviors of adolescent school-based health center (SBHC) users and nonusers and discuss the role that SBHCs can play in addressing adolescent health needs. Methods: The sample included 4640 students in grades 9 and 11 who completed the…
Rodrigo, Chaturaka; Rajapakse, Senaka
Cannabis is the most widely used illegitimate substance in the world, and the number of users has increased by 10% over the last decade worldwide. Therefore, it is important to review the evidence on psychoactive properties of cannabis and its possible association with schizophrenia spectrum disorders (SSD). We searched MEDLINE with the key words cannabis and schizophrenia. The search was limited to articles published in English over the last 10 years (1999-2009). Bibliographies of cited literature were also searched. Data sources included reviews published in core clinical journals, cohort studies, interventional studies, case-control studies, cross-sectional analyses and epidemiological data. Results are discussed under 2 topics. Firstly, evidence related to biochemical functioning of cannabinoids and their relationship to endocannabinoid system is discussed briefly. Secondly, the evidence from clinical studies on cannabis, psychosis proneness and SSD are discussed in detail. The discussion is structured to fit in the evidence from results section to 3 plausible hypotheses on cannabis use and SSD. The evidence for and against each hypothesis is discussed. Despite new evidence, the exact relationship between cannabis and SSD is unclear. There is no firm evidence that cannabis causes SSD. The evidence for the argument that schizophrenic patients are attracted to cannabis is also not strong. The most plausible explanation is that cannabis use and psychosis proneness may have synergistic effects in a vulnerable minority. PMID:21938097
Van der Kooy, F; Pomahacova, B; Verpoorte, R
Medicinal cannabis has attracted a lot of attention in recent times. Various forms of administration are used, of which smoking is very common but the least desirable. Smoking cannabis generates a large amount of unwanted side products, of which carcinogenic compounds are the most dangerous. A common practice among recreational drug users, and to a lesser degree patients who uses cannabis as medicine, is to mix the cannabis material with commercially available tobacco in order to increase the burning efficiency of the cigarette and to reduce the overall costs of the cigarette. In this study cannabis material has been mixed with tobacco in order to determine whether tobacco has an influence on the amount of and ratio between tetrahydrocannabinol (THC), cannabigerol (CBG), and cannabinol (CBN) administered while smoking. A small-scale smoking machine has been used and cannabis mixed with various ratios of tobacco was smoked. The trapped smoke was quantitatively analyzed by high-performance liquid chromatography (HPLC) and the amount of THC, CBG, and CBN was determined for each cigarette. We have found that tobacco increases the amount of THC inhaled per gram of cannabis from 32.70 +/- 2.29 mg/g for a 100% cannabis cigarette to 58.90 +/- 2.30 mg/g for a 25% cannabis cigarette. This indicates that tobacco increases the vaporization efficiency of THC by as much as 45% under the conditions tested.
Delmore, T; Kalagian, W F; Loewen, I R
Clients in birth control centers (St. Catharines, Niagara Falls, and Welland) in Ontario, Canada were profiled in 1989; factors affecting compliance with the use of oral contraceptives (OCs) were investigated. Compliance was assessed for those 16 years and after 3 months of OC use. A control group and 2 study groups were randomly formed. 1 group was told about a follow up telephone call if the 3-month checkup appointment was not kept and the other not told. Compliance was determined by keeping the follow-up appointment and taking the pill as directed. Self-administered questionnaires were obtained at the 1st appointment and the 2nd study group was interviewed at the 3-month appointment time. Of the 334 intake interviews, 28.4% were adolescents 16 years old. Information on birth control came most frequently from friends (78.7%; then high school classmates, 61.4% grade school classmates, 61.4%; and family, 38.0%). 94.3% had a boyfriend, primarily a steady one. 82.4% were sexually active before the Center visit. 21.3% had had sex when 15 years old. 9.2% of those sexually active had never used birth control. 85.2% of those using contraception had used a condom at least once, and 33.9% used withdrawal. In the preceding month, birth control was used 60% of the time. 46% of mothers and 25% of fathers were considered supportive of birth control. 228 16 years participated in the compliance study. The 2 study groups and the control group were not significantly different in their compliance. The only statistically significant predictor of compliance (from the intake interview) was the previous use of the condom. Those more likely to be compliant were the 10.9% sexually active who had never used a condom. Continuing with the family doctor, not sexually active, advice to stop, side effects concerns, and remembering to take the pill were the most common reasons for noncompliance. The implication for health and sex education is that emphasis needs to the placed on the risks taken
Kahan, Meldon; Srivastava, Anita; Spithoff, Sheryl; Bromley, Lisa
Objective To offer preliminary guidance on prescribing smoked cannabis for chronic pain before the release of formal guidelines. Quality of evidence We reviewed the literature on the analgesic effectiveness of smoked cannabis and the harms of medical and recreational cannabis use. We developed recommendations on indications, contraindications, precautions, and dosing of smoked cannabis, and categorized the recommendations based on levels of evidence. Evidence is mostly level II (well conducted observational studies) and III (expert opinion). Main message Smoked cannabis might be indicated for patients with severe neuropathic pain conditions who have not responded to adequate trials of pharmaceutical cannabinoids and standard analgesics (level II evidence). Smoked cannabis is contraindicated in patients who are 25 years of age or younger (level II evidence); who have a current, past, or strong family history of psychosis (level II evidence); who have a current or past cannabis use disorder (level III evidence); who have a current substance use disorder (level III evidence); who have cardiovascular or respiratory disease (level III evidence); or who are pregnant or planning to become pregnant (level II evidence). It should be used with caution in patients who smoke tobacco (level II evidence), who are at increased risk of cardiovascular disease (level III evidence), who have anxiety or mood disorders (level II evidence), or who are taking higher doses of opioids or benzodiazepines (level III evidence). Cannabis users should be advised not to drive for at least 3 to 4 hours after smoking, for at least 6 hours after oral ingestion, and for at least 8 hours if they experience a subjective “high” (level II evidence). The maximum recommended dose is 1 inhalation 4 times per day (approximately 400 mg per day) of dried cannabis containing 9% delta-9-tetrahydrocannabinol (level III evidence). Physicians should avoid referring patients to “cannabinoid” clinics (level
Borgelt, Laura M; Franson, Kari L; Nussbaum, Abraham M; Wang, George S
Cannabis, or marijuana, has been used for medicinal purposes for many years. Several types of cannabinoid medicines are available in the United States and Canada. Dronabinol (schedule III), nabilone (schedule II), and nabiximols (not U.S. Food and Drug Administration approved) are cannabis-derived pharmaceuticals. Medical cannabis or medical marijuana, a leafy plant cultivated for the production of its leaves and flowering tops, is a schedule I drug, but patients obtain it through cannabis dispensaries and statewide programs. The effect that cannabinoid compounds have on the cannabinoid receptors (CB(1) and CB(2) ) found in the brain can create varying pharmacologic responses based on formulation and patient characteristics. The cannabinoid Δ(9) -tetrahydrocannabinol has been determined to have the primary psychoactive effects; the effects of several other key cannabinoid compounds have yet to be fully elucidated. Dronabinol and nabilone are indicated for the treatment of nausea and vomiting associated with cancer chemotherapy and of anorexia associated with weight loss in patients with acquired immune deficiency syndrome. However, pain and muscle spasms are the most common reasons that medical cannabis is being recommended. Studies of medical cannabis show significant improvement in various types of pain and muscle spasticity. Reported adverse effects are typically not serious, with the most common being dizziness. Safety concerns regarding cannabis include the increased risk of developing schizophrenia with adolescent use, impairments in memory and cognition, accidental pediatric ingestions, and lack of safety packaging for medical cannabis formulations. This article will describe the pharmacology of cannabis, effects of various dosage formulations, therapeutics benefits and risks of cannabis for pain and muscle spasm, and safety concerns of medical cannabis use.
Gonzalez, Raul; Schuster, Randi M.; Mermelstein, Robin M.; Diviak, Kathleen R.
Background Deficits in decision-making and episodic memory are often reported among heavy cannabis users, yet little is known on how they influence negative consequences from cannabis use. Individual differences in decision-making may explain, in part, why some individuals experience significant problems from their cannabis use whereas others do not. We hypothesized that poor decision-making would moderate relationships between amount of cannabis use and problems from cannabis use whereas episodic memory performance would not. Method Young adult cannabis users (n = 52) with cannabis as their drug of choice and with minimal comorbidities completed semi-structured interviews, self-report questionnaires, and measures of neurocognitive functioning, with decision-making accessed via the Iowa Gambling Task (IGT), episodic memory via the Hopkins Verbal Learning Test – Revised (HVLT) and problems from cannabis use with the Marijuana Problems Scale. Results Strong relationships were observed between amount of cannabis use (lifetime, 12-month, and 30-day) and problems reported from use, but only among participants with Low (impaired) decision-making (R2 = .39 to .51; p < .01). No significant relationships were observed among those with better (low average to high average) decision-making performance (p > .05). In contrast, episodic memory performance was not a significant moderator of the relationship between amount of cannabis use and cannabis problems (p > .05). Conclusions Cannabis users with poor decision-making may be at greater risk for experiencing significant negative consequences from their cannabis use. Our results lend further support to emerging evidence of decision-making as a risk factor for addiction and extend these findings to cannabis users. PMID:26199058
Wilkinson, Samuel T; Radhakrishnan, Rajiv; D'Souza, Deepak Cyril
The link between cannabis use and psychosis comprises three distinct relationships: acute psychosis associated with cannabis intoxication, acute psychosis that lasts beyond the period of acute intoxication, and persistent psychosis not time-locked to exposure. Experimental studies reveal that cannabis, tetrahydrocannabinol (THC) and synthetic cannabinoids reliably produce transient positive, negative, and cognitive symptoms in healthy volunteers. Case-studies indicate that cannabinoids can induce acute psychosis which lasts beyond the period of acute intoxication but resolves within a month. Exposure to cannabis in adolescence is associated with a risk for later psychotic disorder in adulthood; this association is consistent, temporally related, shows a dose-response, and is biologically plausible. However, cannabis is neither necessary nor sufficient to cause a persistent psychotic disorder. More likely it is a component cause that interacts with other factors to result in psychosis. The link between cannabis and psychosis is moderated by age at onset of cannabis use, childhood abuse and genetic vulnerability. While more research is needed to better characterize the relationship between cannabinoid use and the onset and persistence of psychosis, clinicians should be mindful of the potential risk of psychosis especially in vulnerable populations, including adolescents and those with a psychosis diathesis.
Reid, P T; Macleod, J; Robertson, J R
The use of cannabis is embedded within many societies, mostly used by the young and widely perceived to be safe. Increasing concern regarding the potential for cannabis to cause mental health effects has dominated cannabis research and the potential adverse respiratory effects have received relatively little attention. Studies on cannabis are challenging and subject to confounding by concomitant use of tobacco and other social factors, and while many of the studies referred to in this review are beset by the difficulties inherent in undertaking epidemiological research of the effects of cannabis, there is an emerging concern among many chest physicians who would suggest that habitual smoking of cannabis may contribute to the development of chronic obstructive pulmonary disease, pneumothorax and respiratory infections, including tuberculosis. Special attention should be given to the risk of lung cancer, particularly as biological plausibility may precede epidemiology.
Troup, Lucy J; Bastidas, Stephanie; Nguyen, Maia T; Andrzejewski, Jeremy A; Bowers, Matthew; Nomi, Jason S
The effect of cannabis on emotional processing was investigated using event-related potential paradigms (ERPs). ERPs associated with emotional processing of cannabis users, and non-using controls, were recorded and compared during an implicit and explicit emotional expression recognition and empathy task. Comparisons in P3 component mean amplitudes were made between cannabis users and controls. Results showed a significant decrease in the P3 amplitude in cannabis users compared to controls. Specifically, cannabis users showed reduced P3 amplitudes for implicit compared to explicit processing over centro-parietal sites which reversed, and was enhanced, at fronto-central sites. Cannabis users also showed a decreased P3 to happy faces, with an increase to angry faces, compared to controls. These effects appear to increase with those participants that self-reported the highest levels of cannabis consumption. Those cannabis users with the greatest consumption rates showed the largest P3 deficits for explicit processing and negative emotions. These data suggest that there is a complex relationship between cannabis consumption and emotion processing that appears to be modulated by attention.
Troup, Lucy J.; Bastidas, Stephanie; Nguyen, Maia T.; Andrzejewski, Jeremy A.; Bowers, Matthew; Nomi, Jason S.
The effect of cannabis on emotional processing was investigated using event-related potential paradigms (ERPs). ERPs associated with emotional processing of cannabis users, and non-using controls, were recorded and compared during an implicit and explicit emotional expression recognition and empathy task. Comparisons in P3 component mean amplitudes were made between cannabis users and controls. Results showed a significant decrease in the P3 amplitude in cannabis users compared to controls. Specifically, cannabis users showed reduced P3 amplitudes for implicit compared to explicit processing over centro-parietal sites which reversed, and was enhanced, at fronto-central sites. Cannabis users also showed a decreased P3 to happy faces, with an increase to angry faces, compared to controls. These effects appear to increase with those participants that self-reported the highest levels of cannabis consumption. Those cannabis users with the greatest consumption rates showed the largest P3 deficits for explicit processing and negative emotions. These data suggest that there is a complex relationship between cannabis consumption and emotion processing that appears to be modulated by attention. PMID:26926868
Koenig, Kevin T.; Ramos, Mary M.; Fowler, Tara T.; Oreskovich, Kristin; McGrath, Jane; Fairbrother, Gerry
Background: The purpose of this study is to describe patterns of care and service use among adolescent school-based health center (SBHC) users in New Mexico and contrast patterns and services between frequent and infrequent users. Methods: Medical claims/encounter data were analyzed from 59 SBHCs located in secondary schools in New Mexico during…
Schweinsburg, Alecia D.; Nagel, Bonnie J.; Schweinsburg, Brian C.; Park, Ann; Theilmann, Rebecca J.; Tapert, Susan F.
Marijuana is the most widely used illicit substance among teenagers, yet little is known about the possible neural influence of heavy marijuana use during adolescence. We previously demonstrated an altered functional magnetic resonance imaging (fMRI) activity related to spatial working memory (SWM) among adolescents who were heavy users of after an average of 8 days of abstinence, but the persisting neural effects remain unclear. To characterize the potentially persisting neurocognitive effects of heavy marijuana use in adolescence, we examined fMRI response during SWM among abstinent marijuana-using teens. Participants were 15 MJ teens and 17 demographically similar non-using controls, ages 16–18. Teens underwent biweekly urine toxicology screens to ensure abstinence for 28 days before fMRI acquisition. Groups performed similarly on the SWM task, but MJ teens demonstrated lower activity in right dorsolateral prefrontal and occipital cortices, yet significantly more activation in right posterior parietal cortex. MJ teens showed abnormalities in brain response during a SWM task compared with controls, even after 1 month of abstinence. The activation pattern among MJ teens may reflect different patterns of utilization of spatial rehearsal and attention strategies, and could indicate altered neurodevelopment or persisting abnormalities associated with heavy marijuana use in adolescence. PMID:18356027
Psychosis is one of the most serious among the adverse effects associated with cannabis use. The association between cannabis use and psychosis has been variously explored in a series of recent meta-analyses. The results of these meta-analyses show that persons who develop psychosis experience onset of psychosis about 2-3 years earlier if they are cannabis users; this effect is not observed with alcohol or other substance use. Higher levels of cannabis use are associated with greater risk of psychosis. Current cannabis abuse or dependence (but not past use or lower levels of current use) increases the risk of transition into psychosis in persons at ultrahigh risk of psychosis. About a third of patients with first-episode psychosis are cannabis users, and, at follow-up, about half of these users are found to continue their cannabis use. Continued cannabis use (in those who are treated after developing psychosis) is associated with higher risk of relapse into psychosis, and discontinuation of cannabis use reduces the risk of relapse to that in cannabis nonusers. Finally, persons with psychosis who continue to use cannabis have more severe positive symptoms and poorer levels of functioning. Because experimental studies in humans show that cannabinoids and cannabis can induce psychotic symptoms, it is reasonable to assume that the epidemiologic data indicate a causal effect of cannabis in anticipating, triggering, or exacerbating psychosis in vulnerable individuals and in worsening the course and outcome of the illness in those who continue to use the substance. Given the public health implications of these findings, the trend to legalize medical marijuana must be viewed with concern, and efforts are necessary to educate patients and the public about the serious mental and physical health risks associated with cannabis use and abuse.
Norberg, Melissa M.; Battisti, Robert A.; Copeland, Jan; Hermens, Daniel F.; Hickie, Ian B.
The aim of the current study was to delineate the psychiatric profile of cannabis dependent young people (14-29 years old) with mental health problems (N = 36) seeking treatment via a research study. To do so, the Structured Clinical Interview for DSM-IV-TR Axis I Disorders and the Structured Clinical Interview for DSM-IV Childhood Diagnoses were…
Yücel, M; Lorenzetti, V; Suo, C; Zalesky, A; Fornito, A; Takagi, M J; Lubman, D I; Solowij, N
Shifting policies towards legalisation of cannabis for therapeutic and recreational use raise significant ethical issues for health-care providers seeking evidence-based recommendations. We investigated whether heavy cannabis use is associated with persistent harms to the hippocampus, if exposure to cannabidiol offers protection, and whether recovery occurs with abstinence. To do this, we assessed 111 participants: 74 long-term regular cannabis users (with an average of 15.4 years of use) and 37 non-user healthy controls. Cannabis users included subgroups of participants who were either exposed to Δ9-tetrahydrocannabinol (THC) but not to cannabidiol (CBD) or exposed to both, and former users with sustained abstinence. Participants underwent magnetic resonance imaging from which three measures of hippocampal integrity were assessed: (i) volume; (ii) fractional anisotropy; and (iii) N-acetylaspartate (NAA). Three curve-fitting models across the entire sample were tested for each measure to examine whether cannabis-related hippocampal harms are persistent, can be minimised (protected) by exposure to CBD or recovered through long-term abstinence. These analyses supported a protection and recovery model for hippocampal volume (P=0.003) and NAA (P=0.001). Further pairwise analyses showed that cannabis users had smaller hippocampal volumes relative to controls. Users not exposed to CBD had 11% reduced volumes and 15% lower NAA concentrations. Users exposed to CBD and former users did not differ from controls on any measure. Ongoing cannabis use is associated with harms to brain health, underpinned by chronic exposure to THC. However, such harms are minimised by CBD, and can be recovered with extended periods of abstinence. PMID:26756903
Yücel, M; Lorenzetti, V; Suo, C; Zalesky, A; Fornito, A; Takagi, M J; Lubman, D I; Solowij, N
Shifting policies towards legalisation of cannabis for therapeutic and recreational use raise significant ethical issues for health-care providers seeking evidence-based recommendations. We investigated whether heavy cannabis use is associated with persistent harms to the hippocampus, if exposure to cannabidiol offers protection, and whether recovery occurs with abstinence. To do this, we assessed 111 participants: 74 long-term regular cannabis users (with an average of 15.4 years of use) and 37 non-user healthy controls. Cannabis users included subgroups of participants who were either exposed to Δ9-tetrahydrocannabinol (THC) but not to cannabidiol (CBD) or exposed to both, and former users with sustained abstinence. Participants underwent magnetic resonance imaging from which three measures of hippocampal integrity were assessed: (i) volume; (ii) fractional anisotropy; and (iii) N-acetylaspartate (NAA). Three curve-fitting models across the entire sample were tested for each measure to examine whether cannabis-related hippocampal harms are persistent, can be minimised (protected) by exposure to CBD or recovered through long-term abstinence. These analyses supported a protection and recovery model for hippocampal volume (P=0.003) and NAA (P=0.001). Further pairwise analyses showed that cannabis users had smaller hippocampal volumes relative to controls. Users not exposed to CBD had 11% reduced volumes and 15% lower NAA concentrations. Users exposed to CBD and former users did not differ from controls on any measure. Ongoing cannabis use is associated with harms to brain health, underpinned by chronic exposure to THC. However, such harms are minimised by CBD, and can be recovered with extended periods of abstinence.
Hall, Wayne D; Lynskey, Michael
We outline and evaluate competing explanations of three relationships that have consistently been found between cannabis use and the use of other illicit drugs, namely, (1) that cannabis use typically precedes the use of other illicit drugs; and that (2) the earlier cannabis is used, and (3) the more regularly it is used, the more likely a young person is to use other illicit drugs. We consider three major competing explanations of these patterns: (1) that the relationship is due to the fact that there is a shared illicit market for cannabis and other drugs which makes it more likely that other illicit drugs will be used if cannabis is used; (2) that they are explained by the characteristics of those who use cannabis; and (3) that they reflect a causal relationship in which the pharmacological effects of cannabis on brain function increase the likelihood of using other illicit drugs. These explanations are evaluated in the light of evidence from longitudinal epidemiological studies, simulation studies, discordant twin studies and animal studies. The available evidence indicates that the association reflects in part but is not wholly explained by: (1) the selective recruitment to heavy cannabis use of persons with pre-existing traits (that may be in part genetic) that predispose to the use of a variety of different drugs; (2) the affiliation of cannabis users with drug using peers in settings that provide more opportunities to use other illicit drugs at an earlier age; (3) supported by socialisation into an illicit drug subculture with favourable attitudes towards the use of other illicit drugs. Animal studies have raised the possibility that regular cannabis use may have pharmacological effects on brain function that increase the likelihood of using other drugs. We conclude with suggestions for the type of research studies that will enable a decision to be made about the relative contributions that social context, individual characteristics, and drug effects make
Berthet, Aurélie; De Cesare, Mariangela; Favrat, Bernard; Sporkert, Frank; Augsburger, Marc; Thomas, Aurélien; Giroud, Christian
Passive exposure to cannabis smoke may induce effects on behavior and psychomotor skills, and have legal consequences, including the risk of being falsely considered as a cannabis user. This can become a concern, especially in occupational contexts or when driving vehicles. In order to enable a differentiation between a passive and an active exposure to cannabis and to limit the likeliness to be detected positive following passive exposure, this review identified specific biomarkers of passive exposure in urine, blood, oral fluid, hair, and sebum. Out of 958 papers identified on passive exposure to cannabis, 21 were selected. Although positive tests had been observed in all matrices following extremely high passive exposure, some distinctive features were observed in each matrix compared to cannabis active use. More specifically, in everyday life conditions, 11-nor-delta-9-THC-carboxylic acid (THC-COOH) urinary level should be detected below the positivity threshold used to confirm active smoking of cannabis, especially after normalization to creatinine level. Measuring delta-9-tetrahydrocannabinol (THC) and THC-COOH in blood is an appropriate alternative for appraising passive exposure as low and very low concentrations of THC and THC-COOH, respectively, should be measured. In hair, oral fluid (OF) and sweat/sebum emulsion, no THCCOOH should be detected. Its presence in hair argues for regular cannabis consumption and in OF or sweat for recent consumption. The experts should recommend to persons who have to demonstrate abstinence from cannabis to avoid heavily smoky and unventilated environments.
Barrus, Daniel G; Capogrossi, Kristen L; Cates, Sheryl C; Gourdet, Camille K; Peiper, Nicholas C; Novak, Scott P; Lefever, Timothy W; Wiley, Jenny L
Food products containing cannabis extract (edibles) have emerged as a popular and lucrative facet of the legalized market for both recreational and medicinal cannabis. The many formulations of cannabis extracts used in edibles present a unique regulatory challenge for policy makers. Though edibles are often considered a safe, discreet, and effective means of attaining the therapeutic and/or intoxicating effects of cannabis without exposure to the potentially harmful risks of cannabis smoking, little research has evaluated how ingestion differs from other methods of cannabis administration in terms of therapeutic efficacy, subjective effects, and safety. The most prominent difference between ingestion and inhalation of cannabis extracts is the delayed onset of drug effect with ingestion. Consumers often do not understand this aspect of edible use and may consume a greater than intended amount of drug before the drug has taken effect, often resulting in profoundly adverse effects. Written for the educated layperson and for policy makers, this paper explores the current state of research regarding edibles, highlighting the promises and challenges that edibles present to both users and policy makers, and describes the approaches that four states in which recreational cannabis use is legal have taken regarding regulating edibles.
Barrus, Daniel G.; Capogrossi, Kristen L.; Cates, Sheryl C.; Gourdet, Camille K.; Peiper, Nicholas C.; Novak, Scott P.; Lefever, Timothy W.; Wiley, Jenny L.
Food products containing cannabis extract (edibles) have emerged as a popular and lucrative facet of the legalized market for both recreational and medicinal cannabis. The many formulations of cannabis extracts used in edibles present a unique regulatory challenge for policy makers. Though edibles are often considered a safe, discreet, and effective means of attaining the therapeutic and/or intoxicating effects of cannabis without exposure to the potentially harmful risks of cannabis smoking, little research has evaluated how ingestion differs from other methods of cannabis administration in terms of therapeutic efficacy, subjective effects, and safety. The most prominent difference between ingestion and inhalation of cannabis extracts is the delayed onset of drug effect with ingestion. Consumers often do not understand this aspect of edible use and may consume a greater than intended amount of drug before the drug has taken effect, often resulting in profoundly adverse effects. Written for the educated layperson and for policy makers, this paper explores the current state of research regarding edibles, highlighting the promises and challenges that edibles present to both users and policy makers, and describes the approaches that four states in which recreational cannabis use is legal have taken regarding regulating edibles. PMID:28127591
An editorial in this issue describes a cannabis policy framework document issued by a major Canadian research centre, calling for legalization of non-medical use under strict controls to prevent increase in use, especially by adolescents and young adults who are most vulnerable to adverse effects of cannabis. It claims that such a system would eliminate the severe personal, social and monetary costs of prohibition, diminish the illicit market, and provide more humane management of cannabis use disorders. It claims that experience with regulation of alcohol and tobacco will enable a system based on public health principles to control access of youth to cannabis without the harm caused by prohibition. The present critique argues that the claims made against decriminalization and for legalization are unsupported, or even contradicted, by solid evidence. Early experience in other jurisdictions suggests that legalization increases use by adolescents and its attendant harms. Regulation of alcohol use does not provide a good model for cannabis controls because there is widespread alcohol use and harm among adolescents and young adults. Government monopolies of alcohol sale have been used primarily as sources of revenue rather than for guarding public health, and no reason has been offered to believe they would act differently with respect to cannabis. Good policy decisions require extensive unbiased information about the individual and social benefits and costs of both drug use and proposed control measures, and value judgments about the benefit/harm balance of each option. Important parts of the necessary knowledge about cannabis are not yet available, so that the value judgments are not yet possible. Therefore, a better case can be made for eliminating some of the harms of prohibition by decriminalization of cannabis possession and deferring decision about legalization until the necessary knowledge has been acquired.
Raphael, Beverley; Wooding, Sally; Stevens, Garry; Connor, Jason
Cannabis is one of the most commonly used illicit drugs, and its effects have traditionally been seen as less harmful than outcomes associated with the highly prevalent use of alcohol and other illicit substances (e.g., cocaine and amphetamines), and injecting drugs. Consequently, less attention has been focused on developing and evaluating interventions in this area. However, current research supports the idea that cannabis does pose a number of acute and chronic health risks to the individual and to society. The authors review findings concerning the physiological and neurological effects of cannabis, prevalence of use, and studies concerning its possible role as a "gateway" drug. Diagnostic criteria for cannabis dependence and abuse are discussed, with a focus on whether a cannabis withdrawal syndrome exists and if so how it can be diagnosed. There is strong support for a link between cannabis and the development and exacerbation of psychosis and other mental health conditions (e.g., anxiety, depression). Further research is needed to determine the underlying neurochemical processes and their possible contribution to etiology, as well as the social factors that contribute to the increasing use of cannabis by young people. In addition there is a need for systematic evaluation using randomized controlled trials to determine effective prevention and treatment strategies. A number of public health programs that address cannabis use are reviewed along with available evidence for their effectiveness.
Zalesky, Andrew; Solowij, Nadia; Yucel, Murat; Lubman, Dan I.; Takagi, Michael; Harding, Ian H.; Lorenzetti, Valentina; Wang, Ruopeng; Searle, Karissa; Pantelis, Christos; Seal, Marc
Cannabis use typically begins during adolescence and early adulthood, a period when cannabinoid receptors are still abundant in white matter pathways across the brain. However, few studies to date have explored the impact of regular cannabis use on white matter structure, with no previous studies examining its impact on axonal connectivity. The…
Gorman, Dennis M; Charles Huber, J
Medical cannabis is a contentious issue in the United States, with many fearing that introduction of state laws will increase use among the general population. The present study examined whether the introduction of such laws affects the level of cannabis use among arrestees and emergency department patients. Using the Arrestee Drug Abuse Monitoring system, data from adult arrestees for the period 1995-2002 were examined in three cities in California (Los Angeles, San Diego, San Jose), one city in Colorado (Denver), and one city in Oregon (Portland). Data were also analysed for juvenile arrestees in two of the California cities and Portland. Data on emergency department patients from the Drug Abuse Warning Network for the period 1994-2002 were examined in three metropolitan areas in California (Los Angeles, San Diego, San Francisco), one in Colorado (Denver), and one in Washington State (Seattle). The analysis followed an interrupted time-series design. No statistically significant pre-law versus post-law differences were found in any of the ADAM or DAWN sites. Thus, consistent with other studies of the liberalization of cannabis laws, medical cannabis laws do not appear to increase use of the drug. One reason for this might be that relatively few individuals are registered medical cannabis patients or caregivers. In addition, use of the drug by those already sick might "de-glamorise" it and thereby do little to encourage use among others.
Verdejo-García, Antonio J; López-Torrecillas, Francisca; Aguilar de Arcos, Francisco; Pérez-García, Miguel
Executive functioning impairments have been demonstrated following consumption of drugs of abuse. These executive impairments could play an important role on the development of the addictive process and rehabilitation of substance abusers. Recent neuropsychological models of executive functioning assume a multicomponent organization of these processes, suggesting different functions could contribute differentially to performance on executive tasks. The aim of this study was to analyze the relationship between severity of consumption of different drugs and neuropsychological performance on tasks sensitive to impairment in the executive subprocesses of working memory, response inhibition, cognitive flexibility, and abstract reasoning. Instruments sensitive to impairment in these four components were administered to 38 polysubstance abusers along with a severity of drug consumption interview. Multiple regression analyses were used. Results showed a differential impact of severity of MDMA abuse on working memory and abstract reasoning indices, of cocaine severity on an inhibitory control index and of cannabis on a cognitive flexibility index. Metabolic reorganization of monoamine frontal-subcortical pathways after drug exposure are proposed as possible explanations for these impairments.
Schweinsburg, Alecia D.; Schweinsburg, Brian C.; Medina, Krista Lisdahl; McQueeny, Tim; Brown, Sandra A.; Tapert, Susan F.
Some neurocognitive recovery occurs within a month of abstinence from heavy marijuana use, yet functional magnetic resonance imaging (fMRI) has revealed altered activation among recent and abstinent adult users. Here, we compared fMRI response during a spatial working memory (SWM) task between adolescent marijuana users with brief and sustained durations of abstinence. Participants were 13 recent users (2 – 7 days abstinent), 13 abstinent users (27 – 60 days abstinent), and 18 non-using controls, all ages 15 – 18. Groups were similar on demographics, had no psychiatric or medical disorders, and user groups were similar on substance histories. Teens performed a 2-back SWM task during fMRI. Groups performed similarly on the task, but recent users showed greater fMRI response in medial and left superior prefrontal cortices, as well as bilateral insula. Abstinent users had increased response in the right precentral gyrus (clusters ≥1328 μl, p<.05). This cross-sectional study did not examine changes in brain response among the same participants over time. Yet results suggests that adolescents who recently used marijuana show increased brain activity in regions associated with working memory updating and inhibition, compared to users with weeks to months of abstinence. This study preliminarily suggests that (1) recent marijuana use may disrupt neural connections associated with SWM and result in compensatory brain response, and (2) sustained abstinence from marijuana may be associated with improvements in SWM response among adolescents. PMID:21053763
Colizzi, Marco; Iyegbe, Conrad; Powell, John; Ursini, Gianluca; Porcelli, Annamaria; Bonvino, Aurora; Taurisano, Paolo; Romano, Raffaella; Masellis, Rita; Blasi, Giuseppe; Morgan, Craig; Aitchison, Katherine; Mondelli, Valeria; Luzi, Sonija; Kolliakou, Anna; David, Anthony; Murray, Robin M; Bertolino, Alessandro; Di Forti, Marta
Both cannabis use and the dopamine receptor (DRD2) gene have been associated with schizophrenia, psychosis-like experiences, and cognition. However, there are no published data investigating whether genetically determined variation in DRD2 dopaminergic signaling might play a role in individual susceptibility to cannabis-associated psychosis. We genotyped (1) a case-control study of 272 patients with their first episode of psychosis and 234 controls, and also from (2) a sample of 252 healthy subjects, for functional variation in DRD2, rs1076560. Data on history of cannabis use were collected on all the studied subjects by administering the Cannabis Experience Questionnaire. In the healthy subjects' sample, we also collected data on schizotypy and cognitive performance using the Schizotypal Personality Questionnaire and the N-back working memory task. In the case-control study, we found a significant interaction between the rs1076560 DRD2 genotype and cannabis use in influencing the likelihood of a psychotic disorder. Among cannabis users, carriers of the DRD2, rs1076560, T allele showed a 3-fold increased probability to suffer a psychotic disorder compared with GG carriers (OR = 3.07; 95% confidence interval [CI]: 1.22-7.63). Among daily users, T carrying subjects showed a 5-fold increase in the odds of psychosis compared to GG carriers (OR = 4.82; 95% CI: 1.39-16.71). Among the healthy subjects, T carrying cannabis users had increased schizotypy compared with T carrying cannabis-naïve subjects, GG cannabis users, and GG cannabis-naïve subjects (all P ≤ .025). T carrying cannabis users had reduced working memory accuracy compared with the other groups (all P ≤ .008). Thus, variation of the DRD2, rs1076560, genotype may modulate the psychosis-inducing effect of cannabis use.
Järvinen, Margaretha; Ravn, Signe
A considerable part of today's sociological research on recreational drug use is (explicitly or implicitly) inspired by Howard Becker's classical model of deviant careers. The aim of the present paper is to directly apply Becker's theory to empirical data on present-day cannabis use and to suggest a revision of the theory. As part of this, we propose a stretch of the sociological approach represented by Becker and followers in order to include, not only recreational drug use, but also use for which young people have sought treatment. The paper is based on 30 qualitative interviews with young people in treatment for cannabis problems in Copenhagen, Denmark. We suggest a revision of Becker's career model in relation to four aspects: initiation of cannabis use, differentiation between socially integrated and individualised, disintegrated use, social control from non-users, and the users' moral stance on cannabis. A central point of the paper is that social interaction may both motivate cannabis use, as Becker proposed, and serve as a protective factor against extensive, problematic use.
Hindocha, Chandni; Wollenberg, Olivia; Carter Leno, Virginia; Alvarez, Beatriz O; Curran, H Valerie; Freeman, Tom P
Heavy cannabis use is associated with interpersonal problems that may arise in part from the inaccurate perception of emotional faces. Only one study reports impairments in emotional facial affect processing in heavy cannabis users; however, it is not clear whether these findings were attributable to differences between cannabis users and controls in schizotypy or gender, rather than from cannabis use itself. A total of 25 frequent cannabis users and 34 non-using controls completed an emotional processing task in an independent groups design. We asked participants to identify the emotions on faces morphed from neutral to 100% intensity, for six basic emotions. We measured percentage hit rate, sensitivity and response bias. Schizotypy was indexed using the Schizotypal Personality Questionnaire. Cannabis users showed lower accuracy and sensitivity on the emotional recognition task. Gender and schizotypy did not differ between the two groups. Men showed lower accuracy on the emotional processing task, but impairments in cannabis users remained when covarying for gender. Schizotypy negatively correlated with sensitivity scores, but this was unreliable when accounting for the groups. Chronic cannabis users showed generalised impairment in emotional processing. These results appeared as independent of the emotional processing deficits amongst men, and were not related to schizotypy.
Dysterheft, Jennifer L.; Rice, Ian M.; Rice, Laura A.
Ten full-time adolescent wheelchair users (ages 13–18) completed a total of three propulsion trials on carpet and tile surfaces, at a self-selected velocity, and on a concrete surface, at a controlled velocity. All trials were performed in their personal wheelchair with force and moment sensing wheels attached bilaterally. The first two trials on each surface were used as pre-intervention control trials. The third trial was performed after receiving training on proper propulsion technique. Peak resultant force, contact angle, stroke frequency, and velocity were recorded during all trials for primary analysis. Carpet and tile trials resulted in significant increases in contact angle and peak total force with decreased stroke frequency after training. During the velocity controlled trials on concrete, significant increases in contact angle occurred, as well as decreases in stroke frequency after training. Overall, the use of a training video and verbal feedback may help to improve short-term propulsion technique in adolescent wheelchair users and decrease the risk of developing upper limb pain and injury. PMID:26042217
Dysterheft, Jennifer L; Rice, Ian M; Rice, Laura A
Ten full-time adolescent wheelchair users (ages 13-18) completed a total of three propulsion trials on carpet and tile surfaces, at a self-selected velocity, and on a concrete surface, at a controlled velocity. All trials were performed in their personal wheelchair with force and moment sensing wheels attached bilaterally. The first two trials on each surface were used as pre-intervention control trials. The third trial was performed after receiving training on proper propulsion technique. Peak resultant force, contact angle, stroke frequency, and velocity were recorded during all trials for primary analysis. Carpet and tile trials resulted in significant increases in contact angle and peak total force with decreased stroke frequency after training. During the velocity controlled trials on concrete, significant increases in contact angle occurred, as well as decreases in stroke frequency after training. Overall, the use of a training video and verbal feedback may help to improve short-term propulsion technique in adolescent wheelchair users and decrease the risk of developing upper limb pain and injury.
Raynal, Patrick; Chabrol, Henri
The aim of the study was to examine the association of schizotypal and borderline personality traits to cannabis use. Participants were 476 college students (95 males; 381 females; mean age of males=21; mean age of females=20.7) who completed self-report questionnaires assessing cannabis use, schizotypal and borderline personality traits. Problematic cannabis use, depressive symptoms, borderline and schizotypal traits were significantly inter-correlated. A logistic regression analysis showed that only borderline traits contributed significantly to cannabis use in the total sample. A multiple regression analysis showed that only schizotypal traits were positively and uniquely associated to problematic cannabis use symptoms among users. These results may imply that schizotypal traits are not a risk factor for initiating use, but may facilitate the development of problematic use symptoms among users. This study showed the necessity of taking into account schizotypal traits when exploring the relationships between depressive symptoms, borderline traits and cannabis use.
Erkens, J A; Janse, A F C; Herings, R M C
Since September 2003, cannabis is available for medicinal purposes in Dutch pharmacies to. It was anticipated that the medicinal cannabis use via illegal ways would decrease. The objective of this study was to get insight in the use of medicinal cannabis in daily practise as dispensed by community pharmacies and to characterize the users as well as the symptoms and conditions cannabis is prescribed for.A prospective follow-up study among 200 patients who filled a prescription for medicinal cannabis was performed in the period between September 2003 and January 2004. The patients filled out a structured questionnaire concerning symptoms and conditions and their experience with cannabis. Of all patients, 42% suffered from multiple sclerosis, 11% suffered from rheumatic diseases, and 60% of respondents already used cannabis before the legalization. Cannabis was mainly used for chronic pain and muscle cramp/stiffness.The indication of medicinal cannabis use was in accordance with the labeled indications. However, more than 80% of the patients still obtained cannabis for medicinal purpose from the illegal circuit. Because of the higher prices in pharmacies, ongoing debate on the unproven effectiveness of the drug and the hesitation by physicians to prescribe cannabis.
Karila, Laurent; Roux, Perrine; Rolland, Benjamin; Benyamina, Amine; Reynaud, Michel; Aubin, Henri-Jean; Lançon, Christophe
Cannabis remains the most commonly used and trafficked illicit drug in the world. Its use is largely concentrated among young people (15- to 34-year-olds). There is a variety of cannabis use patterns, ranging from experimental use to dependent use. Men are more likely than women to report both early initiation and frequent use of cannabis. Due to the high prevalence of cannabis use, the impact of cannabis on public health may be significant. A range of acute and chronic health problems associated with cannabis use has been identified. Cannabis can frequently have negative effects in its users, which may be amplified by certain demographic and/or psychosocial factors. Acute adverse effects include hyperemesis syndrome, impaired coordination and performance, anxiety, suicidal ideations/tendencies, and psychotic symptoms. Acute cannabis consumption is also associated with an increased risk of motor vehicle crashes, especially fatal collisions. Evidence indicates that frequent and prolonged use of cannabis can be detrimental to both mental and physical health. Chronic effects of cannabis use include mood disorders, exacerbation of psychotic disorders in vulnerable people, cannabis use disorders, withdrawal syndrome, neurocognitive impairments, cardiovascular and respiratory and other diseases.
Morgan, Celia JA; Freeman, Tom P; Schafer, Gráinne L; Curran, H Valerie
Worldwide cannabis dependence is increasing, as is the concentration of Δ9-tetrahydrocannabinol (THC) in street cannabis. At the same time, the concentration of the second most abundant cannabinoid in street cannabis, cannabidiol (CBD), is decreasing. These two cannabinoids have opposing effects both pharmacologically and behaviorally when administered in the laboratory. No research has yet examined how the ratio of these constituents impacts on the appetitive/reinforcing effects of cannabis in humans. A total of 94 cannabis users were tested 7 days apart, once while non-intoxicated and once while acutely under the influence of their own chosen smoked cannabis on dependence-related measures. Using an unprecedented methodology, a sample of cannabis (as well as saliva) was collected from each user and analyzed for levels of cannabinoids. On the basis of CBD : THC ratios in the cannabis, individuals from the top and bottom tertiles were directly compared on indices of the reinforcing effects of drugs, explicit liking, and implicit attentional bias to drug stimuli. When intoxicated, smokers of high CBD : THC strains showed reduced attentional bias to drug and food stimuli compared with smokers of low CBD : THC. Those smoking higher CBD : THC strains also showed lower self-rated liking of cannabis stimuli on both test days. Our findings suggest that CBD has potential as a treatment for cannabis dependence. The acute modulation of the incentive salience of drug cues by CBD may possibly generalize to a treatment for other addictive disorders. PMID:20428110
Chen, Lian-Yu; Crum, Rosa M.; Strain, Eric C.; Martins, Silvia S.; Mojtabai, Ramin
Objectives There are growing concerns about nonmedical use of ADHD stimulants among adolescents; yet, little is known whether there exist heterogeneous subgroups among adolescents with nonmedical ADHD stimulant use according to their concurrent substances use. Methods We used latent class analysis (LCA) to examine patterns of past-year problematic substance use (meeting any criteria for abuse or dependence) in a sample of 2,203 adolescent participants from the National Surveys on Drug Use and Health 2006–2011 who reported past-year nonmedical use of ADHD stimulants. Multivariable latent regression was used to assess the association of socio-demographic characteristics, mental health and behavioral problems with the latent classes. Results The model fit indices favored a four-class model, including a large class with frequent concurrent use of alcohol and marijuana (Alcohol/Marijuana class; 41.2%), a second large class with infrequent use of other substances (Low substance class, 36.3%), a third class characterized by more frequent misuse of prescription drugs as well as other substances (Prescription drug+ class; 14.8%), and finally a class characterized by problematic use of multiple substances (Multiple substance class; 7.7%). Compared with individuals in Low substance class, those in the other three classes were all more likely to report mental health problems, deviant behaviors and substance abuse service use. Conclusions Adolescent nonmedical ADHD stimulants users are a heterogeneous group with distinct classes with regard to concurrent substance use, mental health and behavioral problems. The findings have implications for planning of tailored prevention and treatment programs to curb stimulant use for this age group. PMID:26026384
Ruiz-Veguilla, Miguel; Barrigón, María Luisa; Hernández, Laureano; Rubio, José Luis; Gurpegui, Manuel; Sarramea, Fernando; Cervilla, Jorge; Gutiérrez, Blanca; James, Anthony; Ferrin, Maite
This study aimed to explore the associations between daily cannabis use and the specific profiles of subclinical symptoms in a non-clinical population obtained through snowball sampling, taking into account alcohol use, other drug use, social exclusion and age at onset of cannabis use. We included 85 daily cannabis users and 100 non-daily cannabis users. Both the case and the control populations were identified by snowball sampling. Daily cannabis use was associated with more alcohol intake and other drug use, as well as with early onset in the use of cannabis. Daily cannabis use appeared to exert a dose-response effect on first-rank symptoms, mania symptoms and auditory hallucinations, even after adjusting for sex, age, other drug use, social exclusion and age at onset of cannabis use. The paranoid dimension was only associated with the heaviest consumption of cannabis. Initial age of cannabis use modified the effects of daily cannabis use on the first-rank and voices experiences. Daily cannabis use was associated with significantly more first-rank and voices experiences among those subjects who started to use cannabis before 17 years of age. Our study supports the association of psychotic experiences with cannabis use even among non-psychotic subjects.
Michaels, Timothy I; Novakovic, Vladan
In recent years, increasing popular support for the medicinal and recreational use of cannabis has led to legalization for both medicinal and recreational purposes in the United States. To the extent that these changes in policy lead to increase widespread use, it is important to consider the association between heavy chronic cannabis use and the onset of psychotic illnesses, such as schizophrenia. This article provides a brief review of evidence that support cannabis use as a risk factor in the complex etiology of psychotic illness. In addition to reviewing psychopharmacology, longitudinal research, and clinical studies, the article addresses the potential implications of current research on public health policy.
Stein For The Executive Committee Of The Central Drug Authority, Dan Joseph
There is an ongoing national debate around cannabis policy. This brief position statement by the Executive Committee of the Central Drug Authorityoutlines some of the factors that have contributed to this debate, delineates reduction strategies, summarises the harms and benefits ofmarijuana, and provides recommendations. These recommendations emphasise an integrated and evidence-based approach, the need forresources to implement harm reduction strategies against continued and chronic use of alcohol and cannabis, and the potential value of afocus on decriminalisation rather than the legalisation of cannabis.
Rieder, Michael J
Cannabis is a psychoactive compound with a long history of recreational and therapeutic use. Current considerations regarding cannabis use for medical purposes in children have been stimulated by recent case reports describing its beneficial effect with refractory epilepsy. Overall, there are insufficient data to support either the efficacy or safety of cannabis use for any indications in children, and an increasing body of data suggests possible harm, most importantly in specific conditions. The potential for cannabis as a therapeutic agent must be evaluated carefully for both efficacy and safety in treating specific paediatric health conditions. Smoking is not an acceptable mode of drug delivery for children. The use of cannabis for medical purposes in specific cases should not be construed as a justification for recreational cannabis use by adolescents. Recommendations for therapeutic use in exceptional paediatric cases are offered, always providing that this treatment course is carefully evaluated in individuals and in ongoing, well-designed research studies to determine safety and efficacy.
France holds the record for cannabis use in Europe, especially among adolescents. This drug of abuse is thus mainly used during a very sensitive period of brain development, education, vehicle driving and development of life projects. In addition, synthetic derivatives of tetrahydrocannabinol (THC), which are more noxious than cannabis itself are now appearing on the market. Traficking and cultivation for personnal use have intensified; products proposed for sale are richer in THC; and some methods of consumption (e-cigarettes, vaporizers, water pipes) increase the supply of THC to the lungs and thence to the body and brain. It is in this context that attempts are being made to legalize this drug of abuse. Other attempts are made to disguise it as a medication. Meanwhile, the list of its psychic as well as physical damages grows longer, with some very severe cases of major injuries. This evolution takes place in spite of numerous warnings expressed by the French Academy of Medicine. Subsequently, it is prompted to carefully and vigorously denounce these events. This will be the aim of this thematic session.
Basu, Debasish; Malhotra, Anil; Varma, Vijoy K.
Association between cannabis use and various psychiatric syndromes does exist, but their nature remains elusive. Cannabis intoxication, ‘cannabis psychosis’ and certain other conditions related with cannabis use like flashbacks and prolonged depersonalization are discussed in this paper. The controversial nature of the cannabis - schizophrenia link is noted, and various methodological issues in clinical cannabis research are highlighted. PMID:21743686
Palamar, Joseph J.; Ompad, Danielle C.; Petkova, Eva
Background Support for cannabis (“marijuana”) legalization is increasing in the United States (US). Use was recently legalized in two states and in Uruguay, and other states and countries are expected to follow suit. This study examined intentions to use among US high school seniors if cannabis were to become legally available. Methods Data from the last five cohorts (2007–2011) of high school seniors in Monitoring the Future, an annual nationally representative survey of students in the US were utilized. Data were analyzed separately for the 6,116 seniors who reported no lifetime use of cannabis and the 3,828 seniors who reported lifetime use (weighted Ns). We examined whether demographic characteristics, substance use and perceived friend disapproval towards cannabis use were associated with 1) intention to try cannabis among non-lifetime users, and 2) intention to use cannabis as often or more often among lifetime users, if cannabis was legal to use. Results Ten percent of non-cannabis-using students reported intent to initiate use if legal and this would constitute a 5.6% absolute increase in lifetime prevalence of cannabis use in this age group from 45.6% (95% CI=46.6, 44.6) to 51.2% (95% CI=50.2, 52.2). Eighteen percent of lifetime users reported intent to use cannabis more often if it was legal. Odds for intention to use outcomes increased among groups already at high risk for use (e.g., males, whites, cigarette smokers) and odds were reduced when friends disapproved of use. However, large proportions of subgroups of students normally at low risk for use (e.g., non-cigarette-smokers, religious students, those with friends who disapprove of use) reported intention to use if legal. Recent use was also a risk factor for reporting intention to use as often or more often. Conclusion Prevalence of cannabis use is expected to increase if cannabis is legal to use and legally available. PMID:24589410
Skopp, Gisela; Strohbeck-Kuehner, Peter; Mann, Karl; Hermann, Derik
Hair analysis has shown great potential in the detection and control of drug use. Whether an assay is of quantitative value roughly corresponding to the amount of drug consumed, is still a matter of debate. The present investigation was aimed at a possible relationship between the cannabinoid concentration in hair and the cumulative dose in regular users of cannabis. Hair samples from the vertex region of the scalp were obtained from 12 male regular users of cannabis, and 10 male subjects with no experience of cannabis served as controls. None of the subjects had his hair permed, bleached or colored. Cannabis users provided information on drug use such as the current cannabis dose per day, the cumulative cannabis dose of the last 3 months, as well as the frequency of cannabis use during the last year. The concentration of delta-9-tetrahydrocannabinol (THC), cannabinol (CBN) and cannabidiol (CBD) in hair was determined using gas chromatography-mass spectrometry. Cannabinoids were present in any hair sample of cannabis users, but were not detectable in control specimens. An increase in the amount of cannabinoids in hair with increasing dose was evident. The concentration of major cannabinoids (sum of THC, CBD and CBN) was significantly correlated to either the reported cumulative cannabis dose during the last 3 months or to the cannabis use during the last 3 months estimated from the daily dose and the frequency per year (r=0.68 or 0.71, p=0.023 or 0.014). A significant relationship between THC and the amount of cannabis used could not be established. As a conclusion, the sum of major cannabinoids in hair of regular users may provide a better measure of drug use than THC.
Recent research has clarified a number of important questions concerning adverse effects of cannabis on health. A causal role of acute cannabis intoxication in motor vehicle and other accidents has now been shown by the presence of measurable levels of Delta(9)-tetrahydrocannabinol (THC) in the blood of injured drivers in the absence of alcohol or other drugs, by surveys of driving under the influence of cannabis, and by significantly higher accident culpability risk of drivers using cannabis. Chronic inflammatory and precancerous changes in the airways have been demonstrated in cannabis smokers, and the most recent case-control study shows an increased risk of airways cancer that is proportional to the amount of cannabis use. Several different studies indicate that the epidemiological link between cannabis use and schizophrenia probably represents a causal role of cannabis in precipitating the onset or relapse of schizophrenia. A weaker but significant link between cannabis and depression has been found in various cohort studies, but the nature of the link is not yet clear. A large body of evidence now demonstrates that cannabis dependence, both behavioral and physical, does occur in about 7-10% of regular users, and that early onset of use, and especially of weekly or daily use, is a strong predictor of future dependence. Cognitive impairments of various types are readily demonstrable during acute cannabis intoxication, but there is no suitable evidence yet available to permit a decision as to whether long-lasting or permanent functional losses can result from chronic heavy use in adults. However, a small but growing body of evidence indicates subtle but apparently permanent effects on memory, information processing, and executive functions, in the offspring of women who used cannabis during pregnancy. In total, the evidence indicates that regular heavy use of cannabis carries significant risks for the individual user and for the health care system.
Vandrey, Ryan; Haney, Margaret
Cannabis is the most widely used illicit drug in the world. Treatment admissions for cannabis use disorders have risen considerably in recent years, and the identification of medications that can be used to improve treatment outcomes among this population is a priority for researchers and clinicians. To date, several medications have been investigated for indications of clinically desirable effects among cannabis users (e.g. reduced withdrawal, attenuation of subjective or reinforcing effects, reduced relapse). Medications studied have included those 1) known to be effective in the treatment of other drug use disorders, 2) known to alleviate symptoms of cannabis withdrawal (e.g. dysphoric mood, irritability), or 3) that directly affect endogenous cannabinoid receptor function. Results from controlled laboratory studies and small open-label clinical studies indicate that buspirone, dronabinol, fluoxetine, lithium, lofexedine, and rimonabant may have therapeutic benefit for those seeking treatment for cannabis-related problems. However, controlled clinical trials have not been conducted and are needed to both confirm the potential clinical efficacy of these medications and to validate the laboratory models being used to study candidate medications. While the recent increase in research towards the development of pharmacotherapy for cannabis use disorders has yielded promising leads, the published research conducted to date is not sufficient to support broad clinical use of these medications to treat cannabis-use disorders. PMID:19552483
Hollister, Leo E.
Literature pertaining to the effects of cannabis use and health which has been published during the past 11 years has been reviewed. Many older concerns about adverse effects on health (chromosomal damage, 'cannabinol psychosis', endocrine abnormalities, cardiac events, impaired immunity) no longer seem to elicit much interest. Continuing concerns about the adverse cognitive effects of chronic use indicate that these can be demonstrated by proper testing; some studies suggest that they may be long-lasting. Although cannabis does not produce a specific psychosis, the possibility exists that it may exacerbate schizophrenia in persons predisposed to that disorder. However, evidence from retrospective surveys must always be questioned. Tolerance and dependence have occurred in man, confirming previous findings in many other species. Addiction tends to be mild and is probably less severe than with other social drugs. Driving under the influence of cannabis is impaired acutely; how long such impairments last is still unknown. More exacting tasks, such as flying an airplane, may be impaired for as long as 24 hours. While there is no doubt that marijuana smoke contains carcinogens, an increase in cancer among users has thus far been anecdotal. Because of the long latent period between cancer induction and initiation of cigarette smoking, the full story is yet to be told. Marijuana use during pregnancy is not advised although the consequences are usually not greater than those of smoking cigarettes, and far less than those from alcohol use. Whether smoked marijuana should become a therapeutic agent requires a cost-benefit analysis of the potential benefits versus the adverse effects of such use as we now know them.
Adlaf, Edward M; Mann, Robert E; Paglia, Angela
Little is known about the risk of injury among adolescents who drive after the use of alcohol or cannabis or ride in cars driven by drunk drivers. We examined data from self-administered interviews with 1846 students in grades 7 to 13 who participated in the 2001 Ontario Student Drug Use Survey about their experiences related to alcohol, cannabis and driving during the 12 months preceding the survey. In all, 31.9% of the students reported being a passenger in a car driven by a drunk driver; of the students in grades 10 to 13 who had a driver's licence, 15.1% reported driving within an hour after consuming 2 or more drinks, and 19.7% reported driving within an hour after using cannabis. Our study shows that a sizeable proportion of adolescents are exposed to alcohol- and drug-related driving risks.
Tang, Jie; Yu, Yizhen; Du, Yukai; Ma, Ying; Zhang, Dongying; Wang, Jiaji
Internet addiction (IA) among adolescents is a serious public health problem around the world. However, there have been few studies that examine the association between IA and stressful life events and psychological symptoms among Chinese adolescent internet users. We examined the association between IA and stressful life events and psychological symptoms among a random sample of school students who were internet users (N=755) in Wuhan, China. Internet addiction, stressful life events, coping style and psychological symptoms were measured by self-rated scales. The prevalence rate of internet addiction was 6.0% among adolescent internet users. Logistic regression analyses indicated that stressors from interpersonal problem and school related problem and anxiety symptoms were significantly associated with IA after controlling for demographic characteristics. Analyses examining the coping style with the IA revealed that negative coping style may mediate the effects of stressful life events to increase the risk of IA. However, no significant interaction of stressful life events and psychological symptoms was found. These findings of the current study indicate a high prevalence of internet addiction among Chinese adolescent internet users and highlight the importance of stressors from interpersonal problem and school related problem as a risk factor for IA which mainly mediated through negative coping style.
Strukcinskiene, Birute; Uğur-Baysal, Serpil; Raistenskis, Juozas
This study analyzes traffic mortality trends among road users from 1998 to 2012 in children and adolescents aged 0-19 years in Lithuania. National mortality data of pedestrians, cyclists, motorcyclists, and car occupants were used to compare trend lines. The study revealed that 56% of the deceased in road traffic crashes were car occupants, while 24% were pedestrians. The incidence of death from traffic injury was 2.5 times higher in boys than girls. Traffic injury mortality and pedestrian mortality rates declined significantly in the total group. There was also a significant decline in mortality among cyclists for the total group and female subgroup. Trends in mortality rates among motorcyclists and car occupants showed no significant changes. A long-term decline is more likely to be affected by efforts in the promotion of sustainable and permanent road safety. The reduced risk exposure may also have been influenced by the economic recession.
Panlilio, Leigh V.; Justinova, Zuzana; Trigo, Jose M.; Le Foll, Bernard
Cannabis use has been increasingly accepted legally and in public opinion. However, cannabis has the potential to produce adverse physical and mental health effects and can result in cannabis use disorder (CUD) in a substantial percentage of both occasional and daily cannabis users. Many people have difficulty discontinuing use. Therefore, it would be beneficial to develop safe and effective medications for treating CUD. To achieve this, methods have been developed for screening and evaluating potential medications using animal models and controlled experimental protocols in human volunteers. In this chapter we describe: 1) animal models available for assessing the effect of potential medications on specific aspects of CUD; 2) the main findings obtained so far with these animal models; 3) the approaches used to assess potential medications in humans in laboratory experiments and clinical trials; and 4) the effectiveness of several potential pharmacotherapies on the particular aspects of CUD modeled in these human studies. PMID:27055612
Vandrey, Ryan; Smith, Michael T.; McCann, Una D.; Budney, Alan J.; Curran, Erin M.
Background Sleep difficulty is a common symptom of cannabis withdrawal, but little research has objectively measured sleep or explored the effects of hypnotic medication on sleep during cannabis withdrawal. Methods Twenty daily cannabis users completed a within-subject crossover study. Participants alternated between periods of ad-libitum cannabis use and short-term cannabis abstinence (3 days). Placebo was administered at bedtime during one abstinence period (withdrawal test) and extended-release zolpidem, a non-benzodiazepine GABAA receptor agonist, was administered during the other. Polysomnographic (PSG) sleep architecture measures, subjective ratings, and cognitive performance effects were assessed each day. Results During the placebo-abstinence period, participants had decreased sleep efficiency, total sleep time, percent time spent in Stage 1 and Stage 2 sleep, REM latency and subjective sleep quality, as well as increased sleep latency and time spent in REM sleep compared with when they were using cannabis. Zolpidem attenuated the effects of abstinence on sleep architecture and normalized sleep efficiency scores, but had no effect on sleep latency. Zolpidem was not associated with any significant side effects or next-day cognitive performance impairments. Conclusions These data extend prior research that indicates abrupt abstinence from cannabis can lead to clinically significant sleep disruption in daily users. The findings also indicate that sleep disruption associated with cannabis withdrawal can be attenuated by zolpidem, suggesting that hypnotic medications might be useful adjunct pharmacotherapies in the treatment of cannabis use disorders. PMID:21296508
Donoghue, Kim; Doody, Gillian A; Murray, Robin M; Jones, Peter B; Morgan, Craig; Dazzan, Paola; Hart, Jozella; Mazzoncini, Rodolfo; Maccabe, James H
An earlier age of onset of schizophrenia has been identified as a poor prognostic indicator. The current study examines the interaction effect of gender and cannabis use on age of onset of schizophrenia and schizoaffective disorder. This research forms part of a two-centre epidemiological study of first-episode psychosis and included individuals with a diagnosis of schizophrenia or schizoaffective disorder and an age of onset between age 16 and 45. Kaplan-Meier curves and Cox proportional hazards regression were used to compare the effects of cannabis use and gender on age of first symptom of schizophrenia. Akaike's information criteria were used to find the model with the best fit to the data. Cannabis users had an earlier age of first symptom than non-users. There was an interaction with gender; the gender difference in age of onset was diminished in cannabis smokers compared with non-cannabis smokers. The model including cannabis use interacting with gender was the most parsimonious model, followed by cannabis use alone. The addition of other illegal drug use did not improve the model. Cannabis use is associated with an earlier age of onset of schizophrenia, and the gender difference in age of onset is reduced among cannabis smokers.
Steinmetz, Adam B.; Edwards, Chad R.; Vollmer, Jennifer M.; Erickson, Molly A.; O’Donnell, Brian F.; Hetrick, William P.
Rationale Previous work in humans has shown that chronic cannabis users exhibit disruptions in classical eyeblink conditioning (EBC), a form of associative learning that is known to be dependent on the cerebellum. Based upon previous work in animals, it was hypothesized that these learning deficits were related to cannabinoid receptor (CB1R) downregulation. However, it remains unclear whether there is a recovery of cerebellum-dependent learning after the cessation of cannabis use. Methods Therefore, former cannabis users (n=10), current cannabis users (n=10), and cannabis-naïve controls (n=10), all free of DSM-IV Axis-I or -II disorders, were evaluated. A standard delay EBC procedure was utilized in which paired presentations of a conditioned stimulus (CS; e.g., tone) and a co-terminating unconditioned stimulus (US; e.g., ocular air-puff) were administered, thus eliciting a conditioned eyeblink response (CR). The primary dependent measures were percentage of CRs and CR latency across conditioning blocks. Results Similar to prior studies, current cannabis users exhibited marked impairments in both the acquisition and timing of CRs compared to controls. Although former cannabis users showed intact CR acquisition compared to controls, they exhibited significantly impaired (shorter) CR latencies. In both cannabis groups, UR amplitude did not differ from controls, indicating normal US processing. Conclusions These data suggest that a recovery of function has occurred for the learning of the CS–US association, while the accurate timing of the CR shows lasting impairments. Taken together, these results suggest that heavy cannabis use can disrupt timing-related synaptic plasticity within the cerebellum, even after the cessation of cannabis use. PMID:22134474
Kreuter, M; Nowak, D; Rüther, T; Hoch, E; Thomasius, R; Vogelberg, C; Brockstedt, M; Hellmann, A; Gohlke, H; Jany, B; Loddenkemper, R
In this position paper, the adverse health effects of cannabis are reviewed based on the existing scientific literature; in addition possible symptom-relieving effects on some diseases are depicted. In Germany, cannabis is the most widely used illicit drug. Approximately 600,000 adult persons show abusive or addictive cannabis consumption. In 12 to 17 year old adolescents, cannabis use increased from 2011 to 2014 from 2.8 to 6.4%, and the frequency of regular use from 0.2 to 1.5%. Currently, handling of cannabinoids is much debated in politics as well as in general public. Health aspects have to be incorporated into this debate. Besides analysing mental and neurological side effects, this position paper will mainly focus on the influences on the bronchopulmonary and cardiovascular system. There is strong evidence for the induction of chronic bronchitis. Allergic reactions including asthma are known, too. Associations with other diseases like pulmonary emphysema, lung cancer and pneumonia are not sufficiently proven, however cannot be excluded either. In connection with the use of cannabis cardiovascular events such as coronary syndromes, peripheral vascular diseases and cerebral complications have been noted. Often, the evidence is insufficient due to various reasons; most notably, the overlapping effects of tobacco and cannabis use can frequently not be separated adequately. Empirically, early beginning, high-dosed, long-lasting and regular cannabis consumption increase the risk of various psychological and physical impairments and negatively affect age-based development. Concerns therefore relate especially to children and adolescents. There is only little scientific evidence for medical benefits through cannabis as a remedy; systematic research of good quality, in particular prospective, randomised, placebo-controlled double-blinded studies are rare. The medical societies signing this position paper conclude that cannabis consumption is linked to adverse health
Pavisian, Bennis; MacIntosh, Bradley J.; Szilagyi, Greg; Staines, Richard W.; O'Connor, Paul
Objective: To determine functional and structural neuroimaging correlates of cognitive dysfunction associated with cannabis use in multiple sclerosis (MS). Methods: In a cross-sectional study, 20 subjects with MS who smoked cannabis and 19 noncannabis users with MS, matched on demographic and neurologic variables, underwent fMRI while completing a test of working memory, the N-Back. Resting-state fMRI and structural MRI data (lesion and normal-appearing brain tissue volumes, diffusion tensor imaging metrics) were also collected. Neuropsychological data pertaining to verbal (Selective Reminding Test Revised) and visual (10/36 Spatial Recall Test) memory, information processing speed (Paced Auditory Serial Addition Test [2- and 3-second versions] and Symbol Digit Modalities Test), and attention (Word List Generation) were obtained. Results: The cannabis group performed more poorly on the more demanding of the Paced Auditory Serial Addition Test tasks (i.e., 2-second version) (p < 0.02) and the 10/36 Spatial Recall Test (p < 0.03). Cannabis users had more diffuse cerebral activation across all N-Back trials and made more errors on the 2-Back task (p < 0.006), during which they displayed increased activation relative to nonusers in parietal (p < 0.007) and anterior cingulate (p < 0.001) regions implicated in working memory. No group differences in resting-state networks or structural MRI variables were found. Conclusions: Patients with MS who smoke cannabis are more cognitively impaired than nonusers. Cannabis further compromises cerebral compensatory mechanisms, already faulty in MS. These imaging data boost the construct validity of the neuropsychological findings and act as a cautionary note to cannabis users and prescribers. PMID:24789863
Park, Boram; McPartland, John M; Glass, Michelle
In most countries Cannabis is the most widely used illegal drug. Its use during pregnancy in developed nations is estimated to be approximately 10%. Recent evidence suggests that the endogenous cannabinoid system, now consisting of two receptors and multiple endocannabinoid ligands, may also play an important role in the maintenance and regulation of early pregnancy and fertility. The purpose of this review is therefore twofold, to examine the impact that cannabis use may have on fertility and reproduction, and to review the potential role of the endocannabinoid system in hormonal regulation, embryo implantation and maintenance of pregnancy.
King, G.R.; Ernst, T.; Deng, W.; Stenger, A.; Gonzales, R.M.K; Nakama, H.; Chang, L.
Cannabis is the most abused illegal substance in the United States. Alterations in brain function and motor behavior have been reported in chronic cannabis users, but the results have been variable. The current study aimed to determine whether chronic active cannabis use in humans may alter psychomotor function, brain activation, and hypothalamic-pituitary-axis (HPA) function in men and women. 30 cannabis users (16 men and 14 women, 18 to 45 years old) and 30 non-drug user controls (16 men and 14 women, 19 to 44 years old) were evaluated with neuropsychological tests designed to assess motor behavior and functional MRI (fMRI), using a 3 Tesla scanner, during a visually paced finger-sequencing task, cued by a flashing checkerboard (at 2 or 4 Hz). Salivary cortisol was measured to assess HPA function. Male, but not female, cannabis users had significantly slower performance on psychomotor speed tests. As a group, cannabis users had greater activation in BA 6 than controls, while controls had greater activation in the visual area BA 17 than cannabis users. Cannabis users also had higher salivary cortisol levels than controls (p = 0.002). Chronic active cannabis use is associated with slower and less efficient psychomotor function, especially in the male users, as indicated by a shift from regions involved with automated visually guided responses to more executive or attentional control areas. These brain activities may be attenuated by the higher cortisol levels in the cannabis users which in turn may lead to less efficient visual-motor function. PMID:22159107
Schmits, Emilie; Mathys, Cécile; Quertemont, Etienne
This study identified protective and risk factors of cannabis use initiation, including expectancies and social anxiety. A questionnaire was completed twice by 877 teenagers. Logistic regressions, mediation and moderation analyses were performed. Significant risk factors were alcohol use, peer users, perceptual enhancement, and craving expectancies. Protective factors were negative behavior expectancies and social anxiety. Social anxiety protected from initiation through the mediating role of perceptual enhancement and craving expectancies, whatever the role of peer users and alcohol use. Findings are discussed in terms of risk and protection, in an overall approach including internalizing factors. Results support the identification of an internalizing profile of adolescents for prevention or treatment and the importance of social anxiety and expectancies in intervention.
Cousijn, Janna; Wiers, Reinout W; Ridderinkhof, K Richard; van den Brink, Wim; Veltman, Dick J; Porrino, Linda J; Goudriaan, Anna E
Decision-making deficits are thought to play an important role in the development and persistence of substance use disorders. Individual differences in decision-making abilities and their underlying neurocircuitry may, therefore, constitute an important predictor for the course of substance use and the development of substance use disorders. Here, we investigate the predictive value of decision making and neural mechanisms underlying decision making for future cannabis use and problem severity in a sample of heavy cannabis users. Brain activity during a monetary decision-making task (Iowa gambling task) was compared between 32 heavy cannabis users and 41 matched non-using controls using functional magnetic resonance imaging. In addition, within the group of heavy cannabis users, associations were examined between task-related brain activations, cannabis use and cannabis use-related problems at baseline, and change in cannabis use and problem severity after a 6-month follow-up. Despite normal task performance, heavy cannabis users compared with controls showed higher activation during wins in core areas associated with decision making. Moreover, within the group of heavy cannabis users, win-related activity and activity anticipating loss outcomes in areas generally involved in executive functions predicted change in cannabis use after 6 months. These findings are consistent with previous studies and point to abnormal processing of motivational information in heavy cannabis users. A new finding is that individuals who are biased toward immediate rewards have a higher probability of increasing drug use, highlighting the importance of the relative balance between motivational processes and regulatory executive processes in the development of substance use disorders.
de Assis, Simone Gonçalves; Gomes, Romeu; Pires, Thiago de Oliveira
OBJECTIVE To analyze the relationships between sexual behavior and risk factors to physical and mental health in adolescents. METHODS Study of 3,195 pupils aged 15 to 19 in secondary education, in public and private schools in 10 state capitals in Brazil between 2007 and 2008. Multi-stage (schools and pupils) cluster sampling was used in each city and public and private educational network. All of the students selected completed a questionnaire on the following items: socioeconomic and demographic data; sexual behavior; having sex with those of the same sex, the opposite sex, or both; alcohol and cannabis use; using condoms; traumatic sexual experiences as a child or adolescent; suicidal thoughts. The analysis included describing frequencies, Chi-square test, analysis of multiple and cluster correspondence. Responses to an open ended question in which the adolescent expressed general comments about themselves and their lives were qualitatively analyzed using content analysis. RESULTS Around 3.0% of adolescents reported homosexual or bisexual behavior, with no difference according to sex, age, skin color, social status family structure or educational network. Adolescents with homosexual/bisexual sexual behavior, compared to their heterosexual peers, reported: (p < 0.05): getting drunk (18.7% and 10.5%, respectively), frequent cannabis use (6.1% and 2.1%, respectively), suicidal thoughts (42.5% and 18.7%, respectively), and having been the victim of sexual violence (11.7% and 1.5%; respectively). Adolescents with homosexual/bisexual sexual behavior reported that they used condoms less frequently (74.2%) than their heterosexual peers (48.6%, p < 0.001). In the correspondence analysis, three groups were found, one composed of adolescents with homosexual/bisexual behavior and experiencing risk factors; suffering sexual violence, never using a condom, suicidal thoughts, frequent cannabis use; another composed of occasional cannabis and condom users, who got drunk
Becker, Sara J; Midoun, Miriam M; Zeithaml, Valarie A; Clark, Melissa A; Spirito, Anthony
Professional psychologists are increasingly encouraged to document and evaluate the quality of the treatment they provide. However, there is a significant gap in knowledge about the extent to which extant definitions of treatment quality converge with patient perceptions. The primary goal of this study was to examine how adolescent substance users (ASU) and their caregivers perceive treatment quality. The secondary goal was to determine how these perceptions align with expert-derived definitions of ASU treatment quality and dimensions of perceived quality used frequently in other service disciplines. Focus groups and individual interviews were conducted with 24 ASU and 29 caregivers to explore how participants conceptualize a quality treatment experience. Content analysis identified three major dimensions of perceived treatment quality, each of which contained three sub-dimensions: Therapeutic Relationship (i.e., Acceptance, Caring, Connection), Provider Characteristics (i.e., Experience, Communication Skills, Accessibility), and Treatment Approach (i.e., Integrated Care, Use of Structure, and Parent Involvement). Results revealed modest convergence between patient perceptions and existing definitions of quality, with several meaningful discrepancies. Most notably, the Therapeutic Relationship was the most important dimension to ASU and their caregivers, while expert-derived definitions emphasized the Treatment Approach. Implications for practicing psychologists to enhance training and supervision, quality improvement, and health education initiatives are discussed.
Becker, Sara J.; Midoun, Miriam M.; Zeithaml, Valarie A.; Clark, Melissa A.; Spirito, Anthony
Professional psychologists are increasingly encouraged to document and evaluate the quality of the treatment they provide. However, there is a significant gap in knowledge about the extent to which extant definitions of treatment quality converge with patient perceptions. The primary goal of this study was to examine how adolescent substance users (ASU) and their caregivers perceive treatment quality. The secondary goal was to determine how these perceptions align with expert-derived definitions of ASU treatment quality and dimensions of perceived quality used frequently in other service disciplines. Focus groups and individual interviews were conducted with 24 ASU and 29 caregivers to explore how participants conceptualize a quality treatment experience. Content analysis identified three major dimensions of perceived treatment quality, each of which contained three sub-dimensions: Therapeutic Relationship (i.e., Acceptance, Caring, Connection), Provider Characteristics (i.e., Experience, Communication Skills, Accessibility), and Treatment Approach (i.e., Integrated Care, Use of Structure, and Parent Involvement). Results revealed modest convergence between patient perceptions and existing definitions of quality, with several meaningful discrepancies. Most notably, the Therapeutic Relationship was the most important dimension to ASU and their caregivers, while expert-derived definitions emphasized the Treatment Approach. Implications for practicing psychologists to enhance training and supervision, quality improvement, and health education initiatives are discussed. PMID:27524856
Bonnet, Udo; Specka, Michael; Scherbaum, Norbert
The non-medical (recreational) use of cannabis is common particularly among young adults. In light of the ongoing legalization debate the clinical impact of physical and psychosocial consequences of regular recreational cannabis consumption should be presented. Health consequences appear to be more pronounced the earlier the regular recreational cannabis use had been started in the individual's development. There is an increasing demand from recreational cannabis users for medical treatment of cannabis-related complaints including the cannabis withdrawal syndrome. Physical sequelae such as chronic bronchitis, cyclical hyperemesis and fertility problems are usually reversible along with abstinence. The often debilitating cannabis-related mental and cognitive complaints respond on a qualified inpatient detoxification treatment with high effect sizes (Cohen's d 0.7 -1.4). The severity of the cannabis addiction benefits sustainably from psychotherapeutic approaches and individual psychosocial counseling (Cohen's d 0,5-1,2). Currently, the actual health hazard of recreational cannabis use was evaluated by addiction experts to be significantly lower than that of tobacco or alcohol use.
Minor, Kyle S; Firmin, Ruth L; Bonfils, Kelsey A; Chun, Charlotte A; Buckner, Julia D; Cohen, Alex S
Evidence suggests that divergent thinking (DT), a measure of creativity, is associated with positive schizotypy and cannabis use. Given the high rates of cannabis use among those with schizotypy, it is unclear if the relation of DT to schizotypy is due to co-occurring cannabis use. In this study, we examined the relations between DT, schizotypy, and cannabis use among positive schizotypy (n=66), negative schizotypy (n=22), and non-schizotypy (n=60) groups. Results revealed that DT was greater in the positive schizotypy group, on the order of small to medium effects, compared to negative and non-schizotypy groups. Cannabis use and DT were associated in the non-schizotypy group, but not in the positive or negative schizotypy groups. Across all groups, positive schizotypy significantly predicted DT; however, cannabis use was not a significant predictor of DT. In line with previous findings, cannabis use and DT were only related in individuals low in creativity. This suggests that a ceiling effect may be present, with only cannabis users who are low in creativity receiving any increase in DT. Future research should aim to clarify the DT-cannabis relationship.
Aspis, Itay; Feingold, Daniel; Weiser, Mark; Rehm, Jurgen; Shoval, Gal; Lev-Ran, Shaul
Cannabis is the most widely used illicit substance among individuals with depressive disorders. This study aimed to evaluate whether among individuals with depressive disorders, higher frequency of cannabis use would be associated with poorer Quality of Life (QoL), based on a large nationally representative US sample. Individuals with depressive disorders (N=3416) were divided into categories according to no use (N=3096), occasional use (less than weekly, N=176) and regular (at least weekly, N=144) use of cannabis in the past 12 months. QoL was assessed using the Short-Form 12 (SF-12) questionnaire. Women who used cannabis regularly had a significantly lower SF-12 Mental Component Summary score (MCS) compared to non-users, with a mean difference of 0.4 Standard Deviations (SDs). Comparison of subscale scores showed no significant differences. No significant difference was noted when comparing women who used cannabis occasionally to non-users. No differences were found among men when comparing MCS and mental subscale scores of both regular and occasional users to non-users. Our findings highlight the importance of taking gender and the frequency of cannabis use into account, when assessing functional and emotional aspects of cannabis use among individuals with depressive disorders.
Nuno-Gutierrez, Bertha Lidia; Alvarez-Nemegyei, Jose; Rodriguez-Cerda, Oscar
The aim of this study was to explore the social representations used by the parents of adolescent drug users to explain the onset of drug use. Differences in explanations between the parents of male and female adolescents were also explored. Sixty parents who accompanied their children to four rehabilitation centers in 2004 completed two…
Walburg, Vera; Moncla, Dany; Mialhes, Aurélie
Background: Cannabis is a substance frequently consumed by adolescents, which is a risk factor for many psychopathological disorders. At the same time, adolescents in high-schools are likely to be exposed to significant stress from school that can sometimes lead to a burnout syndrome. Objective: The purpose of this study is to explore the impact…
Korhonen, Tellervo; van Leeuwen, Andrea Prince; Reijneveld, Sijmen A.; Ormel, Johan; Verhulst, Frank C.; Huizink, Anja C.
Objective: To examine externalizing behavior problems and cigarette smoking as predictors of subsequent cannabis use. Method: Dutch adolescents (N = 1,606; 854 girls and 752 boys) from the TRacking Adolescents' Individual Lives Survey (TRAILS) ongoing longitudinal study were examined at baseline (ages 10-12 [T1]) and at two follow-up assessments…
Kim, Sung-Wan; Dodd, Seetal; Berk, Lesley; Kulkarni, Jayashri; de Castella, Anthony; Fitzgerald, Paul B.; Kim, Jae-Min; Yoon, Jin-Sang
Objective To investigate the impact of regular cannabis use on long-term remission of mood symptoms in bipolar spectrum disorders. Methods The 24-month prospective observational study included patients (n=239) with bipolar I disorder and schizoaffective disorder, bipolar type. Participants were classified as regular cannabis users (three times or more per week) or non-users. The primary outcome measure was the achievement of remission on the evaluations during the 24 months. Results Of the 234 participants for whom data was available, 25 (10.7%) were regular cannabis users, and the group comprised significantly more males than females. In the total population, cannabis use was significantly associated with decreased likelihood of remission during the 24-month follow-up period. Subgroup analyses showed that cannabis use was significantly associated with lower remission rates on the Hamilton Depression Rating Scale in females (n=139) and patients prescribed mood stabilizers alone (n=151), whereas in males (n=95) and patients prescribed olanzapine and/or a mood stabilizer (n=83), cannabis use was significantly associated with lower remission rates on the Young Mania Rating Scale. Remission rates were lowest in the concurrent cannabis and tobacco smoking group (n=22) followed by the tobacco smoking only group (n=97), and the non-smoker group (n=116). The post-hoc analysis revealed that all remission rates were significantly lower in the concurrent cannabis and the tobacco smoking group compared to the non-smoker group. Conclusion Cannabis use negatively affects the long-term clinical outcome in patients with bipolar spectrum disorders. A comprehensive assessment and integrated management of cannabis use are required to achieve better treatment outcomes for bipolar spectrum disorders. PMID:26207128
Hoffenberg, Edward J; Newman, Heike; Collins, Colm; Tarbell, Sally; Leinwand, Kristina
The trend toward decriminalization of cannabis (marijuana) continues sweeping across the United States. Colorado has been a leader of legalization of medical and recreational cannabis use. The growing public interest in the medicinal properties of cannabis and its use by patients with a variety of illnesses including inflammatory bowel disease (IBD) makes it important for pediatric gastroenterologists to understand this movement and its potential effect on patients. This article describes the path to legalization and "medicalization" of cannabis in Colorado and the public perception of safety despite the known adverse health effects of use. We delineate the mammalian endocannabinoid system and our experience of caring for children and adolescents with IBD in an environment of increasing awareness and acceptance of its use. We then summarize the rationale for considering that cannabis may have beneficial and harmful effects for patients with IBD. Finally, we highlight the challenges federal laws impose on conducting research on cannabis in IBD. The intent of this article is to inform health care providers about the issues around cannabis use and research in adolescents and young adults with IBD.
Murray, Robin M.; Quigley, Harriet; Quattrone, Diego; Englund, Amir; Di Forti, Marta
Epidemiological evidence demonstrates that cannabis use is associated with an increased risk of psychotic outcomes, and confirms a dose‐response relationship between the level of use and the risk of later psychosis. High‐potency cannabis and synthetic cannabinoids carry the greatest risk. Experimental administration of tetrahydrocannabinol, the active ingredient of cannabis, induces transient psychosis in normal subjects, but this effect can be ameliorated by co‐administration of cannabidiol. This latter is a constituent of traditional hashish, but is largely absent from modern high‐potency forms of cannabis. Argument continues over the extent to which genetic predisposition is correlated to, or interacts with, cannabis use, and what proportion of psychosis could be prevented by minimizing heavy use. As yet, there is not convincing evidence that cannabis use increases risk of other psychiatric disorders, but there are no such doubts concerning its detrimental effect on cognitive function. All of the negative aspects are magnified if use starts in early adolescence. Irrespective of whether use of cannabis is decriminalized or legalized, the evidence that it is a component cause of psychosis is now sufficient for public health messages outlining the risk, especially of regular use of high‐potency cannabis and synthetic cannabinoids. PMID:27717258
Chabrol, Henri; Beck, Charline; Laconi, Stéphanie
The Marijuana Motives Measure (MMM), which is derived from a scale measuring alcohol use motives, has been the main instrument used to explore the role of motives in cannabis use and related problems. Two studies attempted to developed specific cannabis use motives but none of them showed a unique association to cannabis use and problems when controlling for MMM motives. The aim of our study was to examine if additional motives contributed to problematic use beyond MMM motives and psychopathological symptoms. Participants were 249 high-school students who completed the Cannabis Use Disorder Identification Test-Revised (CUDIT-R) assessing cannabis use and problematic use, the MMM and a new scale measuring motives derived from clinical experience with adolescents using cannabis (CED motives), and scales measuring anxiety and depressive symptoms and borderline personality traits. Among the 107 participants using cannabis, 39 reached the cut-off score for problematic cannabis use. Hierarchical multiple regression analyses controlling for psychopathological variables showed that only one CED motives, Health (sleep, form, energy, appetite, health), was a significant predictor of both frequency of use and problematic use symptoms. The importance of Health motive may be linked to the role of depressive symptoms and may have implication for treatment. We suggest to add the Health subscale to the MMM and to further study the role of health motive in both use and dependence.
Murray, Robin M; Quigley, Harriet; Quattrone, Diego; Englund, Amir; Di Forti, Marta
Epidemiological evidence demonstrates that cannabis use is associated with an increased risk of psychotic outcomes, and confirms a dose-response relationship between the level of use and the risk of later psychosis. High-potency cannabis and synthetic cannabinoids carry the greatest risk. Experimental administration of tetrahydrocannabinol, the active ingredient of cannabis, induces transient psychosis in normal subjects, but this effect can be ameliorated by co-administration of cannabidiol. This latter is a constituent of traditional hashish, but is largely absent from modern high-potency forms of cannabis. Argument continues over the extent to which genetic predisposition is correlated to, or interacts with, cannabis use, and what proportion of psychosis could be prevented by minimizing heavy use. As yet, there is not convincing evidence that cannabis use increases risk of other psychiatric disorders, but there are no such doubts concerning its detrimental effect on cognitive function. All of the negative aspects are magnified if use starts in early adolescence. Irrespective of whether use of cannabis is decriminalized or legalized, the evidence that it is a component cause of psychosis is now sufficient for public health messages outlining the risk, especially of regular use of high-potency cannabis and synthetic cannabinoids.
Palali, Ali; van Ours, Jan C
In the Netherlands, cannabis use is quasi-legalized. Small quantities of cannabis can be bought in cannabis shops. We investigate how the distance to the nearest cannabis shop affects the age of onset of cannabis use. We use a mixed proportional hazard rate framework to take account of observable as well as unobservable characteristics that influence the uptake of cannabis. We find that distance matters. Individuals who grow up within 20 km of a cannabis shop have a lower age of onset.
Hartman, Rebecca L.; Huestis, Marilyn A.
BACKGROUND Cannabis is the most prevalent illicit drug identified in impaired drivers. The effects of cannabis on driving continue to be debated, making prosecution and legislation difficult. Historically, delays in sample collection, evaluating the inactive Δ9-tetrahydrocannabinol (THC) metabolite 11-nor-9-carboxy-THC, and polydrug use have complicated epidemiologic evaluations of driver impairment after cannabis use. CONTENT We review and evaluate the current literature on cannabis’ effects on driving, highlighting the epidemiologic and experimental data. Epidemiologic data show that the risk of involvement in a motor vehicle accident (MVA) increases approximately 2-fold after cannabis smoking. The adjusted risk of driver culpability also increases substantially, particularly with increased blood THC concentrations. Studies that have used urine as the biological matrix have not shown an association between cannabis and crash risk. Experimental data show that drivers attempt to compensate by driving more slowly after smoking cannabis, but control deteriorates with increasing task complexity. Cannabis smoking increases lane weaving and impaired cognitive function. Critical-tracking tests, reaction times, divided-attention tasks, and lane-position variability all show cannabis-induced impairment. Despite purported tolerance in frequent smokers, complex tasks still show impairment. Combining cannabis with alcohol enhances impairment, especially lane weaving. SUMMARY Differences in study designs frequently account for inconsistencies in results between studies. Participant-selection bias and confounding factors attenuate ostensible cannabis effects, but the association with MVA often retains significance. Evidence suggests recent smoking and/or blood THC concentrations 2–5 ng/mL are associated with substantial driving impairment, particularly in occasional smokers. Future cannabis-and-driving research should emphasize challenging tasks, such as divided attention
Rathbone, John; Variend, Hannele; Mehta, Hetal
Background Many people with schizophrenia use cannabis and its effects on the illness are unclear. Objectives To evaluate the effects of cannabis use on people with schizophrenia and schizophrenia-like illnesses. Search methods We searched the Cochrane Schizophrenia Group Trials Register (April 2007) which is based on regular searches of BIOSIS, CENTRAL, CINAHL, EMBASE, MEDLINE and PsycINFO. Selection criteria We included all randomised trials involving cannabinoids and people with schizophrenia or schizophrenia-like illnesses. Data collection and analysis We extracted data independently. For dichotomous data we calculated relative risks (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis, based on a fixed effects model. We calculated the numbers needed to treat/harm (NNT/NNH). For continuous data, we calculated weighted mean differences (WMD) again based on a fixed effects model. Main results We identified one randomised trial. No significant differences were found between the Cannabis and Psychosis Therapy (CAP) intervention group and the Psychoeducaton (PE) intervention for use of cannabis at three months assessment (n=47, RR 1.04 CI 0.6 to 1.7). BPRS-extended scale scores at three months assessment (n=47, WMD −3.60 CI −12.8 to 5.6) and nine months assessment (n=47, WMD 0.80 CI −7.5 to 9.1) were non-significant between CAP and PE. We found no significant improvement in social functioning in the CAP group compared with PE (at 3 months, n=47, WMD −0.80 CI −10 to 8.4) and (at 9 months, n=47, WMD −4.70 CI −14.5 to 5.1). Authors’ conclusions At present, there is insufficient evidence to support or refute the use of cannabis/cannabinoid compounds for people suffering with schizophrenia. This review highlights the need for well designed, conducted and reported clinical trials to address the potential effects of cannabis based compounds for people with schizophrenia. PMID:18646115
Hazekamp, A; Fischedick, J T
The medicinal use of Cannabis is increasing as countries worldwide are setting up official programs to provide patients with access to safe sources of medicinal-grade Cannabis. An important question that remains to be answered is which of the many varieties of Cannabis should be made available for medicinal use. Drug varieties of Cannabis are commonly distinguished through the use of popular names, with a major distinction being made between Indica and Sativa types. Although more than 700 different cultivars have already been described, it is unclear whether such classification reflects any relevant differences in chemical composition. Some attempts have been made to classify Cannabis varieties based on chemical composition, but they have mainly been useful for forensic applications, distinguishing drug varieties, with high THC content, from the non-drug hemp varieties. The biologically active terpenoids have not been included in these approaches. For a clearer understanding of the medicinal properties of the Cannabis plant, a better classification system, based on a range of potentially active constituents, is needed. The cannabinoids and terpenoids, present in high concentrations in Cannabis flowers, are the main candidates. In this study, we compared cultivars obtained from multiple sources. Based on the analysis of 28 major compounds present in these samples, followed by principal component analysis (PCA) of the quantitative data, we were able to identify the Cannabis constituents that defined the samples into distinct chemovar groups. The study indicates the usefulness of a PCA approach for chemotaxonomic classification of Cannabis varieties.
Robinson, Elizabeth J.; Davidson, Lisa S.; Uchanski, Rosalie M.; Brenner, Christine M.; Geers, Ann E.
Background For pediatric cochlear implant (CI) users, CI processor technology, map characteristics and fitting strategies are known to have a substantial impact on speech perception scores at young ages. It is unknown whether these benefits continue over time as these children reach adolescence. Purpose To document changes in CI technology, map characteristics, and speech perception scores in children between elementary grades and high school, and to describe relations between map characteristics and speech perception scores over time. Research Design A longitudinal design with participants 8–9 years old at session 1 and 15–18 years old at session 2. Study Sample Participants were 82 adolescents with unilateral CIs, who are a subset of a larger longitudinal study. Mean age at implantation was 3.4 years (range: 1.7 – 5.4), and mean duration of device use was 5.5 years (range: 3.8–7.5) at session 1 and 13.3 years (range: 10.9–15) at session 2. Data Collection and Analysis Speech perception tests at sessions 1 and 2 were the Lexical Neighborhood word Test (LNT-70) and Bamford-Kowal-Bench sentences in quiet (BKB-Q), presented at 70 dB SPL. At session 2, the LNT was also administered at 50 dB SPL (LNT-50) and BKB sentences were administered in noise with a +10 dB SNR (BKB-N). CI processor technology type and CI map characteristics (coding strategy, number of electrodes, map threshold levels [T levels], and map comfort levels [C levels]) were obtained at both sessions. Electrical dynamic range [EDR] was computed [C level – T level], and descriptive statistics, correlations, and repeated-measures ANOVAs were employed. Results Participants achieved significantly higher LNT and BKB scores, at 70 dB SPL, at ages 15-18 than at ages 8-9 years. Forty-two participants had 1-3 electrodes either activated or deactivated in their map between test sessions, and 40 had no change in number of active electrodes (mean change: -0.5; range: -3 to +2). After conversion from
Gassman, Ruth; Nowicke, Carole E.; Jun, Mi Kung
Survey responses by nonexperimental drug users in grades 6-12 were examined to determine whether MA users and nonusers with shared individual characteristics experience differential rates of police trouble, and whether specific factors place some users at greater risk than others. Findings showed that police trouble is pronounced for MA users,…
Hughes, John R.; Naud, Shelly; Budney, Alan J.; Fingar, James R.; Callas, Peter W.
We attempted to replicate and add to our prior study of attempts to stop or reduce cannabis use among daily cannabis users trying to change on their own, by observing a larger sample and adding further clinically-relevant outcomes. Daily users (n = 193) who intended to stop or reduce sometime in the next 3 months called an Interactive Voice Response system each morning for 3 months to report on cannabis use, attempts to stop or reduce, withdrawal symptoms, etc., on the prior day. This study replicated our prior findings that a) cannabis users trying to change make many, and often rapid, transitions among use as usual, reduction and abstinence; b) reduction attempts are more common than abstinence attempts; c) quit and reduction attempts are short-lived and few participants achieve long-term abstinence; d) alcohol and drug use are not greater on abstinence days; and e) few users seek treatment. Novel findings included f) a greater number of days of abstinence or intentional reduction predicted a greater decline in cannabis dependence; g) most users do not prepare before their quit attempt; h) coping outcomes during abstinence predict increased duration of abstinence; i) tobacco use is less common on days of abstinence; and j) withdrawal symptoms occur even with short quit attempts. Replication tests in more generalizable samples and of longer duration are indicated. Further natural history studies are likely to provide information to help improve the content of psychological treatments for cannabis use. PMID:26828641
Hughes, John R; Naud, Shelly; Budney, Alan J; Fingar, James R; Callas, Peter W
We attempted to replicate and add to our prior study of attempts to stop or reduce cannabis use among daily cannabis users trying to change on their own, by observing a larger sample and adding further clinically relevant outcomes. Daily users (n = 193) who intended to stop or reduce sometime in the next 3 months called an Interactive Voice Response system each morning for 3 months to report on cannabis use, attempts to stop or reduce, withdrawal symptoms, and so forth, on the prior day. This study replicated our prior findings that (a) cannabis users trying to change make many, and often rapid, transitions among use as usual, reduction, and abstinence; (b) reduction attempts are more common than abstinence attempts; (c) quit and reduction attempts are short-lived and few participants achieve long-term abstinence; (d) alcohol and drug use are not greater on abstinence days; and (e) few users seek treatment. Novel findings included (f) a greater number of days of abstinence or intentional reduction predicted a greater decline in cannabis dependence, (g) most users do not prepare before their quit attempt, (h) coping outcomes during abstinence predict increased duration of abstinence, (i) tobacco use is less common on days of abstinence, and (j) withdrawal symptoms occur even with short quit attempts. Replication tests in more generalizable samples and of longer duration are indicated. Further natural history studies are likely to provide information to help improve the content of psychological treatments for cannabis use. (PsycINFO Database Record
Álvarez, Arturo; Gamella, Juan F; Parra, Iván
First, this paper estimates the dimensions of the market for cannabis in Spain using data on the extent of consumption and the main patterns of use of consumers. Then the paper reviews the hypothetical production and distribution costs of these drugs in different production regimes under different legal conditions. The review shows that current prices of cannabis in the illegal market could be notably reduced if production and distribution of cannabis were decriminalized and even more if they were performed by legal enterprises. Thirdly, we examine the relationship between prices and consumption levels by analysing the price elasticity of demand. A fall in the prices of cannabis products will likely result in an increase in the number of users and in the total amount consumed. Lastly we consider several alternatives for the taxation of cannabis derivatives to counteract the likely fall in prices, and their pros and cons.
Khiabani, Hassan Z; Christophersen, Asbjørg S; Mørland, Jørg
Delta (9)-tetrahydrocannabinol (THC), the most important psychoactive substance in cannabis, is frequently detected in blood from apprehended drivers suspected for drugged driving. Both experimental and epidemiological studies have demonstrated the negative effects of THC upon cognitive functions and psychomotor skills. These effects could last longer than a measurable concentration of THC in blood. Culpability studies have recently demonstrated an increased risk of becoming responsible in fatal or injurious traffic accidents, even with low blood concentrations of THC. It has also been demonstrated that there is a correlation between the degree of impairment, the drug dose and the THC blood concentration. It is very important to focus on the negative effect of cannabis on fitness to drive in order to prevent injuries and loss of human life and to avoid large economic consequences to the society.
Short overviews are presented on the historical uses of cannabis in the Middle East and on the more recent scientific and medical research on phytocannabinoids and the endocannabinoid system, with emphasis on research contributions from Israel. These are followed by examples of research projects and clinical trials with cannabinoids and by a short report on the regulation of medical marijuana in Israel, which at present is administered to over 22,000 patients.
Skopp, Gisela; Richter, Barbara; Pötsch, Lucia
Low concentrations of THC and 11-hydroxy-THC in serum samples are often claimed not to result from recent cannabis use. Prediction of time of exposure is difficult, especially if distinctive features of drug use could not be observed. Therefore, the aim of the study was to investigate the presence of THC and 11-hydroxy-THC in serum samples as well as to obtain preliminary data on the analyte profile for a time window of 24-48 hours after discontinuation of cannabis smoking. Serum samples from heavy (n = 12, > 1 joint/day), moderate (n = 11, < or = 1 joint/day) and light (n = 6, < 1 joint/week) smokers of cannabis were analyzed for THC, 11-hydroxy-THC and free THC-COOH by GC/MS as well as for glucuronidated THC-COOH by LC/MS-MS. The blood samples were collected 24-48 hours after abstaining from cannabis use. Additionally, 8 specimens were obtained from persons after discontinuation of the drug for more than 48 hours. During collection of the blood samples, distinctive effects due to drug use could not be observed. For heavy users of cannabis, THC was detectable in 8 samples, and in 5 cases both biologically active compounds, THC and 11-hydroxy-THC, were present (1.3-6.4 ng THC/mL serum, 0.5-2.4 ng 11-hydroxy-THC/mL serum). Among moderate users, in 1 sample 1.8 ng THC/mL serum and 1.3 ng 11-hydroxy-THC/mL serum were determined, and another sample was tested positive with low concentrations close to the limit of detection. In serum samples of light users both analytes could not be detected, indicating that in those persons a positive finding of THC and 11-hydroxy-THC may rather result from recent consumption than from cannabis use 1 or 2 days prior to blood sampling. The concentrations of THC-COOH and its glucuronide covered a wide range in all groups of cannabis users. However, there was a trend to higher concentrations in heavy users compared to moderate users, and the mean concentration was smaller in light smokers than in moderate smokers. Overall, the findings
Marshall, Kushani; Gowing, Linda; Ali, Robert; Le Foll, Bernard
Background Cannabis is the most prevalent illicit drug in the world. Demand for treatment of cannabis use disorders is increasing. There are currently no pharmacotherapies approved for treatment of cannabis use disorders. Objectives To assess the effectiveness and safety of pharmacotherapies as compared with each other, placebo or supportive care for reducing symptoms of cannabis withdrawal and promoting cessation or reduction of cannabis use. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (to 4 March 2014), MEDLINE (to week 3 February 2014), EMBASE (to 3 March 2014) and PsycINFO (to week 4 February 2014). We also searched reference lists of articles, electronic sources of ongoing trials and conference proceedings, and contacted selected researchers active in the area. Selection criteria Randomised and quasi-randomised controlled trials involving the use of medications to reduce the symptoms and signs of cannabis withdrawal or to promote cessation or reduction of cannabis use, or both, in comparison with other medications, placebo or no medication (supportive care) in participants diagnosed as cannabis dependent or who were likely to be dependent. Data collection and analysis We used standard methodological procedures expected by The Cochrane Collaboration. Two review authors assessed studies for inclusion and extracted data. All review authors confirmed the inclusion decisions and the overall process. Main results We included 14 randomised controlled trials involving 958 participants. For 10 studies the average age was 33 years; two studies targeted young people; and age data were not available for two studies. Approximately 80% of study participants were male. The studies were at low risk of selection, performance, detection and selective outcome reporting bias. Three studies were at risk of attrition bias. All studies involved comparison of active medication and placebo. The medications included preparations containing
Brunt, Tibor M; van Genugten, Marianne; Höner-Snoeken, Kathrin; van de Velde, Marco J; Niesink, Raymond J M
In The Netherlands, pharmaceutical-grade cultivated cannabis is distributed for medicinal purposes as commissioned by the Ministry of Health. Few studies have thus far described its therapeutic efficacy or subjective (adverse) effects in patients. The aims of this study are to assess the therapeutic satisfaction within a group of patients using prescribed pharmaceutical-grade cannabis and to compare the subjective effects among the available strains with special focus on their delta-9-tetrahydrocannabinol and cannabidiol content. In a cross-sectional and natural design, users of pharmaceutical-grade cannabis were investigated with questionnaires. Medical background of the patients was asked as well as experienced therapeutic effects and characteristics of cannabis use. Subjective effects were measured with psychometric scales and used to compare among the strains of cannabis used across this group of patients. One hundred two patients were included; their average age was 53 years and 76% used it for more than a year preceding this study. Chronic pain (53%; n = 54) was the most common medical indication for using cannabis followed by multiple sclerosis (23%; n = 23), and 86% (n = 88) of patients (almost) always experienced therapeutic satisfaction when using pharmaceutical cannabis. Dejection, anxiety, and appetite stimulation were found to differ among the 3 strains of cannabis. These results show that patients report therapeutic satisfaction with pharmaceutical cannabis, mainly pain alleviation. Some subjective effects were found to differ among the available strains of cannabis, which is discussed in relation to their different tetrahydrocannabinol/cannabidiol content. These results may aid in further research and critical appraisal for medicinally prescribed cannabis products.
Angelucci, Francesco; Ricci, Valerio; Spalletta, Gianfranco; Pomponi, Massimiliano; Tonioni, Federico; Caltagirone, Carlo; Bria, Pietro
Chronic cannabis use produces effects within the central nervous system (CNS) which include deficits in learning and attention tasks and decreased brain volume. Neurotrophins, in particular nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF), are proteins that serve as survival factors for CNS neurons. Deficits in the production and utilization of these proteins can lead to CNS dysfunctions including those associated with cannabis abuse. In this study we measured by enzyme-linked immunosorbent assay (ELISA) the NGF and BDNF serum levels in two groups of subjects: cannabis-dependent patients and healthy subjects. We found that NGF serum levels were significantly reduced in cannabis abusers as compared to healthy subjects. These findings indicate that NGF may have a role in the central action of cannabis and potentially in the neurotoxicity induced by this drug. These data also suggest that chronic cannabis consumption may be a risk factor for developing psychosis among drug users.
Buckner, Julia D; Lemke, Austin W; Walukevich, Katherine A
Despite a documented relationship between cannabis use and suicidality, little is known about psychological vulnerability factors that may increase suicidality among this high-risk group. The Interpersonal-Psychological Theory of Suicide (IPTS; Joiner, 2005) proposes that people are vulnerable to wanting to die by suicide if they experience both perceived burdensomeness and thwarted belongingness. Daily cannabis users may be especially vulnerable to these factors. The current study used moderated mediation to test whether the relation between daily cannabis use status and suicidal ideation (SI) occurred indirectly via higher levels of both perceived burdensomeness and thwarted belongingness among 209 (76.1% female) current cannabis using undergraduates who used cannabis daily (n=39) or less frequently (n=160). The direct effect of cannabis use status on SI was no longer significant after controlling for thwarted belongingness, perceived burdensomeness, and the thwarted belongingness X perceived burdensomeness interaction. Cannabis use status was predictive of greater SI indirectly through perceived burdensomeness only at higher levels of thwarted belongingness. Findings support the utility of the IPTS in regard to SI among daily cannabis users, indicating that difficulties in interpersonal functioning may serve as potential pathways through which daily cannabis use may lead to greater suicide risk.
Lorenzetti, Valentina; Solowij, Nadia; Fornito, Alex; Lubman, Dan Ian; Yucel, Murat
Cannabis is the most widely used illicit drug worldwide, though it is unclear whether its regular use is associated with persistent alterations in brain morphology. This review examines evidence from human structural neuroimaging investigations of regular cannabis users and focuses on achieving three main objectives. These include examining whether the literature to date provides evidence that alteration of brain morphology in regular cannabis users: i) is apparent, compared to non-cannabis using controls; ii) is associated with patterns of cannabis use; and with iii) measures of psychopathology and neurocognitive performance. The published findings indicate that regular cannabis use is associated with alterations in medial temporal, frontal and cerebellar brain regions. Greater brain morphological alterations were evident among samples that used at higher doses for longer periods. However, the evidence for an association between brain morphology and cannabis use parameters was mixed. Further, there is poor evidence for an association between measures of brain morphology and of psychopathology symptoms/neurocognitive performance. Overall, numerous methodological issues characterize the literature to date. These include investigation of small sample sizes, heterogeneity across studies in sample characteristics (e.g., sex, comorbidity) and in employed imaging techniques, as well as the examination of only a limited number of brain regions. These factors make it difficult to draw firm conclusions from the existing findings. Nevertheless, this review supports the notion that regular cannabis use is associated with alterations of brain morphology, and highlights the need to consider particular methodological issues when planning future cannabis research.
McArdle, P A
A popular internet site describes cannabis as "a leafy plant, the leaves and flowering tops (buds) of which may be either smoked or eaten. It also comes in a more concentrated resinous form called hashish, and as a sticky black liquid called hash oil". It is said that users often report a pleasant "subjective enhancement of visual and auditory perception, sometimes with synaesthesia (sounds take on visual colourful qualities)" and the sense that time passes more quickly than real time, a "fatuous euphoria", as well as relaxation and relief from stress.
Bogart, Laura M.; Collins, Rebecca L.; Ellickson, Phyllis L.; Klein, David J.
The present study investigated whether adolescent cigarette, alcohol, marijuana, and hard drug use predicts life satisfaction in young adulthood. Survey data were used from a longitudinal cohort of 2376 adolescents at ages 18 and 29, originally recruited from California and Oregon middle schools at age 13. Results of multivariate models indicated…
Vaughn, Courtney; Long, Wesley
Investigates the uniqueness and complexity of adolescent drug and alcohol abuse recovery, particularly the early years and events catalyzing the surrender process. Offers individual interviews of seven adolescents who surrendered their alcohol and drug addictions and constructed sober identities through participation in Alcoholics Anonymous. (GCP)
Walker, Denise D.; Roffman, Roger A.; Stephens, Robert S.; Wakana, Kim; Berghuis, James
This study's aims were (a) to investigate the feasibility of a school-based motivational enhancement therapy (MET) intervention in voluntarily attracting adolescents who smoke marijuana regularly but who are not seeking formal treatment and (b) to evaluate the efficacy of the intervention in reducing marijuana use. Ninety-seven adolescents who had…
Brinson, Jesse A.
Examined African-American adolescents' use of alcohol and their perceptions of their family environments. Alcohol-using adolescents (n=71) completed Family Environment Scale (FES). Analyses of data revealed that females differed significantly from males on 4 of 10 FES subscales. Findings support view that alcohol affects perception of family…
Desrosiers, Nathalie A.; Ramaekers, Johannes G.; Chauchard, Emeline; Gorelick, David A.; Huestis, Marilyn A.
Δ9-Tetrahydrocannabinol (THC), the primary psychoactive constituent in cannabis, impairs psychomotor performance, cognition and driving ability; thus, driving under the influence of cannabis is a public safety concern. We documented cannabis' psychomotor, neurocognitive, subjective and physiological effects in occasional and frequent smokers to investigate potential differences between these smokers. Fourteen frequent (≥4x/week) and 11 occasional (<2x/week) cannabis smokers entered a secure research unit ∼19 h prior to smoking one 6.8% THC cigarette. Cognitive and psychomotor performance was evaluated with the critical tracking (CTT), divided attention (DAT), n-back (working memory) and Balloon Analog Risk (BART) (risk-taking) tasks at −1.75, 1.5, 3.5, 5.5 and 22.5 h after starting smoking. GLM (General Linear Model) repeated measures ANOVA was utilized to compare scores. Occasional smokers had significantly more difficulty compensating for CTT tracking error compared with frequent smokers 1.5 h after smoking. Divided attention performance declined significantly especially in occasional smokers, with session × group effects for tracking error, hits, false alarms and reaction time. Cannabis smoking did not elicit session × group effects on the n-back or BART. Controlled cannabis smoking impaired psychomotor function, more so in occasional smokers, suggesting some tolerance to psychomotor impairment in frequent users. These data have implications for cannabis-associated impairment in driving under the influence of cannabis cases. PMID:25745105
van Heugten-Van der Kloet, Dalena; Giesbrecht, Timo; van Wel, Janelle; Bosker, Wendy M; Kuypers, Kim P C; Theunissen, Eef L; Spronk, Desirée B; Jan Verkes, Robbert; Merckelbach, Harald; Ramaekers, Johannes G
Some drugs of abuse may produce dissociative symptoms, but this aspect has been understudied. We explored the dissociative potential of three recreational drugs (3,4-methylenedioxymethamphetamine (MDMA), cannabis, and cocaine) during intoxication and compared their effects to literature reports of dissociative states in various samples. Two placebo-controlled studies were conducted. In Study 1 (N=16), participants received single doses of 25, 50, and 100 mg of MDMA, and placebo. In Study 2 (N=21), cannabis (THC 300 µg/kg), cocaine (HCl 300 mg), and placebo were administered. Dissociative symptoms as measured with the Clinician-Administered Dissociative States Scale (CADSS) significantly increased under the influence of MDMA and cannabis. To a lesser extent, this was also true for cocaine. Dissociative symptoms following MDMA and cannabis largely exceeded those observed in schizophrenia patients, were comparable with those observed in Special Forces soldiers undergoing survival training, but were lower compared with ketamine-induced dissociation. Cocaine produced dissociative symptoms that were comparable with those observed in schizophrenia patients, but markedly less than those in Special Forces soldiers and ketamine users. Thus, MDMA and cannabis can produce dissociative symptoms that resemble dissociative pathology. The study of drug induced dissociation is important, because it may shed light on the mechanisms involved in dissociative psychopathology.
Jaques, S C; Kingsbury, A; Henshcke, P; Chomchai, C; Clews, S; Falconer, J; Abdel-Latif, M E; Feller, J M; Oei, J L
To review and summarise the literature reporting on cannabis use within western communities with specific reference to patterns of use, the pharmacology of its major psychoactive compounds, including placental and fetal transfer, and the impact of maternal cannabis use on pregnancy, the newborn infant and the developing child. Review of published articles, governmental guidelines and data and book chapters. Although cannabis is one of the most widely used illegal drugs, there is limited data about the prevalence of cannabis use in pregnant women, and it is likely that reported rates of exposure are significantly underestimated. With much of the available literature focusing on the impact of other illicit drugs such as opioids and stimulants, the effects of cannabis use in pregnancy on the developing fetus remain uncertain. Current evidence indicates that cannabis use both during pregnancy and lactation, may adversely affect neurodevelopment, especially during periods of critical brain growth both in the developing fetal brain and during adolescent maturation, with impacts on neuropsychiatric, behavioural and executive functioning. These reported effects may influence future adult productivity and lifetime outcomes. Despite the widespread use of cannabis by young women, there is limited information available about the impact perinatal cannabis use on the developing fetus and child, particularly the effects of cannabis use while breast feeding. Women who are using cannabis while pregnant and breast feeding should be advised of what is known about the potential adverse effects on fetal growth and development and encouraged to either stop using or decrease their use. Long-term follow-up of exposed children is crucial as neurocognitive and behavioural problems may benefit from early intervention aimed to reduce future problems such as delinquency, depression and substance use.
Background Cannabis is the most frequently used illicit substance in the United States resulting in high rates of cannabis use disorders. Current treatments for cannabis use are often met with high rates of lapse/relapse, tied to (1) behavioral health factors that impact cannabis use such as poor sleep, and (2) access, stigma, supply, and cost of receiving a substance use intervention. Objective This pilot study examined the feasibility, usability, and changes in cannabis use and sleep difficulties following mobile phone–delivered Cognitive Behavioral Therapy for Insomnia (CBT-I) in the context of a cannabis cessation attempt. Methods Four male veterans with DSM-5 cannabis use disorder and sleep problems were randomized to receive a 2-week intervention: CBT-I Coach mobile app (n=2) or a placebo control (mood-tracking app) (n=2). Cannabis and sleep measures were assessed pre- and post-treatment. Participants also reported use and helpfulness of each app. Changes in sleep and cannabis use were evaluated for each participant individually. Results Both participants receiving CBT-I used the app daily over 2 weeks and found the app user-friendly, helpful, and would use it in the future. In addition, they reported decreased cannabis use and improved sleep efficiency; one also reported increased sleep quality. In contrast, one participant in the control group dropped out of the study, and the other used the app minimally and reported increased sleep quality but also increased cannabis use. The mood app was rated as not helpful, and there was low likelihood of future participation. Conclusions This pilot study examined the feasibility and initial patient acceptance of mobile phone delivery of CBT-I for cannabis dependence. Positive ratings of the app and preliminary reports of reductions in cannabis use and improvements in sleep are both encouraging and support additional evaluation of this intervention. PMID:26187404
Elawad, Nagi; Misau, Yusuf A.; Shaikh, Tarteel M.; Allam, Nedal
Drug abuse is reported to be on the increase among young persons using illicit substances but little is known about the frequency with which they occur, the symptoms on presentation to health institutions, and the different substances abused. To establish this, we reviewed patient data collected at Al-Amal Hospital in Jeddah Kingdom of Saudi Arabia on young persons who are refered to the hospital for problems related to drug abuse. Data on 69 adolescent drug users were reviewed and analyzed using the Composite International Diagnostic Interview - Substance Abuse Model (CIDI-SAM) to assess dependence on substances including amphetamines, cannabis, cocaine, and opioids. Furthermore, we assessed the adolescents’ data on history of delusions and hallucinations in the context of use of, or withdrawal from, these specific substances. Our analysis shows that 10 to 79.6% of users of amphetamines, cannabis, cocaine, and opiates met DSM-III-R dependence criteria for each specific substance. The prevalence of psychotic symptoms associated with each specific substance ranged from users with no diagnosis to users with severe dependence as follows: amphetamines (3-100%), cannabis (7-60.0%), cocaine (5-70.7%), and opiates (4-88%). The risk of psychotic symptoms increased for respondents who abused (OR=7.2) or had mild (OR=8.1), moderate (OR=20.0), or severe dependence (OR=14.0) on cocaine when compared to those who were users with no diagnosis. A similar pattern was evident in cannabis, opiate, and amphetamine users. In conclusion, most adolescent drug users in Saudi Arabia who are dependent on illicit substances experience psychotic symptoms in the context of use of, or withdrawal from, these substances. Psychotic symptoms increased with the severity of the disorders associated with use of all four substances. These findings underscore the importance of developing services to target this population; a population at risk of developing psychotic symptoms. PMID:28299079
Thomas, Brian F.; Pollard, Gerald T.
Cannabis is classified as a schedule I controlled substance by the US Drug Enforcement Agency, meaning that it has no medicinal value. Production is legally restricted to a single supplier at the University of Mississippi, and distribution to researchers is tightly controlled. However, a majority of the population is estimated to believe that cannabis has legitimate medical or recreational value, numerous states have legalized or decriminalized possession to some degree, and the federal government does not strictly enforce its law and is considering rescheduling. The explosive increase in open sale and use of herbal cannabis and its products has occurred with widely variable and in many cases grossly inadequate quality control at all levels—growing, processing, storage, distribution, and use. This paper discusses elements of the analytical and regulatory system that need to be put in place to ensure standardization for the researcher and to reduce the hazards of contamination, overdosing, and underdosing for the end-user. PMID:27630566
Westfall, Rachel E; Janssen, Patricia A; Lucas, Philippe; Capler, Rielle
A majority of women experience some nausea and/or vomiting during pregnancy. This condition can range from mild nausea to extreme nausea and vomiting, with 1-2% of women suffering from the life-threatening condition hyperemesis gravidarum. Cannabis (Cannabis sativa) may be used therapeutically to mitigate pregnancy-induced nausea and vomiting. This paper presents the results of a survey of 84 female users of medicinal cannabis, recruited through two compassion societies in British Columbia, Canada. Of the seventy-nine respondents who had experienced pregnancy, 51 (65%) reported using cannabis during their pregnancies. While 59 (77%) of the respondents who had been pregnant had experienced nausea and/or vomiting of pregnancy, 40 (68%) had used cannabis to treat the condition, and of these respondents, 37 (over 92%) rated cannabis as 'extremely effective' or 'effective.' Our findings support the need for further investigations into cannabis therapy for severe nausea and vomiting during pregnancy.
Underner, M; Urban, T; Perriot, J; de Chazeron, I; Meurice, J-C
Cannabis is the most commonly smoked illicit substance in the world. It can be smoked alone in plant form (marijuana) but it is mainly smoked mixed with tobacco. The combined smoking of cannabis and tobacco is a common-place phenomenon in our society. However, its use is responsible for severe pulmonary consequences. The specific impact of smoking cannabis is difficult to assess precisely and to distinguish from the effect of tobacco. Marijuana smoke contains polycyclic aromatic hydrocarbons and carcinogens at higher concentration than tobacco smoke. Cellular, tissue, animal and human studies, and also epidemiological studies, show that marijuana smoke is a risk factor for lung cancer. Cannabis exposure doubles the risk of developing lung cancer. This should encourage clinicians to identify cannabis use and to offer patients support in quitting.
This review covers published information on psychoactive drugs, particularly cannabis, in Papua New Guinea. Legal drugs are mentioned to place the illegal drugs into a broader public health context. Although a number of psychoactive drugs were used traditionally (and are used now), cannabis is the only illicit drug for which prevalence of use is currently not negligible. Very little epidemiology research on cannabis use and its individual and public health sequelae has been conducted, although a fuller criminology literature on the topic exists. The published cannabis use prevalence studies are limited in scope, and the most-cited one is of questionable accuracy. The complex interactions between the health of individuals and their social environments are highlighted by the destructive impacts that cannabis cultivation, trafficking and use are having in contemporary PNG.
Troup, Lucy J.; Torrence, Robert D.; Andrzejewski, Jeremy A.; Braunwalder, Jacob T.
Abstract The effects of residual cannabis use on emotional expression recognition and the P3 event-related potential in participants who scored highly for subclinical depression were investigated. Comparisons were made between participants who were classified as depressed or nondepressed cannabis users, depressed non-cannabis users and controls who neither used cannabis nor were characterized as being depressed. In an emotional expression recognition task, participants were asked to respond to faces depicting happy, angry, fearful, and neutral faces either implicitly, explicitly, or empathically. Residual cannabis use and mood was shown to modulate the P3 event related potential during the task. There was a significant reduction in the P3 amplitude between depressed and nondepressed participants. Residual cannabis use further reduced the P3 amplitude with the greatest deficits being associated with cannabis users who scored highly for subclinical depression. These effects were greatest for explicit and empathic processing of faces depicting negative emotions. We conclude from our study that cannabis and mood state interact to reduce the amplitude of the P3 which has been associated with attention to emotion. PMID:28328830
Sethi, B.B.; Tiwari, S.C.; Kumar, Pradeep; Trivedi, J.K.
SUMMARY The Indian literature related to drug abuse in general and Cannabis in particular has been reviewed and possible implications discussed. In this regard to solve the existing controversy, 50 pure chronic cannabis users were evaluated for their physical, mental, cognitive and socio economic functions and the results were compared with a matched control group. Results of this study did not reveal any impairment in these areas It is concluded that cannabis, in India, may not be as much injurious to health as has often been mentioned in Western Countries. Future areas of research have been suggested. PMID:21965957
Compton, Michael T.; Broussard, Beth; Ramsay, Claire E.; Stewart, Tarianna
Introduction Limited research indicates that pre-illness cannabis use may result in an earlier age at onset of psychosis, though little is known about the influence of prior cannabis use on the premorbid and prodromal phases. This study examined effects of prior or concurrent cannabis (as well as nicotine and alcohol) use on: (1) early adolescent (12–15 years) premorbid functioning, (2) late adolescent (16–18 years) premorbid functioning, (3) two features of the prodrome, and (4) mode of onset of psychosis. Methods Participants included 109 well-characterized first-episode patients hospitalized in public-sector settings. Assessments included ages at initiation of first, weekly, and daily use of substances, the Premorbid Adjustment Scale, the Symptom Onset in Schizophrenia inventory, and a consensus-based best estimate of mode of onset. Results Participants having used cannabis at ≤15 years had better early adolescence social functioning than those who had not used cannabis (p=0.02). Conversely, those who had used cannabis at ≤18 years had poorer late adolescence academic functioning (p<0.001). Participants having used cannabis before onset of psychotic symptoms did not differ from those who had not in terms of having had an identifiable prodrome or the number of prodromal symptoms experienced. Whereas 42% of those having used cannabis daily had an acute mode of onset of psychosis, only 20% of those without prior daily cannabis use had an acute onset (p=0.04). Conclusions Findings suggest that cannabis use is associated with premorbid social and academic functioning and mode of onset. Further research is warranted to elucidate the complex associations between cannabis use and diverse early-course features. PMID:21036542
McDonald, A; Duncan, N D; Mitchell, D I
Sera from 111 patients with trauma injuries, who presented to the Accident and Emergency Unit (A&E), University Hospital of the West Indies, during a 3-month period, were screened for blood alcohol. Urine specimens were analysed for metabolites of cannabis and cocaine. Sixty-two per cent (62%) of patients were positive for at least one substance and 20% for two or more. Positivity rates were as follows: cannabis (46%), alcohol (32%) with 71% of these having blood alcohol levels (BAC) greater than 80 mg per decilitre; cocaine (6%). Substance usage was most prevalent in the third decade of life. The patients who yielded a positive result were significantly younger than those who were negative. There was no significant difference in age or substance usage between the victims of interpersonal violence or road traffic accidents. In the group designated "other accidents", patients were significantly older and had a lower incidence of substance usage than the other two groups. Cannabis was the most prevalent substance in all groups. Fifty per cent (50%) and fifty-five per cent (55%) of victims of road accidents and interpersonal violence, respectively, were positive for cannabis compared with 43% and 27% for alcohol, respectively. There was no significant difference in Hospital Stay or Injury Severity Score between substance users and non-users.
Booth, Judith K.; Page, Jonathan E.
Cannabis (Cannabis sativa) plants produce and accumulate a terpene-rich resin in glandular trichomes, which are abundant on the surface of the female inflorescence. Bouquets of different monoterpenes and sesquiterpenes are important components of cannabis resin as they define some of the unique organoleptic properties and may also influence medicinal qualities of different cannabis strains and varieties. Transcriptome analysis of trichomes of the cannabis hemp variety ‘Finola’ revealed sequences of all stages of terpene biosynthesis. Nine cannabis terpene synthases (CsTPS) were identified in subfamilies TPS-a and TPS-b. Functional characterization identified mono- and sesqui-TPS, whose products collectively comprise most of the terpenes of ‘Finola’ resin, including major compounds such as β-myrcene, (E)-β-ocimene, (-)-limonene, (+)-α-pinene, β-caryophyllene, and α-humulene. Transcripts associated with terpene biosynthesis are highly expressed in trichomes compared to non-resin producing tissues. Knowledge of the CsTPS gene family may offer opportunities for selection and improvement of terpene profiles of interest in different cannabis strains and varieties. PMID:28355238
ElSohly, Mahmoud A; Radwan, Mohamed M; Gul, Waseem; Chandra, Suman; Galal, Ahmed
Cannabis (Cannabis sativa, or hemp) and its constituents-in particular the cannabinoids-have been the focus of extensive chemical and biological research for almost half a century since the discovery of the chemical structure of its major active constituent, Δ(9)-tetrahydrocannabinol (Δ(9)-THC). The plant's behavioral and psychotropic effects are attributed to its content of this class of compounds, the cannabinoids, primarily Δ(9)-THC, which is produced mainly in the leaves and flower buds of the plant. Besides Δ(9)-THC, there are also non-psychoactive cannabinoids with several medicinal functions, such as cannabidiol (CBD), cannabichromene (CBC), and cannabigerol (CBG), along with other non-cannabinoid constituents belonging to diverse classes of natural products. Today, more than 560 constituents have been identified in cannabis. The recent discoveries of the medicinal properties of cannabis and the cannabinoids in addition to their potential applications in the treatment of a number of serious illnesses, such as glaucoma, depression, neuralgia, multiple sclerosis, Alzheimer's, and alleviation of symptoms of HIV/AIDS and cancer, have given momentum to the quest for further understanding the chemistry, biology, and medicinal properties of this plant.This contribution presents an overview of the botany, cultivation aspects, and the phytochemistry of cannabis and its chemical constituents. Particular emphasis is placed on the newly-identified/isolated compounds. In addition, techniques for isolation of cannabis constituents and analytical methods used for qualitative and quantitative analysis of cannabis and its products are also reviewed.
Zaleta, Sona; Kumar, Prashant; Miller, Sarah
“Legal highs” such as K2, which typically contain synthetic cannabinoids, are increasingly popular with adolescents around the world. We have limited knowledge concerning their toxicity or adverse effects and their mechanism of action is poorly understood. While synthetic cannabinoids have been linked to adverse cardiovascular effects, cases of ST-elevation myocardial infarction (STEMI) associated with K2 use are exceedingly rare. We report a case of a 14-year-old boy who suffered an STEMI after smoking K2. To our knowledge, this is not only the youngest case of an STEMI associated with K2 use, but also the first case to be reported outside of the United States of America. Pediatricians worldwide must be aware of the clinical significance and potential harm associated with the use of synthetic cannabinoids, to better educate patients and their families regarding the dangers of using such “legal” substances. PMID:27011700
Wrege, Johannes; Schmidt, André; Walter, Anna; Smieskova, Renata; Bendfeldt, Kerstin; Radue, Ernst-Wilhelm; Lang, Undine E.; Borgwardt, Stefan
We conducted a systematic review to assess the evidence for specific effects of cannabis on impulsivity, disinhibition and motor control. The review had a specific focus on neuroimaging findings associated with acute and chronic use of the drug and covers literature published up until May 2012. Seventeen studies were identified, of which 13 met the inclusion criteria; three studies investigated acute effects of cannabis (1 fMRI, 2 PET), while six studies investigated non-acute functional effects (4 fMRI, 2 PET), and four studies investigated structural alterations. Functional imaging studies of impulsivity studies suggest that prefrontal blood flow is lower in chronic cannabis users than in controls. Studies of acute administration of THC or marijuana report increased brain metabolism in several brain regions during impulsivity tasks. Structural imaging studies of cannabis users found differences in reduced prefrontal volumes and white matter integrity that might mediate the abnormal impulsivity and mood observed in marijuana users. To address the question whether impulsivity as a trait precedes cannabis consumption or whether cannabis aggravates impulsivity and discontinuation of usage more longitudinal study designs are warranted. PMID:23829358
Wrege, Johannes; Schmidt, Andre; Walter, Anna; Smieskova, Renata; Bendfeldt, Kerstin; Radue, Ernst-Wilhelm; Lang, Undine E; Borgwardt, Stefan
We conducted a systematic review to assess the evidence for specific effects of cannabis on impulsivity, disinhibition and motor control. The review had a specific focus on neuroimaging findings associated with acute and chronic use of the drug and covers literature published up until May 2012. Seventeen studies were identified, of which 13 met the inclusion criteria; three studies investigated acute effects of cannabis (1 fMRI, 2 PET), while six studies investigated non-acute functional effects (4 fMRI, 2 PET), and four studies investigated structural alterations. Functional imaging studies of impulsivity studies suggest that prefrontal blood flow is lower in chronic cannabis users than in controls. Studies of acute administration of THC or marijuana report increased brain metabolism in several brain regions during impulsivity tasks. Structural imaging studies of cannabis users found differences in reduced prefrontal volumes and white matter integrity that might mediate the abnormal impulsivity and mood observed in marijuana users. To address the question whether impulsivity as a trait precedes cannabis consumption or whether cannabis aggravates impulsivity and discontinuation of usage more longitudinal study designs are warranted.
Mather, Laurence E; Rauwendaal, Evert R; Moxham-Hall, Vivienne L; Wodak, Alex D
• After considering extensive scientific and medical evidence, a New South Wales Legislative Council multiparty committee recommended that medicinal cannabis should lawfully be made available for selected-use pharmacotherapy. • The evidence indicates that cannabis has genuine medicinal utility in patients with certain neuropathic conditions, with acceptable levels of risk from mostly mild side effects. • The potential medical benefits of cannabis pharmacotherapy have largely been overlooked, with research and society's attention, in most parts of the world, being directed towards the hazards of its recreational use. • The NSW Government has since dismissed the unanimous and compassionate recommendations of their committee.
Buchy, Lisa; Seidman, Larry J; Cadenhead, Kristin S; Cannon, Tyrone D; Cornblatt, Barbara A; McGlashan, Thomas H; Perkins, Diana O; Stone, William; Tsuang, Ming T; Walker, Elaine F; Woods, Scott W; Bearden, Carrie E; Mathalon, Daniel H; Addington, Jean
Among people with psychosis, those with a history of cannabis use show better cognitive performance than those who are cannabis naïve. It is unknown whether this pattern is present in youth at clinical high risk (CHR) of psychosis. We evaluated relationships between IQ and cannabis use while controlling for use of other substances known to impact cognition in 678 CHR and 263 healthy control (HC) participants. IQ was estimated using the Vocabulary and Block Design subtests of the Wechsler Abbreviated Scale of Intelligence. Drug and alcohol use severity and frequency were assessed with the Alcohol and Drug Use Scale, and we inquired participants' age at first use. CHR were further separated into early and late age at onset of cannabis use sub-groups, and low-, moderate- and high-frequency sub-groups. No significant differences in IQ emerged between CHR or HC cannabis users vs. non-users, or between use frequency groups. CHR late-onset users showed significantly higher IQ than CHR early-onset users. Age at onset of cannabis use was significantly and positively correlated with IQ in CHR only. Results suggest that age at onset of cannabis may be a more important factor for IQ than use current use or use frequency in CHR.
There is a high comorbidity between cannabis use and schizophrenia. Several factors contribute to this comorbidity: secondary development of addiction, cannabis-related induction of psychosis and shared neurobiological alterations. Meanwhile, there is evidence that cannabis use is associated with an increased risk of schizophrenia. Prospective epidemiological studies have shown that a frequent cannabis use doubles the risk for schizophrenia. Interestingly, schizophrenic patients with comorbid cannabis use often show significantly better performances in neuropsychological tests than patients without cannabis use. This is nevertheless not due to a positive effect of cannabis, but a sign of cannabis-related psychosis induction in subjects with a higher level of function and less cognitive impairment. Whether cannabis use leads to schizophrenia is determined by the individual vulnerability.
Svedin, Carl Goran; Akerman, Ingrid; Priebe, Gisela
Frequent use of pornography has not been sufficiently studied before. In a Swedish survey 2015 male students aged 18 years participated. A group of frequent users of pornography (N = 200, 10.5%) were studied with respect to background and psychosocial correlates. The frequent users had a more positive attitude to pornography, were more often…
Budney, Alan J; Vandrey, Ryan G; Hughes, John R; Thostenson, Jeff D; Bursac, Zoran
This naturalistic telephone survey study compared perceptions of withdrawal severity in 67 daily cannabis users and 54 daily tobacco cigarette smokers who made quit attempts during the prior 30 days. A Withdrawal Symptom Checklist assessed the severity of abstinence symptoms and a Likert scale assessed perceived relations between abstinence symptoms and relapse. A composite Withdrawal Discomfort Score did not differ significantly between groups (M = 13.0 for cannabis, vs. M = 13.2 for tobacco). Individual symptom severity ratings were also of similar magnitude, except craving and sweating were slightly higher for tobacco. Both groups reported that withdrawal contributed substantially to relapse, and the strength of these ratings was similar across groups. The diverse convenience sample examined in this study adds external validity and generalizability to prior studies that included only users not planning to quit or excluded many common types of cannabis users. The comparable withdrawal experience from these heterogeneous cannabis and tobacco users supports previous findings from controlled laboratory studies and indicates that real-world, frequent cannabis users perceive that withdrawal symptoms negatively affect their desire and ability to quit.
Otten, Roy; Engels, Rutger C M E
Evidence for the assumption that cannabis use is associated with depression and depressive symptoms is inconsistent and mostly weak. It is likely that the mixed results are due to the fact that prior studies ignored the moderating effects of an individual's genetic vulnerability. The present study takes a first step in scrutinizing the relationship between cannabis use and depressive symptoms by taking a developmental molecular-genetic perspective. Specifically, we concentrated on changes in cannabis use and depressive symptoms over time in a simultaneous manner and differences herein for individuals with and without the short allele of the 5-hydroxytryptamine (serotonin) transporter gene-linked polymorphic region (5-HTTLPR) genotype. Data were from 310 adolescents over a period of 4 years. We used a parallel-process growth model, which allows co-development of cannabis use and depressive symptoms throughout adolescence, and the possible role of the 5-HTTLPR genotype in this process. We used data from the younger siblings of these adolescents in an attempt to replicate potential findings. The parallel-process growth model shows that cannabis use increases the risk for an increase in depressive symptoms over time but only in the presence of the short allele of the 5-HTTLPR genotype. This effect remained significant after controlling for covariates. We did not find conclusive support for the idea that depressive symptoms affect cannabis use. These findings were replicated in the sample of the younger siblings. The findings of the present study show first evidence that the links between cannabis use and depressive symptoms are conditional on the individual's genetic makeup.
... and neurologic variables, underwent functional magnetic resonance imaging (fMRI, which measures patterns of brain activity during performance of a task) while completing a test of working memory. The cannabis group performed more poorly on the ...
Mason, Michael; Light, John; Campbell, Leah; Keyser-Marcus, Lori; Crewe, Stephanie; Way, Thomas; Saunders, Heather; King, Laura; Zaharakis, Nikola M; McHenry, Chantal
Close peer networks can affect adolescents' health behaviors by altering their social environments, and thus their risk for and protection against substance use involvement. We tested a 20 minute intervention named Peer Network Counseling that integrates motivational interviewing and peer network strategies with 119 urban adolescents who reported occasional or problem substance use. Adolescents presenting at primary care clinic were randomized to intervention or control conditions and followed for 6 months. Mixed-effect latent growth models were used to evaluate intervention effects on trajectories of alcohol and marijuana use, offers to use substances, and moderation models to test for interactions between intervention condition and peer network characteristics. A significant intervention effect was found for boys for offers to use alcohol from friends (p<.05), along with a trend significant effect for alcohol use (p<.08). Intervention was more effective in reducing marijuana use, vs. control, for participants with more peer social support (p<.001) and with more peer encouragement for prosocial behavior (school, clubs, sports, religious activities); however, intervention did not affect these network characteristics. Results provide support to continue this line of research to test brief interventions that activate protective peer network characteristics among at-risk adolescents, while also raising some interesting gender-based intervention questions for future research.
Tait, Robert J.; Hulse, Gary K.
The objectives were, firstly, to describe the frequency and type of hospital emergency department (ED) admissions in a small number of alcohol and other drug (AOD) using adolescents who accounted for a high number of ED and other hospital presentations. Secondly, to identify interventions that impacted on these repeat ED presentations. An earlier…
Gallagher, Jen; Schlösser, Annette
Ten per cent of young people experience mental health difficulties at any one time. Prevention and early intervention leads to better prognosis for young people's mental well-being in the short and long term. Child and Adolescent Mental Health Services (CAMHS) must be able to provide swift and effective interventions for a range of difficulties to…
Berk, Lotte; Stewart, Jennifer L.; May, April C.; Wiers, Reinout W.; Davenport, Paul W.; Paulus, Martin P.; Tapert, Susan F.
Background and Aims Adolescents with substance use disorders (SUD) exhibit hyposensitivity to pleasant internally generated (interoceptive) stimuli and hypersensitivity to external rewarding stimuli. It is unclear whether similar patterns exist for aversive interoceptive stimuli. We compared activation in the insular cortex and other brain regions during the anticipation and experience of aversive stimuli between adolescents with SUD and those without. Design and participants Cross-sectional experimental study with two groups: Adolescents (ages 15–17) with an alcohol or marijuana SUD (n=18) and healthy comparison subjects (CON, n=15). Participants were recruited by distributing flyers at local high schools. Setting Keck Imaging Center, University of California San Diego, USA. Measurements Behavioral and neural responses to a continuous performance task with inspiratory breathing load recorded during an fMRI session. Questionnaires assessed lifetime drug use, anxiety, sensation seeking, impulsivity, affect, and bodily awareness. Visual analogue scales assessed drug craving and breathing load responses. Findings Across subjects, experience of breathing load elicited greater bilateral anterior and posterior insula (AI and PI, respectively) activation than anticipation (F(1,31)=4.16, p<.05). SUD exhibited greater left AI and bilateral PI activation during breathing load than anticipation, compared with CON (F(1,31)=4.16, p<.05). In contrast, CON showed greater activation during anticipation than breathing load in left PI, compared with SUD (F(1,31)=4.16, p<.05). Conclusions Adolescents with alcohol and marijuana substance use disorders may be hypersensitive to aversive interoceptive stimuli. PMID:26234745
Analysis of data on 1,121 older adolescents and young adults from a national longitudinal survey examined effects of community involvement, social satisfaction, social network size, race, gender, and age on use of alcohol, marijuana, and cocaine. Social support did influence use of alcohol and other drugs, but the direction of influence varied by…
Feingold, Daniel; Rehm, Jürgen; Lev-Ran, Shaul
Cannabis use has been reported to affect the course of various psychiatric disorders, however its effect on the course of major depressive disorder (MDD) is not yet clear. We used data from Wave 1 and Wave 2 of the National Epidemiologic survey on Alcohol and Related Conditions (NESARC). Individuals with baseline MDD (N=2,348) were included in the study. Cannabis users without a Cannabis Use Disorder (CUDs) and individuals with a CUD were compared to nonusers using linear and logistic regression analyses controlling for sociodemographics, psychiatric disorders and substance use disorders at baseline. No differences were found in rates of remission between the groups. Level of cannabis use was associated with significantly more depressive symptoms at follow-up, particularly anhedonia, changes in body weight, insomnia or hypersomnia and psychomotor problems. After adjusting for baseline confounding factors, no associations were found between cannabis use and suicidality, functionality and quality of life. We conclude that many of the associations between cannabis use and a more severe course of MDD do not seem to be attributed to cannabis use itself but to associated sociodemographic and clinical factors. Further longitudinal studies using depression severity indices are required.
Perron, Brian E.; Bohnert, Kipling; Perone, Angela K.; Bonn-Miller, Marcel O.; Ilgen, Mark
Objective: Management of chronic pain is one of the most common reasons given by individuals seeking medical cannabis. However, very little information exists about the concurrent use of cannabis and prescription pain medication (PPM). This study fills this gap in knowledge by systematically comparing medical cannabis users who use or do not use PPM, with an emphasis on understanding whether concurrent use of cannabis and PPM is associated with more serious forms of alcohol and other drug involvement. Method: Data from this study were collected from a medical cannabis clinic in southwestern Michigan (N = 273). Systematic comparisons were made on measures of sociodemographics, reasons for substance use, pain, functioning, and perceptions of PPM and medical cannabis efficacy. Results: PPM users tended to be older and reported higher levels of pain and lower levels of functioning. The overall sample exhibited higher lifetime and past-3-month rates of alcohol and other noncannabis drug use than did the general population. Approximately 40% of subjects reported combining cannabis with alcohol, but no significant difference was observed between PPM users and nonusers. PPM users and nonusers did not exhibit any difference in either lifetime or past-3-month use of other drugs, including cocaine, sedatives, street opioids, and amphetamines. PPM users rated the efficacy of cannabis higher than PPM for pain management and indicated a strong desire to reduce PPM usage. Conclusions: Use of PPM among medical cannabis users was not identified as a correlate for more serious forms of alcohol and other drug involvement. However, longitudinal study designs are needed to better understand the trajectories of alcohol and other drug involvement over time among medical cannabis users. PMID:25978826
Trezza, Viviana; Cuomo, Vincenzo; Vanderschuren, Louk J M J
The isolation and identification, in 1964, of delta-9-tetrahydrocannabinol (THC), the primary psychoactive compound in cannabis, opened the door to a whole new field of medical research. The exploration of the therapeutic potential of THC and other natural and synthetic cannabinoid compounds was paralleled by the discovery of the endocannabinoid system, comprising cannabinoid receptors and their endogenous ligands, which offered exciting new insights into brain function. Besides its well-known involvement in specific brain functions, such as control of movement, memory and emotions, the endocannabinoid system plays an important role in fundamental developmental processes such as cell proliferation, migration and differentiation. For this reason, changes in its activity during stages of high neuronal plasticity, such as the perinatal and the adolescent period, can have long-lasting neurobehavioral consequences. Here, we summarize human and animal studies examining the behavioral and neurobiological effects of in utero and adolescent exposure to cannabis. Since cannabis preparations are widely used and abused by young people, including pregnant women, understanding how cannabinoid compounds affect the developing brain, leading to neurobehavioral alterations or neuropsychiatric disorders later in life, is a serious health issue. In addition, since the endocannabinoid system is emerging as a novel therapeutic target for the treatment of several neuropsychiatric diseases, a detailed investigation of possible adverse effects of cannabinoid compounds on the central nervous system (CNS) of immature individuals is warranted.
Feeney, Mistianne; Punja, Zamir K
Hemp (Cannabis sativa L.) suspension culture cells were transformed with Agrobacterium tumefaciens strain EHA101 carrying the binary plasmid pNOV3635. The plasmid contains a phosphomannose isomerase (PMI) selectable marker gene. Cells transformed with PMI are capable of metabolizing the selective agent mannose, whereas cells not expressing the gene are incapable of using the carbon source and will stop growing. Callus masses proliferating on selection medium were screened for PMI expression using a chlorophenol red assay. Genomic DNA was extracted from putatively transformed callus lines, and the presence of the PMI gene was confirmed using PCR and Southern hybridization. Using this method, an average transformation frequency of 31.23% ± 0.14 was obtained for all transformation experiments, with a range of 15.1-55.3%.
Feeney, Mistianne; Punja, Zamir K
Hemp (Cannabis sativa L.) suspension culture cells were transformed with Agrobacterium tumefaciens strain EHA101 carrying the binary plasmid pNOV3635. The plasmid contains a phosphomannose isomerase (PMI) selectable marker gene. Cells transformed with PMI are capable of metabolizing the selective agent, mannose, whereas cells not expressing the gene are incapable of using the carbon source and will stop growing. Callus masses proliferating on selection were screened for PMI expression using a chlorophenol red assay. Genomic DNA was extracted from putatively transformed callus lines and the presence of the PMI gene was confirmed using polymerase chain reaction and Southern hybridization. Using this method, an average transformation frequency of 31.23% +/- 0.14 was obtained for all transformation experiments, with a range of 15.1 to 55.3%.
Honarmand, Kimia; Tierney, Mary C.; O'Connor, Paul
Background: While neuropsychological deficits have been reported in healthy individuals who use street cannabis, data in patients with multiple sclerosis (MS) are lacking. Given that MS is associated with cognitive deterioration, the aim of this study was to determine the neuropsychological effects of cannabis use in this population. Methods: Two groups, each of 25 patients with MS (cannabis users and nonusers), were administered the Minimal Assessment of Cognitive Function in MS battery of neuropsychological tests, the Hospital Anxiety and Depression Scale (HADS), and the Structured Clinical Interview for the DSM-IV Axis I Disorders (SCID-I). Group-matching and regression analysis were used to control for the effects of age, sex, education, premorbid intelligence, disability, and disease course and duration on cognitive function. Results: Cannabis users performed significantly more poorly than nonusers on measures of information processing speed, working memory, executive functions, and visuospatial perception. They were also twice as likely as nonusers to be classified as globally cognitively impaired. There were no between-group differences on the HADS measures of depression and anxiety or lifetime SCID-I psychiatric diagnoses. Conclusion: This cross-sectional study provides empirical evidence that prolonged use of inhaled or ingested street cannabis in patients with MS is associated with poorer performance on cognitive domains commonly affected in this population. Whatever subjective benefits patients may derive from using street cannabis (e.g., pain and spasticity relief) should be weighed against the associated cognitive side effects. PMID:21444900
Garcia, Grey Yuliet Ceballos; Santos, Darci Neves; Machado, Daiane Borges
Few Brazilian studies have addressed the use of mental health services for children and adolescents. This study aimed to characterize the national distribution of Psychosocial Care Centers for Children and Adolescents (CAPSi) and describe the patient profile in this age group between 2008 and 2012. An ecological study was carried out, using records from the Authorizations for High-Complexity Procedures (APAC) system and the Brazilian National Registry of Healthcare Organizations (CNES). Socio-demographics and disease profile were analyzed. In 2014, 208 CAPSi were recorded in the CNES, distributed across 23 of Brazil's 27 states. Treatments included predominantly behavioral disorders (29.7%), developmental disorders (23.6%), and mental retardation (12.5%). CAPSi are insufficient and unequally distributed. The disease profile suggests the need for linkage between specialized mental health services and primary care, in addition to the inclusion of inter-sector work.
Nicholls, Clare; Bruno, Raimondo; Matthews, Allison
The aim of the study was to investigate the relationship between chronic cannabis use and visual selective attention by examining event-related potentials (ERPs) during the performance of a flanker go/nogo task. Male participants were 15 chronic cannabis users (minimum two years use, at least once per week) and 15 drug naive controls. Cannabis users showed longer reaction times compared to controls with equivalent accuracy. Cannabis users also showed a reduction in the N2 'nogo effect' at frontal sites, particularly for incongruent stimuli, and particularly in the right hemisphere. This suggests differences between chronic cannabis users and controls in terms of inhibitory processing within the executive control network, and may implicate the right inferior frontal cortex. There was also preliminary evidence for differences in early selective attention, with controls but not cannabis users showing modulation of N1 amplitude by flanker congruency. Further investigation is required to examine the potential reversibility of these residual effects after long-term abstinence and to examine the role of early selective attention mechanisms in more detail.
Chruściel, T L
Rapid increase in our knowledge of acute biological effects of cannabis and its biologically active components is contrasted with the slow rate of progress achieved in the area of effects of long-term use of cannabis in man. Such studies belong to the difficult category of long-term clinical pharmacological studies, that are time-consuming, require large population samples, and considerable expertise of staff. Recently published epidemiological studies on effects of long-term cannabis use, although still not yet conclusive, supply increasing evidence of harmful effects of such use. Recently, the World Health Organization has sponsored several research projects of this nature in countries with easy access to long-term heavy cannabis users.
Patten, Christi A.; Enoch, Carrie; Renner, Caroline C.; Offord, Kenneth P.; Nevak, Caroline; Kelley, Stacy F.; Thomas, Janet; Decker, Paul A.; Hurt, Richard D.; Lanier, Anne; Kaur, Judith S.
Tobacco cessation interventions developed for Alaska Native adolescents do not exist. This study employed focus group methodology to explore preferences for tobacco cessation interventions and barriers to participation among 49 Alaska Natives (61% female) with a mean age of 14.6 (SD = 1.6) who resided in western Alaska. Using content analysis, themes from the 12 focus groups were found to be consistent across village, gender, and age groups. Program location or site (e.g., away from the village, hunting, fishing), a group-based format, and inclusion of medication and personal stories were reported to be important attributes of cessation programs. Motivators to quit tobacco were the perceived adverse health effects of tobacco, improved self-image and appearance, and the potential to be a future role model as a non–tobacco user for family and friends. Parents were perceived as potentially supportive to the adolescent in quitting tobacco. The findings will be used to develop tobacco cessation programs for Alaska Native youth. PMID:18048549
Durdle, Heather; Lundahl, Leslie H; Johanson, Chris-Ellyn; Tancer, Manuel
Previous research has suggested that 3,4-methylenedioxymethamphetamine (MDMA; ecstasy) users have elevated depressive symptomatology, although it is not clear whether this is due to MDMA or other drug use. This study aimed to investigate the contributions of MDMA and cannabis use to Major Depressive Disorder in MDMA users. A total of 226 MDMA users were studied. Participants (65% male) reported an average number of 35.8 uses of MDMA (SD = 45.6, range = 2-400). Participants were administered a Structured Clinical Interview for DSM-IV. Twenty-six individuals (11.5%) met lifetime criteria for Major Depressive Disorder. High rates of lifetime Cannabis Abuse (30.1%) and Cannabis Dependence (12.4%) were reported. No association was found between number of uses of MDMA and Major Depressive Disorder. Those with lifetime major depression were found, however, to have higher rates of lifetime cannabis use disorder (adjusted OR = 2.40). A logistic regression indicated that lifetime cannabis use disorder, but not MDMA use, was significantly associated with lifetime Major Depressive Disorder. Stratified analyses suggested that for males, neither drug use variable was associated with major depression. For females, a lifetime cannabis use disorder (adjusted OR = 4.99), but not MDMA use, was associated with lifetime Major Depressive Disorder. Results of this study suggest that although MDMA use was not found to be significantly associated with major depression for either gender, a lifetime cannabis use disorder was significantly associated with lifetime major depression for female, but not male, users of MDMA.
Caulkins, Jonathan P
The U.S. appears to be on a path toward legalizing cannabis on the alcohol model, which is to say allowing for-profit corporations to produce, sell, and promote its use. Even after national legalization, it will take decades to observe the full effects on industry structure and behavior, or on use and misuse. However, we should not be surprised if after markets have matured and consumption patterns stabilized, legalization increases acute cannabis intoxication in the U.S. by 40 billion hours per year. This increase in use will be the most important cannabis-specific effect of legalization. The bulk of it will be consumption by daily and near-daily users, and it is possible that roughly half will be by people who meet the medical criteria for substance use disorder. Much resulting harms will be borne by the users, and their families, and the harms are not primarily "medical", at least not in the narrow sense. Hence, legalization replaces the current problems of crime and black markets not so much with a medical or public health problem, but rather with a problem of potentially excessive consumption of a "temptation good" whose acute effects are performance degrading, not performance-enhancing. As legalization removes formal social controls, it might be prudent for society to develop stronger informal social norms - akin to "friends don't let friends drive drunk" - to protect the public and more importantly the users themselves from the performance degradation of bouts of nearly perpetual intoxication.
The UK has the highest rate of cannabis use among young people worldwide. Dr. Alan Leshner, Director of the National Institute of Drug Abuse reports, "Every year more than 100,000 people, most of them adolescents, seek treatment for their inability to control their marijuana use." According to the Scottish Drug Misuse Statistics in…
Svedin, Carl Göran; Akerman, Ingrid; Priebe, Gisela
Frequent use of pornography has not been sufficiently studied before. In a Swedish survey 2015 male students aged 18 years participated. A group of frequent users of pornography (N = 200, 10.5%) were studied with respect to background and psychosocial correlates. The frequent users had a more positive attitude to pornography, were more often "turned on" viewing pornography and viewed more often advanced forms of pornography. Frequent use was also associated with many problem behaviours. A multiple logistic regression analysis showed that frequent users of pornography were more likely to be living in a large city, consuming alcohol more often, having greater sexual desire and had more often sold sex than other boys of the same age. High frequent viewing of pornography may be seen as a problematic behaviour that needs more attention from both parents and teachers and also to be addressed in clinical interviews.
Rieder, Michael J
Cannabis is a psychoactive compound with a long history of recreational and therapeutic use. Current considerations regarding cannabis use for medical purposes in children have been stimulated by recent case reports describing its beneficial effect with refractory epilepsy. Overall, there are insufficient data to support either the efficacy or safety of cannabis use for any indications in children, and an increasing body of data suggests possible harm, most importantly in specific conditions. The potential for cannabis as a therapeutic agent must be evaluated carefully for both efficacy and safety in treating specific paediatric health conditions. Smoking is not an acceptable mode of drug delivery for children. The use of cannabis for medical purposes in specific cases should not be construed as a justification for recreational cannabis use by adolescents. Recommendations for therapeutic use in exceptional paediatric cases are offered, always providing that this treatment course is carefully evaluated in individuals and in ongoing, well-designed research studies to determine safety and efficacy. PMID:26941559
Jonsson, Arnar Jan; Birgisdottir, Hera; Sigurdsson, Engilbert
Over the past 30 years evidence has been growing that cannabis use increases the risk for psychosis which could develop into schizophrenia in a proportion of cases. Over the past decade many studies have been published which clarify the association between cannabis use and psychosis. The aim of this review is to examine this association. A systematic search yielded 14 cohort studies carried out in 9 cohorts and 9 case-control studies. When the results of these studies are taken together they unambiguously support that cannabis use is an independent risk factor for psychosis and may also give rise to chronic psychotic disorders like schizophrenia. A dose dependent link is present because more frequent use associates with greater risk. The studies also show that cannabis-use in adolescence is associated with greater risk of developing psychosis than commencing the use of cannabis in adulthood. Further studies are needed to explain this association since psychotic disorders take years to evolve and it remains difficult to measure both the explanatory and the response variable and their complex relationship. The results emphasize the need to enhance public knowledge on the possible consequences of cannabis use and the fact that it cannot be predicted who will experience transient psychosis and who will develop a chronic psychotic disorder.
Fischer, Benedikt; Kuganesan, Sharan; Room, Robin
While prohibition has been the dominant regime of cannabis control in most countries for decades, an increasing number of countries have been implementing cannabis control reforms recently, including decriminalization or even legalization frameworks. Canada has held out from this trend, although it has among the highest cannabis use rates in the world. Cannabis use is universally criminalized, and the current (conservative) federal government has vowed not to implement any softening reforms to cannabis control. As a result of several higher court decisions, the then federal government was forced to implement a 'medical marijuana access regulations' program in 2001 to allow severely ill patients therapeutic use and access to therapeutic cannabis while shielding them from prosecution. The program's regulations and approval processes were complex and subject to extensive criticism; initial uptake was low and most medical marijuana users continued their use and supply outside the program's auspices. This year, the government introduced new 'marijuana for medical purposes regulations', which allow physicians to 'authorize' medical marijuana use for virtually any health condition for which this is considered beneficial; supply is facilitated by licensed commercial producers. It is expected that some 500,000 users, and dozens of commercial producers will soon be approved under the program, arguably constituting - as with medical marijuana schemes elsewhere, e.g. in California--de facto 'legalization'. We discuss the question whether the evolving scope and realities of 'medical cannabis' provisions in Canada offer a 'sneaky side door' or a 'better third way' to cannabis control reform, and what the potential wider implications are of these developments.
Lee, Dustin C.; Budney, Alan J.; Brunette, Mary F.; Hughes, John R.; Etter, Jean-Francois; Stanger, Catherine
BACKGROUND Cannabis users frequently report concurrent tobacco use, and tobacco use is associated with poorer outcomes during treatment for cannabis use disorders (CUD). Interventions that simultaneously target both tobacco and cannabis use disorders may enhance cessation outcomes for either or both substances. METHODS This study evaluated an intervention integrating highly effective treatments for cannabis and tobacco use disorders. Thirty-two participants meeting diagnostic criteria for CUD and reporting daily tobacco use were enrolled in a 12-week computer-assisted behavioral treatment for CUD. Participants were encouraged to participate in a tobacco intervention that included a computer-assisted behavioral treatment tailored for tobacco and cannabis co-users, and nicotine-replacement therapy (NRT). Cannabis and tobacco outcomes were evaluated using descriptive statistics and were compared to a historical control group that received treatment for CUD but not tobacco. RESULTS Participants achieved 3.6 ± 4.3 consecutive weeks of cannabis abstinence, which was comparable to the historical control group (3.1 ± 4.4). A majority of the sample (78%) completed at least one tobacco module and 44% initiated NRT. Over half (56%) initiated tobacco quit attempts, and 28% were tobacco abstinent for at least two consecutive weeks. Participants showed greater reduction in tobacco use (cigarettes per day) than the historical control group, but differences in tobacco abstinence rates during the final month of treatment were not statistically significant (12.5% vs 4%). CONCLUSION Findings suggest that providing a tobacco intervention during treatment for CUD is feasible and may positively impact tobacco use without negatively affecting cannabis use outcomes. PMID:26307942
Wetherill, Reagan R; Jagannathan, Kanchana; Hager, Nathan; Childress, Anna Rose; Franklin, Teresa R
Preclinical and clinical research indicates that there are sex differences in how men and women initiate, progress, respond to, and withdraw from cannabis use; however, neurophysiological differences, such as neural responses to cannabis cues, are not well understood. Using functional MRI and an event-related blood oxygen level-dependent backward-masking task, we compared neural responses to backward-masked cannabis cues to neutral cues in treatment-seeking, cannabis-dependent adults (N = 44; 27 males) and examined whether sex differences exist. In addition, functional MRI findings were correlated with cannabis craving. Backward-masked cannabis cues elicited greater neural responses than neutral cues in reward-related brain regions, including the striatum, hippocampus/amygdala, insula, anterior cingulate cortex, and lateral orbitofrontal cortex, p < .01, k > 121 voxels. Although no significant sex differences in neural responses to cannabis cues emerged, women showed a positive correlation between neural responses to cannabis cues in the bilateral insula and cannabis craving and an inverse correlation between neural responses to cannabis cues in the left lateral orbitofrontal cortex and cannabis craving. Men, however, showed a positive correlation between neural responses to cannabis cues in the striatum and cannabis craving. Given that cues and craving are important triggers and the focus on many behavioral treatment approaches, these findings suggest that treatment-seeking, cannabis-dependent men and women may benefit from sex-specific and tailored cannabis use disorder treatments.
Szoke, Andrei; Galliot, Anne-Marie; Richard, Jean-Romain; Ferchiou, Aziz; Baudin, Grégoire; Leboyer, Marion; Schürhoff, Franck
Cannabis consumption can cause abuse and dependence and increase risk of developing psychiatric and somatic disorders. Several literature reviews explored the link between cannabis consumption and schizophrenia but none summarized the rich literature on cannabis and psychometric schizotypy. The aim of our review is to synthesize data from studies that explored the association between cannabis consumption and schizoptypal dimensions. A systematic review of the literature and, when needed, contact with the authors, allowed us to gather data from 29 cross-sectional studies. We compared schizotypy scores between subjects that never used cannabis and subjects that used it at least once ("never vs. ever") and between current users and subjects that do not use cannabis currently ("current vs. other"). We conducted separate analyses for total schizotypy score and each of the three classical schizotypal dimensions (positive, negative, disorganized). For all eight comparisons, the cannabis group ("ever" or "current") had higher schizotypy scores. Differences were in the small or medium range and, with the exception of the negative score in the current vs. other comparison, statistically significant. Cannabis consumption is associated with increased schizotypal traits. More research, using different approaches (e.g. longitudinal studies) is needed to explore the cause of this association.
Newton-Howes, Giles; McBride, Sam
There has been increased interest in cannabis as a medicine both nationally and internationally. Internationally, cannabis is accepted as a medication for a variety of purposes in a variety of legal guises and this, associated with anecdotes of the utility of cannabis as medication has led for calls for it to be 'medicalised' in New Zealand. This viewpoint discusses the issues associated with this approach to accessing cannabis and some of the difficulties that may be associated with it. It is important doctors are at the forefront of the debate surrounding medicalised cannabis. Recommendations as to the ongoing debate are offered.
Huestis, Marilyn A.; Mazzoni, Irene; Rabin, Olivier
Since 2004, when the World Anti-Doping Agency assumed the responsi-bility for establishing and maintaining the list of prohibited substances and methods in sport (i.e. the Prohibited List), cannabinoids have been prohibited in all sports during competition. The basis for this prohibition can be found in the World Anti-Doping Code, which defines the three criteria used to consider banning a substance. In this context, we discuss the potential of can-nabis to enhance sports performance, the risk it poses to the athlete’s health and its violation of the spirit of sport. Although these compounds are prohibited in-competition only, we explain why the pharmacokinetics of their main psychoactive compound, Δ9-tetrahydrocannabinol, may complicate the results management of adverse analytical findings. Passive inhalation does not appear to be a plausible explanation for a positive test. Although the prohibition of cannabinoids in sports is one of the most controversial issues in anti-doping, in this review we stress the reasons behind this prohibition, with strong emphasis on the evolving knowledge of cannabinoid pharmacology. PMID:21985215
Pérez De La Barrera, Citlalli
A cross-sectional study was carried out with the purpose of validating seven life skills scales reported in the literature as related to drug-abuse prevention, and which identify differences between these skills among non-user adolescent students and users of alcohol, tobacco, cannabis and inhalants. The sample was made up of 425 adolescents, 196 (46.1%) male and 229 (53.9%) female. These participants were randomly selected from a private high school in the state of Morelos, and their mean age was 15.8 years, with a standard deviation of 1.97. To measure skills we used the scales validated in this survey, while patterns of drug use were measured with a scale based on the National Addiction Survey (2008) indicators. Results showed that students who did not use alcohol, tobacco, cannabis or inhalants scored higher in skills of empathy, future orientation and peer pressure resistance, compared to those who had used these substances in the last month. On the basis of these findings it would seem necessary to develop drug-abuse prevention programs for high school students based on a life skills training approach.
Weiss, Susan R B; Howlett, Katia D; Baler, Ruben D
Social attitudes and cultural norms around the issue of substance abuse are shifting rapidly around the world, leading to complex and unpredictable consequences. On the positive side, efforts to more intensely disseminate the scientific evidence for the many connections between chronic substance use and the emergence of measurable and discrete brain dysfunctions, has ushered in an evolving climate of acceptance and a new era of improved access to more effective interventions, at least in the United States. On the negative side, there has been a steady erosion in the public perception of the harms associated with the use of popular drugs, especially cannabis. This worrisome trend has sprouted at the convergence of several forces that have combined, more or less fortuitously, to effectively change long-standing policies away from prohibition and toward decriminalization or legalization. These forces include the outsized popularity of the cannabis plant among recreational users, the unflagging campaign by corporate lobbyists and patient advocates to mainstream its medicinal use, and the honest realization in some quarters of the deleterious impact of the drug war and its draconian cannabis laws, in particular, on society's most vulnerable populations. Updating drug policies is a desirable goal, and significant changes may indeed be warranted. However, there is a real concern when policy changes are hurriedly implemented without the required input from the medical, scientific, or policy research communities. Regardless of how well intentioned, such initiatives are bound to magnify the potential for unintended adverse consequences in the form of far ranging health and social costs. To minimize this risk, science must be front and center in this important policy debate. Here, we review the state of the science on cannabis and cannabinoid health effects, both adverse and therapeutic. We focus on the prevalence of use in different populations, the mechanisms by which
Naftali, Timna; Mechulam, Raphael; Lev, Lihi Bar; Konikoff, Fred M
The marijuana plant Cannabis sativa has been used for centuries as a treatment for a variety of ailments. It contains over 60 different cannabinoid compounds. Studies have revealed that the endocannabinoid system is involved in almost all major immune events. Cannabinoids may, therefore, be beneficial in inflammatory disorders. In murine colitis, cannabinoids decrease histologic and microscopic inflammation. In humans, cannabis has been used to treat a plethora of gastrointestinal problems, including anorexia, emesis, abdominal pain, diarrhea, and diabetic gastroparesis. Despite anecdotal reports on medical cannabis in inflammatory bowel disease (IBD), there are few controlled studies. In an observational study in 30 patients with Crohn's disease (CD), we found that medical cannabis was associated with improvement in disease activity and reduction in the use of other medications. In a more recent placebo-controlled study in 21 chronic CD patients, we showed a decrease in the CD activity index >100 in 10 of 11 subjects on cannabis compared to 4 of 10 on placebo. Complete remission was achieved in 5 of 11 subjects in the cannabis group and 1 of 10 in the placebo group. Yet, in an additional study, low-dose cannabidiol did not have an effect on CD activity. In summary, evidence is gathering that manipulating the endocannabinoid system can have beneficial effects in IBD, but further research is required to declare cannabinoids a medicine. We need to establish the specific cannabinoids, as well as appropriate medical conditions, optimal dose, and mode of administration, to maximize the beneficial effects while avoiding any potential harmful effects of cannabinoid use.
Bunge, Eduardo L; Barilá, Carina V; Sánchez, Natalia A; Maglio, Ana L
Client Satisfaction with mental health services is an important aspect in the evaluation of quality of those services. In youth mental health field, a few studies had being made about this characteristic. The aim of this study is to evaluate the relationship between satisfaction of parents, children and adolescents according to sex of patients and therapists. The sample included 382 subjects who attended to Buenos Aires private services who completed the questionnaire of experiences with the service. The results in teenagers' group showed differences in the satisfaction with the service matching the sex of teenagers with the sex of therapist, however in children and parent groups we haven't found significant differences. We discuss the implications of the results in order to improve the services given in youth area.
Le Foll, Bernard; Trigo, Jose M; Sharkey, Keith A; Le Strat, Yann
Obesity is one of the highest preventable causes of morbidity and mortality in the developed world . It has been well known for a long time that exposure to cannabis produces an increase of appetite (a phenomenon referred to as the 'munchies'). This phenomenon led to an exploration of the role of the endocannabinoid system in the regulation of obesity and associated metabolic syndrome. This effort subsequently led to the development of a successful therapeutic approach for obesity that consisted of blocking the cannabinoid CB1 receptors using ligands such as Rimonabant in order to produce weight loss and improve metabolic profile . Despite being efficacious, Rimonabant was associated with increased rates of depression and anxiety and therefore removed from the market. We recently discovered that the prevalence of obesity is paradoxically much lower in cannabis users as compared to non-users and that this difference is not accounted for by tobacco smoking status and is still present after adjusting for variables such as sex and age. Here, we propose that this effect is directly related to exposure to the Δ(9)-tetrahydrocannabinol (THC) present in cannabis smoke. We therefore propose the seemingly paradoxical hypothesis that THC or a THC/cannabidiol combination drug may produce weight loss and may be a useful therapeutic for the treatment of obesity and its complications.
Woods, Jennifer L.; Shew, Marcia L.; Tu, Wanzhu; Ofner, Susan; Ott, Mary A.; Fortenberry, J. Dennis
Purpose Imperfect oral contraceptive pill (OCP) regimen adherence may impair contraceptive effectiveness. The purpose of this study was to describe daily adherence patterns of OCP use, to analyze OCP protection on an event level basis, and to examine pill-taking and condom use during method transitions. Methods Women (n = 123, ages 14–17 years) completed quarterly interviews to classify OCP method choice into four categories: stable, initiated, stopped, and discordant use. Within each OCP category, daily diaries were used to assess occurrence of coitus, condom use, and patterns of day-to-day OCP use (i.e., consecutive days of OCP use reported with no more than two consecutive days of nonuse). A coital event was OCP protected if pills were used on both the day of the coitus and the day preceding. Results There were 123 participants who reported at least some OCP use in 210 diary periods (average diary length = 75.5 days). Fifty-three participants categorized as stable users reported 87 diary periods: the average interval of consecutive OCP use in this group was 32.5 days. Among stable users, only 45% of coital events were associated with both OCP and condom use. Over one-fifth of coital events in all groups were protected by no method of contraception. Conclusion Dual use of OCP and barrier contraception remains an elusive goal. The time during OCP adoption or discontinuation is often unprotected by condoms. However, concurrent missed pills and condom nonuse increase pregnancy and infection risk even among stable OCP users. Understanding motivation for method usage may improve education and prevention techniques. PMID:16919800
González-Pinto, Ana; González-Ortega, Itxaso; Alberich, Susana; Ruiz de Azúa, Sonia; Bernardo, Miguel; Bioque, Miquel; Cabrera, Bibiana; Corripio, Iluminada; Arango, Celso; Lobo, Antonio; Sánchez-Torres, Ana M.; Cuesta, Manuel J.
The objective of this study is to investigate cognitive performance in a first-episode psychosis sample, when stratifying the interaction by cannabis use and familial or non-familial psychosis. Hierarchical-regression models were used to analyse this association in a sample of 268 first-episode psychosis patients and 237 controls. We found that cannabis use was associated with worse working memory, regardless of family history. However, cannabis use was clearly associated with worse cognitive performance in patients with no family history of psychosis, in cognitive domains including verbal memory, executive function and global cognitive index, whereas cannabis users with a family history of psychosis performed better in these domains. The main finding of the study is that there is an interaction between cannabis use and a family history of psychosis in the areas of verbal memory, executive function and global cognition: that is, cannabis use is associated with a better performance in patients with a family history of psychosis and a worse performance in those with no family history of psychosis. In order to confirm this hypothesis, future research should explore the actual expression of the endocannabinoid system in patients with and without a family history of psychosis. PMID:27513670
González-Pinto, Ana; González-Ortega, Itxaso; Alberich, Susana; Ruiz de Azúa, Sonia; Bernardo, Miguel; Bioque, Miquel; Cabrera, Bibiana; Corripio, Iluminada; Arango, Celso; Lobo, Antonio; Sánchez-Torres, Ana M; Cuesta, Manuel J
The objective of this study is to investigate cognitive performance in a first-episode psychosis sample, when stratifying the interaction by cannabis use and familial or non-familial psychosis. Hierarchical-regression models were used to analyse this association in a sample of 268 first-episode psychosis patients and 237 controls. We found that cannabis use was associated with worse working memory, regardless of family history. However, cannabis use was clearly associated with worse cognitive performance in patients with no family history of psychosis, in cognitive domains including verbal memory, executive function and global cognitive index, whereas cannabis users with a family history of psychosis performed better in these domains. The main finding of the study is that there is an interaction between cannabis use and a family history of psychosis in the areas of verbal memory, executive function and global cognition: that is, cannabis use is associated with a better performance in patients with a family history of psychosis and a worse performance in those with no family history of psychosis. In order to confirm this hypothesis, future research should explore the actual expression of the endocannabinoid system in patients with and without a family history of psychosis.
Beck, F; Legleye, S
Epidemiological monitoring of drug use among adolescents or young adults is a major concern for public policy makers. This surveillance requires the use of adapted methodological solutions. This article presents how far epidemiological surveillance is a useful tool for monitoring drug use at adolescence. It also presents the results of the French general population surveys among adolescents or young adults, and the trends in the last decade. It relies on a survey among 17 years old adolescents and a general population survey among adults (analysis is restricted to people aged 18-25). A European school survey among 16 years old is also presented to compare the French situation to other European countries levels of use. The use of psychoactive substance increases fast with age during adolescence however results vary from one substance to another. Since year 2000, tobacco use is decreasing when alcohol use frequency appears stable between 2003 and 2005, although drunkenness has increased from 2000 to 2005. The frequency of lifetime or occasional use of cannabis appears stable since 2000. Among 17 years old, the proportion of regular users of cannabis has been stable between 2000 and 2005. Finally, the prevalence of ecstasy and cocaine increased during this period of time, despite being less than 4%, but the levels of the other illicit substances are low and stable. The results on alcohol variables and tobacco use in France are rather close to the European average. Four out of five 16 years old students had drunk alcohol during the past 12 months and 36 percent had been drunk during this period (vs 39% in the average European country). About one-third of the students had smoked cigarettes during the past 30 days (close to the 29% in the average European country). The use of cannabis, however, is clearly more prevalent in France. Almost one-third (31%) of the students had already used cannabis (vs 19% in the average European country). The use of inhalants was reported
Lucas, Philippe G
Background In response to a number of court challenges brought forth by Canadian patients who demonstrated that they benefited from the use of medicinal cannabis but remained vulnerable to arrest and persecution as a result of its status as a controlled substance, in 1999 Canada became the second nation in the world to initiate a centralized medicinal cannabis program. Over its six years of existence, this controversial program has been found unconstitutional by a number of courts, and has faced criticism from the medical establishment, law enforcement, as well as the patient/participants themselves. Methods This critical policy analysis is an evidence-based review of court decisions, government records, relevant studies and Access to Information Act data related to the three main facets of Health Canada's medicinal cannabis policy – the Marihuana Medical Access Division (MMAD); the Canadians Institute of Health Research Medical Marijuana Research Program; and the federal cannabis production and distribution program. This analysis also examines Canada's network of unregulated community-based dispensaries. Results There is a growing body of evidence that Health Canada's program is not meeting the needs of the nation's medical cannabis patient community and that the policies of the Marihuana Medical Access Division may be significantly limiting the potential individual and public health benefits achievable though the therapeutic use of cannabis. Canada's community-based dispensaries supply medical cannabis to a far greater number of patients than the MMAD, but their work is currently unregulated by any level of government, leaving these organizations and their clients vulnerable to arrest and prosecution. Conclusion Any future success will depend on the government's ability to better assess and address the needs and legitimate concerns of end-users of this program, to promote and fund an expanded clinical research agenda, and to work in cooperation with community
Adedeji, Olasore H; Akinniyi, Osuntoki A; Abiola, Magbagbeola O; Abayomi, Ojo M
TaqI A polymorphism (rs1800497) has been linked to many substance use disorders but there is a shortage of data on cannabis use disorder. Nigeria has a huge burden of cannabis use disorder, prompting our investigation of the relation between cannabis use disorder and the TaqI A polymorphism among males in Lagos, Nigeria. We recruited 106 males with cannabis use disorder based on International Classification of Diseases, version 10 (ICD-10) and 98 cannabis-naive males for the study. Cannabis use disorder was assessed using the Severity of Dependence Scale (SDS) and Cannabis Use Disorder Identification Test (CUDIT). Genotyping was done using the Restriction Fragment Length Polymorphism (RFLP). The frequency of the A1 allele was higher among the cannabis users (57.8%) compared with the nonusers (42.2%). The genotype distribution was found to be in Hardy-Weinberg equilibrium in both populations. The homozygous A1 genotype alone contributed 11.8% to the variance in the SDS scores. However, both A1/A1 and A1/A2 genotypes contributed to the variance in the CUDIT scores (10.2% and 5.1%, respectively). In conclusion, the distribution of the A1 allele among the general population in this study correlates with the previously reported findings in a southwestern Nigerian population. We also found that carrying an A1 allele appears to be a significant predictor of cannabis use disorder. The result suggests that carrying just a single allele of the A1 is enough to predict cannabis abuse, as shown by the allele association with CUDIT scores. However, double A1 alleles seem to be necessary for the prediction of dependence.
Soueif, M I
To summarize, 12 objective tests that generated 16 test variables were administered to 850 male regular cannabis users and 839 nonusers. The tests were designed to assess various modalities, including speed of psychomotor performance, distance estimation, time estimation, immediate memory, and visuomotor coordination. Most of the test variables differentiated significantly between consumers and controls. At the same time, a significant second-order interaction emerged in most cases. This interaction meant that, under certain conditions that relate to the two dimensions "literacy-illiteracy" and/or "urbanism-ruralism," the superiority of controls over cannabis users became impressive, whereas under other conditions it almost disappeared. To account for this complex pattern of results, a working hypothesis was presented to the effect that "other conditions being equal, the lower the nondrug level of proficiency on tests of cognitive and psychomotor performance the smaller the size of function deficit associated with drug usage." For an empirical examination of the hypothesis, six predictions were formulated. Three predictions defined specific relationships between level of performance, on one hand, and each of three organismic variables, on the other: literacy, urbanism, and age. The remaining predictions delineated relationships to be expected between size of function deficit and the three organismic variables. All our predictions were confirmed, showing less function impairment to be contingent with cannabis usage among the illiterates, rurals, and older subjects. Level of cortical arousal was suggested as the central process associated with the three organismic variables. Because the version of our working hypothesis was formulated with reference to chronic material, the possibility of a transposition of the paradign to research on the acute effects of the drug was discussed. The suggestion was made that our working hypothesis, in either version, is capable of
Cassidy, Clifford M.; Brodeur, Mathieu B.; Lepage, Martin; Malla, Ashok
Background Dysfunctional reward processing is present in individuals with schizophrenia-spectrum disorders (SSD) and may confer vulnerability to addiction. Our objective was to identify a deficit in patients with SSD on response to rewarding stimuli and determine whether this deficit predicts cannabis use. Methods We divided a group of patients with SSD and nonpsychotic controls into cannabis users and nonusers. Response to emotional and cannabis-associated visual stimuli was assessed using self-report, event-related potentials (using the late positive potential [LPP]), facial electromyography and skin-conductance response. Results Our sample comprised 35 patients with SSD and 35 nonpsychotic controls. Compared with controls, the patients with SSD showed blunted LPP response to pleasant stimuli (p = 0.003). Across measures, cannabis-using controls showed greater response to pleasant stimuli than to cannabis stimuli whereas cannabis-using patients showed little bias toward pleasant stimuli. Reduced LPP response to pleasant stimuli was predictive of more frequent subsequent cannabis use (β = −0.24, p = 0.034). Limitations It is not clear if the deficit associated with cannabis use is specific to rewarding stimuli or nonspecific to any kind of emotionally salient stimuli. Conclusion The LPP captures a reward-processing deficit in patients with SSD and shows potential as a biomarker for identifying patients at risk of heavy cannabis use. PMID:24913137
Ko, Gordon D; Bober, Sara L; Mindra, Sean; Moreau, Jason M
Cannabis has been widely used as a medicinal agent in Eastern medicine with earliest evidence in ancient Chinese practice dating back to 2700 BC. Over time, the use of medical cannabis has been increasingly adopted by Western medicine and is thus a rapidly emerging field that all pain physicians need to be aware of. Several randomized controlled trials have shown a significant and dose-dependent relationship between neuropathic pain relief and tetrahydrocannabinol - the principal psychoactive component of cannabis. Despite this, barriers exist to use from both the patient perspective (cost, addiction, social stigma, lack of understanding regarding safe administration) and the physician perspective (credibility, criminality, clinical evidence, patient addiction, and policy from the governing medical colleges). This review addresses these barriers and draws attention to key concerns in the Canadian medical system, providing updated treatment approaches to help clinicians work with their patients in achieving adequate pain control, reduced narcotic medication use, and enhanced quality of life. This review also includes case studies demonstrating the use of medical marijuana by patients with neuropathic low-back pain, neuropathic pain in fibromyalgia, and neuropathic pain in multiple sclerosis. While significant preclinical data have demonstrated the potential therapeutic benefits of cannabis for treating pain in osteoarthritis, rheumatoid arthritis, fibromyalgia, and cancer, further studies are needed with randomized controlled trials and larger study populations to identify the specific strains and concentrations that will work best with selected cohorts.
Maickel, Roger P.
A detailed discussion of marihuana (Cannabis sativa) providing the modes of use, history, chemistry, and physiologic properties of the drug. Cites research results relating to the pharmacologic effects of marihuana. These effects are categorized into five areas: behavioral, cardiovascular-respiratory, central nervous system, toxicity-toxicology,…
Nieri, Tanya; Yabiku, Scott; Stromwall, Layne K.; Marsiglia, Flavio Francisco
Efforts to address youth substance use have focused on prevention among non-users and treatment among severe users with less attention given to youth occupying the middle ground who have used substances but not yet progressed to serious abuse or addiction. Using a sample from 35 middle schools of 1,364 youth who reported using substances, this study examined the effectiveness of a universal youth substance use prevention program, the SAMHSA Model Program keepin’ it REAL, in promoting reduced or recently discontinued alcohol, cigarette, and marijuana use. Discrete-time event history methods modeled the rates of reduced and recently discontinued use across four waves of data. Each substance (alcohol, cigarettes, and marijuana) was modeled separately. Beginning at the second wave, participants who reported use at wave 1 were considered at risk of reducing or discontinuing use. Since the data sampled students in schools, multi-level models accounted for the nesting of data at the school level. Results indicated that prevention program participation influenced the rates of reduced and recently discontinued use only for alcohol, controlling for baseline use severity, age, grades, socioeconomic status, ethnicity and gender. Among youth who reported use of alcohol in wave 1 (N= 1,028), the rate of reducing use for program participants was 72% higher than the rate for control students. The rate of discontinuing use was 66% higher than the rate for control students. Among youth who reported use of one or more of the three substances in wave 1 (N = 1,364), the rate of discontinuing all use was 61% higher for program participants than for control students. Limitations and implications of these findings and plans for further research are discussed. PMID:17096196
Hancox, Robert J; Shin, Hayden H; Gray, Andrew R; Poulton, Richie; Sears, Malcolm R
Smoking cannabis is associated with symptoms of bronchitis. Little is known about the persistence of symptoms after stopping cannabis use. We assessed associations between changes in cannabis use and respiratory symptoms in a population-based cohort of 1037 young adults. Participants were asked about cannabis and tobacco use at ages 18, 21, 26, 32 and 38 years. Symptoms of morning cough, sputum production, wheeze, dyspnoea on exertion and asthma diagnoses were ascertained at the same ages. Frequent cannabis use was defined as ≥52 occasions over the previous year. Associations between frequent cannabis use and respiratory symptoms were analysed using generalised estimating equations with adjustments for tobacco smoking, asthma, sex and age. Frequent cannabis use was associated with morning cough (OR 1.97, p<0.001), sputum production (OR 2.31, p<0.001) and wheeze (OR 1.55, p<0.001). Reducing or quitting cannabis use was associated with reductions in the prevalence of cough, sputum and wheeze to levels similar to nonusers.Frequent cannabis use is associated with symptoms of bronchitis in young adults. Reducing cannabis use often leads to a resolution of these symptoms.
Melis, Miriam; Frau, Roberto; Kalivas, Peter W; Spencer, Sade; Chioma, Vivian; Zamberletti, Erica; Rubino, Tiziana; Parolaro, Daniela
Cannabis sativa preparations are the most consumed illicit drugs for recreational purposes worldwide, and the number of people seeking treatment for cannabis use disorder has dramatically increased in the last decades. Due to the recent decriminalization or legalization of cannabis use in the Western Countries, we may predict that the number of people suffering from cannabis use disorder will increase. Despite the increasing number of cannabis studies over the past two decades, we have gaps of scientific knowledge pertaining to the neurobiological consequences of long-term cannabis use. Moreover, no specific treatments for cannabis use disorders are currently available. In this review, we explore new research that may help fill these gaps. We discuss and provide a solution to the experimental limitation of a lack of rodent models of THC self-administration, and the importance this model can play in understanding the neurobiology of relapse and in providing a biological rationale for potential therapeutic targets. We also focus our attention on glial cells, commenting on recent preclinical evidence suggesting that alterations in microglia and astrocytes might contribute to the detrimental effects associated with cannabis abuse. Finally, due to the worrisome prevalence rates of cannabis use during pregnancy, we highlight the associations between cannabis use disorders during pregnancy and congenital disorders, describing the possible neuronal basis of vulnerability at molecular and circuit level.
... Use and Social Anxiety Study Parses Comorbidity of Cannabis Use and Social Anxiety Email Facebook Twitter October ... difficulties and other cannabis-related problems. SAD and Cannabis Use Severity Further analysis suggested that people with ...
Bolognini, Monique; Plancherel, Bernard; Laget, Jacques; Halfon, Olivier
Adolescence corresponds to a transition period that requires adaptation and change capacities and skills. Most young people succeed with this challenge, whereas a minority fail. In order to identify with the teenage culture, become autonomous, and differentiate from their parents, some adolescents choose to use drugs, beginning with the use of cigarettes, alcohol, cannabis, followed by other illicit drugs such as opiates and stimulants. A high proportion of these adolescents attempt suicide, which is the primary cause of death during adolescence in many European countries. Who are the "vulnerable" adolescents? What are the mechanisms that can explain the varieties of drug-use initiation or suicide attempts? Can "protective factors" be identified? What kind of strategies might be developed at a social and political level in order to prevent or to minimize drug abuse and suicide attempts, among other harmful behaviors? These issues will be discussed on the basis of the recent literature and in the light of a recent study carried out in the French-speaking part of Switzerland on large cohorts of adolescent drug users. Unresolved critical issues are noted and future needed research is suggested.
Miovský, Michal; Voňková, Hana; Gabrhelík, Roman; Šťastná, Lenka
This study aims to examine the effect of school-based preventive intervention on cannabis use in Czech adolescents with different levels of risk factors and provide evidence of its universality. A randomized controlled prevention trial with six waves was conducted over a period of 33 months. We used a two-level logistic random-intercept model for panel data; we first looked at the statistical significance of the effect of the intervention on cannabis use, controlling for the characteristics of the children and time dummies. Then we analyzed the effects of the interactions between the intervention and the characteristics of the children on cannabis use and related it to the definition of universal preventive interventions. The setting for the study was in basic schools in the Czech Republic in the years 2007-2010. A total of 1,874 sixth-graders (mean age 11.82 years) who completed the baseline testing. According to our results, the prevention intervention was effective. We found all the selected characteristics of the children to be relevant in relation to cannabis use, except their relationships with their friends. We showed empirically that the intervention is universal in two dimensions for the selected characteristics of the children. First, all adolescents who undergo the intervention are expected to benefit. Second, with respect to the effect of the intervention on cannabis use, the total level of individual risk of cannabis use is superior to the composition of the risk factors in the individual risk profile. We present indicative evidence that the drug prevention intervention may be considered a true universal preventive intervention.
Cone, Edward J.; Bigelow, George E.; Herrmann, Evan S.; Mitchell, John M.; LoDico, Charles; Flegel, Ronald; Vandrey, Ryan
The increasing use of highly potent strains of cannabis prompted this new evaluation of human toxicology and subjective effects following passive exposure to cannabis smoke. The study was designed to produce extreme cannabis smoke exposure conditions tolerable to drug-free nonsmokers. Six experienced cannabis users smoked cannabis cigarettes [5.3% Δ9-tetrahydrocannabinol (THC) in Session 1 and 11.3% THC in Sessions 2 and 3] in a closed chamber. Six nonsmokers were seated alternately with smokers during exposure sessions of 1 h duration. Sessions 1 and 2 were conducted with no ventilation and ventilation was employed in Session 3. Oral fluid, whole blood and subjective effect measures were obtained before and at multiple time points after each session. Oral fluid was analyzed by ELISA (4 ng/mL cutoff concentration) and by LC–MS-MS (limit of quantitation) for THC (1 ng/mL) and total THCCOOH (0.02 ng/mL). Blood was analyzed by LC–MS-MS (0.5 ng/mL) for THC, 11-OH-THC and free THCCOOH. Positive tests for THC in oral fluid and blood were obtained for nonsmokers up to 3 h following exposure. Ratings of subjective effects correlated with the degree of exposure. Subjective effect measures and amounts of THC absorbed by nonsmokers (relative to smokers) indicated that extreme secondhand cannabis smoke exposure mimicked, though to a lesser extent, active cannabis smoking. PMID:26139312
Imam, A; Ajao, M S; Akinola, O B; Ajibola, M I; Ibrahim, A; Amin, A; Abdulmajeed, W I; Lawal, Z A; Ali-Oluwafuyi, A
The most abused illicit drug in both the developing and the developed world is Cannabis disposing users to varying forms of personality disorders. However, the effects of cannabis on cortico-hippocampal architecture and cognitive behaviours still remain elusive. The present study investigated the neuro-cognitive implications of oral cannabis use in rats. Eighteen adult Wistar rats were randomly grouped to three. Saline was administered to the control rats, cannabis (20 mg/kg) to the experimental group I, while Scopolamine (1 mg/kg. ip) was administered to the last group as a standard measure for the cannabis induced cognitive impairment. All treatments lasted for seven consecutive days. Open Field Test (OFT) was used to assess locomotor activities, Elevated Plus Maze (EPM) for anxiety-like behaviour, and Y maze paradigm for spatial memory and data subjected to ANOVA and T test respectively. Thereafter, rats were sacrificed and brains removed for histopathological studies. Cannabis significantly reduced rearing frequencies in the OFT and EPM, and increased freezing period in the OFT. It also reduced percentage alternation similar to scopolamine in the Y maze, and these effects were coupled with alterations in the cortico-hippocampal neuronal architectures. These results point to the detrimental impacts of cannabis on cortico-hippocampal neuronal architecture and morphology, and consequently cognitive deficits.
Colizzi, Marco; Fazio, Leonardo; Ferranti, Laura; Porcelli, Annamaria; Masellis, Rita; Marvulli, Daniela; Bonvino, Aurora; Ursini, Gianluca; Blasi, Giuseppe; Bertolino, Alessandro
Cannabinoid signaling is involved in different brain functions and it is mediated by the cannabinoid receptor 1 (CNR1), which is encoded by the CNR1 gene. Previous evidence suggests an association between cognition and cannabis use. The logical interaction between genetically determined cannabinoid signaling and cannabis use has not been determined. Therefore, we investigated whether CNR1 variation predicts CNR1 prefrontal mRNA expression in postmortem prefrontal human tissue. Then, we studied whether functional variation in CNR1 and cannabis exposure interact in modulating prefrontal function and related behavior during working memory processing. Thus, 208 healthy subjects (113 males) were genotyped for the relevant functional SNP and were evaluated for cannabis use by the Cannabis Experience Questionnaire. All individuals performed the 2-back working memory task during functional magnetic resonance imaging. CNR1 rs1406977 was associated with prefrontal mRNA and individuals carrying a G allele had reduced CNR1 prefrontal mRNA levels compared with AA subjects. Moreover, functional connectivity MRI demonstrated that G carriers who were also cannabis users had greater functional connectivity in the left ventrolateral prefrontal cortex and reduced working memory behavioral accuracy during the 2-back task compared with the other groups. Overall, our results indicate that the deleterious effects of cannabis use are more evident on a specific genetic background related to its receptor expression. PMID:25139064
Twyman, Laura; Bonevski, Billie; Paul, Christine; Kay-Lambkin, Frances J; Bryant, Jamie; Oldmeadow, C; Palazzi, K; Guillaumier, A
This study aimed to (i) describe concurrent and simultaneous tobacco and cannabis use and (ii) investigate the association between cannabis use and motivation and intentions to quit tobacco in a sample of socioeconomically disadvantaged smokers. A cross-sectional survey was conducted in 2013 and 2014 with current tobacco smokers receiving aid from two community service organizations in New South Wales, Australia. At least weekly cannabis use for the month prior to survey, motivation to quit tobacco and intentions to quit tobacco were measured in 369 participants (77% consent rate). Regressions were carried out to investigate associations between weekly cannabis use and motivation and intentions to quit tobacco.Concurrent tobacco and cannabis use was reported by 19% (n = 71) of the sample and of these users, 100% reported simultaneous use. Although regular cannabis use was significantly associated with lower motivation to quit tobacco, it was not significantly associated with intentions to quit tobacco in the next 30 days. Concurrent cannabis use is common in disadvantaged smokers and may play a role in decreased motivation to quit tobacco; however, it does not appear to be associated with intentions to quit in a sample of disadvantaged smokers.
Jutras-Aswad, Didier; DiNieri, Jennifer A; Harkany, Tibor; Hurd, Yasmin L
Despite the high prevalence of marijuana use among pregnant women and adolescents, the impact of cannabis on the developing brain is still not well understood. However, growing evidence supports that the endocannabinoid system plays a major role in CNS patterning in structures relevant for mood, cognition, and reward, such as the mesocorticolimbic system. It is thus clear that exposure to cannabis during early ontogeny is not benign and potential compensatory mechanisms that might be expected to occur during neurodevelopment appear insufficient to eliminate vulnerability to neuropsychiatric disorders in certain individuals. Both human longitudinal cohort studies and animal models strongly emphasize the long-term influence of prenatal cannabinoid exposure on behavior and mental health. This review provides an overview of the endocannabinoid system and examines the neurobiological consequences of cannabis exposure in pregnancy and early life by addressing its impact on the development of neurotransmitters systems relevant to neuropsychiatric disorders and its association with these disorders later in life. It posits that studying in utero cannabis exposure in association with genetic mutations of neural systems that have strong relationships to endocannabinoid function, such as the dopamine, opioid, glutamate, and GABA, might help to identify individuals at risk. Such data could add to existing knowledge to guide public health platform in regard to the use of cannabis and its derivatives during pregnancy.
Filbey, Francesca M; McQueeny, Tim; DeWitt, Samuel J; Mishra, Virendra
Background As the most commonly used illicit substance during early adolescence, long-term or latent effects of early adolescent marijuana use across adolescent developmental processes remain to be determined. Methods We examined cortical thickness, gray/white matter border contrast (GWR) and local gyrification index (LGI) in 42 marijuana (MJ) users. Voxelwise regressions assessed early-onset (age <16) vs. late-onset (≥16 years-old) differences and relationships to continued use while controlling for current age and alcohol use. Results Although groups did not differ by onset status, groups diverged in their correlations between cannabis use and cortical architecture. Among early-onset users, continued years of MJ use and current MJ consumption were associated with thicker cortex, increased GWR and decreased LGI. Late-onset users exhibited the opposite pattern. This divergence was observed in all three morphological measures in the anterior dorsolateral frontal cortex (p<.05, FWE-corrected). Conclusions Divergent patterns between current MJ use and elements of cortical architecture were associated with early MJ use onset. Considering brain development in early adolescence, findings are consistent with disruptions in pruning. However, divergence with continued use for many years thereafter suggests altered trajectories of brain maturation during late adolescence and beyond. PMID:26507433
Gorter, Robert W; Butorac, Mario; Cobian, Eloy Pulido; van der Sluis, Willem
The authors investigated the indications for cannabis prescription in the Netherlands and assessed its efficacy and side effects. A majority (64.1%) of patients reported a good or excellent effect on their symptoms. Of these patients, approximately 44% used cannabis for >/=5 months. Indications were neurologic disorders, pain, musculoskeletal disorders, and cancer anorexia/cachexia. Inhaled cannabis was perceived as more effective than oral administration. Reported side effects were generally mild.
This paper describes Robin Room's contribution to cannabis policy debates over the period 1993-2010. It focuses on a controversy that erupted over a review that Room and the author undertook for the World Health Organization in the mid-1990s on the comparative harms of cannabis, alcohol, opiates and tobacco. It also briefly describes Room's recent work on global cannabis policy and ends with a brief appreciation of the character of his scholarly contributions to this field.
Tian, Y.; Zhang, F.; Jia, K.; Wen, M.; Yuan, Ch.
Cannabis is an economically important plant that is used in many fields, in addition to being the most commonly consumed illicit drug worldwide. Monitoring the spatial distribution of cannabis cultivation and judging whether it is drug- or fiber-type cannabis is critical for governments and international communities to understand the scale of the illegal drug trade. The aim of this study was to investigate whether the cannabinoids content in cannabis could be spectrally quantified using a spectrometer and to identify the optimal wavebands for quantifying the cannabinoid content. Spectral reflectance data of dried cannabis leaf samples and the cannabis canopy were measured in the laboratory and in the field, respectively. Correlation analysis and the stepwise multivariate regression method were used to select the optimal wavebands for cannabinoid content quantification based on the laboratory-measured spectral data. The results indicated that the delta-9-tetrahydrocannabinol (THC) content in cannabis leaves could be quantified using laboratory-measured spectral reflectance data and that the 695 nm band is the optimal band for THC content quantification. This study provides prerequisite information for designing spectral equipment to enable immediate quantification of THC content in cannabis and to discriminate drug- from fiber-type cannabis based on THC content quantification in the field.
Alexander, Stephen P H
In this review, I will consider the dual nature of Cannabis and cannabinoids. The duality arises from the potential and actuality of cannabinoids in the laboratory and clinic and the 'abuse' of Cannabis outside the clinic. The therapeutic areas currently best associated with exploitation of Cannabis-related medicines include pain, epilepsy, feeding disorders, multiple sclerosis and glaucoma. As with every other medicinal drug of course, the 'trick' will be to maximise the benefit and minimise the cost. After millennia of proximity and exploitation of the Cannabis plant, we are still playing catch up with an understanding of its potential influence for medicinal benefit.
Webb, Charles W; Webb, Sandra M
Clinical research regarding the therapeutic benefits of cannabis ("marijuana") has been almost non-existent in the United States since cannabis was given Schedule I status in the Controlled Substances Act of 1970. In order to discover the benefits and adverse effects perceived by medical cannabis patients, especially with regards to chronic pain, we hand-delivered surveys to one hundred consecutive patients who were returning for yearly re-certification for medical cannabis use in Hawai'i. The response rate was 94%. Mean and median ages were 49.3 and 51 years respectively. Ninety-seven per cent of respondents used cannabis primarily for chronic pain. Average pain improvement on a 0-10 pain scale was 5.0 (from 7.8 to 2.8), which translates to a 64% relative decrease in average pain. Half of all respondents also noted relief from stress/anxiety, and nearly half (45%) reported relief from insomnia. Most patients (71%) reported no adverse effects, while 6% reported a cough or throat irritation and 5% feared arrest even though medical cannabis is legal in Hawai'i. No serious adverse effects were reported. These results suggest that Cannabis is an extremely safe and effective medication for many chronic pain patients. Cannabis appears to alleviate pain, insomnia, and may be helpful in relieving anxiety. Cannabis has shown extreme promise in the treatment of numerous medical problems and deserves to be released from the current Schedule I federal prohibition against research and prescription.
Benyamina, Amine; Reynaud, Michel
The therapeutic use of cannabis has generated a lot of interest in the past years, leading to a better understanding of its mechanisms of action. Countries like the United States and Canada have modified their laws in order to make cannabinoid use legal in the medical context. It's also the case in France now, where a recent decree was issued, authorizing the prescription of medication containing "therapeutic cannabis" (decree no. 2013-473, June 5, 2013). Cannabinoids such as dronabinol, Sativex and nabilone have been tested for the treatment of acute and chronic pain. These agents are most promising to relieve chronic pain associated with cancer, with human immunodeficiency virus infection and with multiple sclerosis. However, longer-term studies are required to determine potential long-term adverse effects and risks of misuse and addiction.
Haller, Sven; Curtis, Logos; Badan, Maryse; Bessero, Séverine; Albom, Mara; Chantraine, Fabrice; Alimenti, Alessandro; Lovblad, Karl-Olof; Giannakopoulos, Panteleimon; Merlo, Marco
Cannabis consumption is temporally associated with the development of first episode psychosis (FEP). Whether or not the chronic use of this substance induces structural brain changes that may be responsible for the cognitive and psychological disturbances in this disorder is still matter of debate. To address this issue, we compared the magnetic resonance imaging (MRI)-assessed grey (GM) and white matter (WM) changes in young FEP patients between users versus non-users of cannabis. This prospective study included 50 consecutive FEP subjects: 33 users (22.7 ± 4.1 years, 4 women) and 17 non-users (23.9 ± 4.2 years, 10 women). Users were further divided into 15 heavy (23.3 ± 4.5 years, 2 women) and 18 light users (22.2 ± 3.8 years, 2 women) according to their lifetime cannabis use. Voxel-based-morphometry (VBM) analysis of GM and tract-based-spatial-statistics (TBSS) analysis of WM were performed. Age and gender were used as non-explanatory co-regressors. There were no supra-threshold differences between user and non-user groups for both GM and WM parameters. This was also the case when only heavy users were compared to non-users. Multivariate models controlling for age and gender confirmed these findings. We found no evidence for cannabis consumption related alterations in GM or WM in FEP subjects. Due to the strict correction for multiple comparisons and sample size, we cannot formally exclude subtle morphometric changes associated with cannabis