Cannabis use and dependence among Australian adults: results from the National Survey of Mental Health and Wellbeing

Cannabis use and cannabis use disorders and their treatment in the Europe

This paper introduces the special issue on cannabis use in Europe. It describes data on the prevalence of cannabis use in Europe and the more limited data on the prevalence of cannabis use disorders, one of the most common forms of drug problem treated in many countries in Europe. It summarises what research has indicated about the adverse effects of acute and chronic cannabis use and discusses potential health system responses that may reduce some of these harms. These include public education about the risks of cannabis use; screening and brief interventions in primary medical settings; and specialist treatment for cannabis use disorders. It briefly indicates the special issues that may need to be addressed in dealing with the high rates of comorbidity between cannabis use disorders, other types of drug use disorders, and common mental disorders.

Vaping preferences of individuals who vaporise dry herb cannabis, cannabis liquids and cannabis concentrates

In 2019 an estimated 200 million people aged 15-64 used cannabis, making cannabis the most prevalent illicit substance worldwide. The last decade has seen a significant expansion in the cannabis vaporiser market, introducing cannabis vaporisation as a common administration method alongside smoking and ingestion. Despite reports of increased prevalence of cannabis vaporisation there has been little research into the use of these devices. To remedy the current dearth of data in this area this study utilised an anonymous online survey of individuals who self-reported past cannabis vaporisation. The respondents (N = 557) were predominantly young (<35 years) and male. Most (91.4 %) stated they had ever vaped dry herb cannabis, 59.1 % reported vaporisation of cannabis oil or liquids, and 34.0 % reported vaporisation of cannabis concentrates. This study identifies the types of vaporisation devices (including brands and models) employed by cannabis vapers, as well as the vaporisation temperatures and puff durations commonly used for dry herb, cannabis liquids and cannabis concentrates. To the best of our knowledge, this is the first time the usual operating temperatures of these vaporisation devices and user specific consumption patterns such as puff duration have been reported for cannabis vaping. This information will allow for a more realistic understanding of patterns of recreational use and improve experimental conditions in research settings to reflect the user's context.

Cannabis use among patients with cutaneous lymphoma: A cross-sectional survey

OBJECTIVE

To evaluate patterns of cannabis use in patients with cutaneous lymphoma (CL), as well as the association between cannabis use and itch specifically.

DESIGN

Cross-sectional survey created in partnership with the Cutaneous Lymphoma Foundation (CLF).

SETTING

The online survey was distributed electronically via email to the CLF listserv and links posted to social media over a 2-week period. Main Outcome Measures Respondents were classified as current cannabis users, prior users, and never users. A visual analog scale (VAS) was used to assess itching severity, improvement of itch, and interest in learning about cannabis.

RESULTS

A total of 119 patient responses (61% female, mean age 59y) were included in analysis. The majority had mycosis fungoides or Sézary syndrome (74%; 88/119) and early stage (IA-IIA) disease (56%; 48/86). Mean VAS itch score was 3.2 + 2.8 for the cohort. Over half (55%; 60/110) reported ever having used cannabis, with 22% (24/110) endorsing current cannabis use. Common methods of cannabis use were smoking (54%) and vaporizing (46%). 25% (6/24) of current users reported using cannabis specifically to treat itch; these respondents noted that cannabis resulted in moderate improvement of itching (mean 6.6/10). There was strong interest in learning more about cannabis and cancer, and most desired this information from their CL doctor/nurse.

CONCLUSIONS

Cannabis use is common among patients with CL, and patients report improvement of itching as a result of using cannabis. Further studies are needed to elucidate the risks and benefits of cannabis use in this patient population.

Driving After Cannabis Use Among Young Adults in Michigan

Introduction: Driving after cannabis use is associated with a number of risks. Examination of driving after cannabis use among young adults is particularly important, as young adults have the highest rates of cannabis use and among the highest rates of traffic crashes. The current study examines rates and correlates of driving after cannabis use among young adults (aged 18-25) who reported past month cannabis use. Methods: Participants were from Michigan and recruited through paid Facebook and Instagram advertisements between February and March 2018 (n=461). Results: Nearly a third (31.9%) of the sample reported driving after cannabis use in the past month. Young adults who were employed (aOR=1.872, p=0.045), had medical cannabis cards (aOR=2.877, p<0.001), endorsed coping reasons for use (aOR=2.992, p=0.007), and endorsed social/recreational reasons for use (aOR=1.861, p=0.034) had greater odds of driving after cannabis use. Students had lower odds of driving after use (aOR=0.573, p=0.011). Conclusions: Employment and having a medical cannabis card may be important risk markers for identifying individuals more likely to drive after use of cannabis. Prevention efforts could provide psychoeducation at dispensaries to individuals with medical cannabis cards about the risks of driving after use. Coping motives for cannabis use may also be useful in identifying young adults at the greatest risk of driving after use of cannabis.

A systematic review and meta-analysis of sex differences in cannabis use disorder amongst people with comorbid mental illness

BACKGROUND

While males are more likely diagnosed with cannabis use disorder (CUD), females are more susceptible to developing and maintaining CUD. Yet, for both sexes, CUD is associated with high rates of comorbid mental illness (MI).

OBJECTIVES

To identify and compare sex differences in the prevalence of comorbid CUD amongst individuals with/without MIs.

METHODS

This systematic review generated pooled odds ratios (OR) and 95% confidence intervals (CI) from 37 studies (including clinical trials, cohort, and case-control studies) among individuals with and without MIs, quantifying sex differences in rates of comorbid CUD. A meta-analysis was also completed.

RESULTS

In the CUD-only group, males were twice as likely to have CUD than females (OR = 2.0, CI = 1.9-2.1). Among MIs, males were more likely than females to have CUD comorbid with schizophrenia (OR ~2.6, CI = 2.5-2.7) and other psychotic, mood, and substance use disorders (1> OR <2.2, CI = 0.7-2.6). The reverse association (females > males) was observed for anxiety disorders and antisocial personality disorder (OR = 0.8, CI = 0.7-1.0). Among females, MIs increased the likelihood of having CUD, except for psychotic disorders and depression. A meta-analysis was inconclusive due to high heterogeneity across studies. Thus, comparisons across MI groups were not possible.

CONCLUSION

While males are more likely to be diagnosed with CUD, there are important sex differences in the prevalence of CUD across MI diagnoses that should be taken into account when approaching CUD prevention and determining treatment efficacy.

Public perception of medicinal and recreational cannabis and its effect on mental health: a survey of a regional Australian town

OBJECTIVE

To investigate beliefs about treatment capabilities of medicinal cannabis (MC), the effect of recreational cannabis (RC) on mental health and online cannabis search trends.

METHOD

Participants (n = 117) completed an online survey, and search engine optimisation software was used to analyse internet search trends.

RESULTS

Half the participants perceived RC as harmful to mental health but were uncertain if it impairs treatment for depression or prevents anxiety. Participants believed MC can treat depression and/or anxiety. The Google keyword 'CBD oil' is most popular when seeking cannabis information and provides misinformation.

CONCLUSION

Australians are exposed to misinformation about MC online, explaining why participants believed that MC could treat anxiety and/or depression and why there is a reduction in the belief that RC is harmful to mental health. Health authorities should incorporate search engine optimisation strategies to provide accurate information about cannabis.

Is the Urine Cannabinoid Level Measured via a Commercial Point-of-Care Semiquantitative Immunoassay a Cannabis Withdrawal Syndrome Severity Predictor?

Background: For cannabis-dependent subjects, the relationship between cannabis withdrawal syndrome (CWS) severity and the urine cannabinoid concentrations are unclear; we investigated this using a commercial point-of-care (POC) enzyme immunoassay detecting 11-nor-9-carboxy-Delta-9-tetrahydrocannabinol (THC-COOH). Methods: Observational study of 78 adult chronic cannabis-dependent subjects assessed over a 24-day inpatient detoxification treatment, with 13 serial measurement days. Repeated Measures Correlation and Multilevel Linear Models were employed. Results: Absolute urinary THC-COOH levels significantly correlated with Marijuana Withdrawal Checklist (MWC) scores across the entire study duration (r = 0.248; p < 0.001). Correlation between serial creatinine-adjusted THC-COOH ratios and serial MWC scores emerged as significant only in the sample with higher MWC scores (>11 points) at admission (n = 21; r = 0.247; p = 0.002). The aforementioned significant relationships have persisted when replacing the absolute THC-COOH-levels with the (relative) day-to-day change in urinary THC-COOH levels. MWC scores were significantly correlated with the Clinical Global Impression-Severity (CGI-S; r = 0.812; p < 0.001). Females showed a significantly slower decline in urine THC-COOH levels and prolonged CWS course characterized by substantial illness severity (per CGI-S), occurring in nearly 30% of cases. Conclusion: Urine cannabinoid levels (THC-COOH) determined by POC assay significantly predicted CWS severity (moderate correlation), guiding detoxification treatment duration. In patients with MWC > 11 points upon admission, creatinine-adjusted THC-COOH ratios also significantly predicted CWS severity-again with moderate effect size. Females showed prolonged urinary THC-COOH elimination and cannabis withdrawal.

Can a Smartphone App for Cannabis Cessation Gain a Broader User Group than Traditional Treatment Services?

Background:

Treatment demand for cannabis use disorders is increasing in Europe. Mobile phone– and internet-based interventions for cannabis users can possibly help meet the need. The purpose of this study was to examine whether a recently developed Norwegian Cannabis Cessation app reaches a broader or different user group compared to community-based Cannabis Cessation programs (CCP, Nordic abbreviation: HAP).

Method:

The app respondents (n = 148) were recruited through an online link in the app. A comparative sample (n = 102) was recruited in three municipally based CCPs in Norway. We examined whether app users differed from the CCP population in sociodemographics, substance use, mental health, and well-being.

Result:

The app group included more women than the CCP group (46% versus 26%, χ² = 10.9, P = .001), but otherwise the groups were similar for sociodemographic variables. Severity of cannabis use did not differ between groups, but the app sample exhibited a higher depressiveness score on the Hopkins Symptom Checklist (mean difference, 0.24; 95% CI 0.04–0.44; P = .018) and lower perceived well-being (3.4 point lower score on the Outcome Rating Scale; 95% CI −5.7 to −1.2; P = .003). Well-being was negatively associated with being in the app group, being older, and having higher levels of mental distress, and was positively associated with the perceived ability to make changes (‘self-efficacy of quitting’).

Conclusion:

The higher proportion of women in the app group indicated that the app did capture an expanded segment of the cannabis-using population. The app can be an alternative for those who are not yet prepared to seek treatment in formal healthcare services. The high level of depressive symptoms and lower levels of well-being among the app respondents suggest that some app users might need additional support.

The Cannabis Abuse Screening Test (CAST) revisited: examining measurement invariance by age

Defensible use of self-reported cannabis use problem scales in age comparative frameworks requires that measured constructs have equal psychometric properties across age groups. This study compares the psychometric properties of the Cannabis Abuse Screening Test (CAST) across three age groups (18-24, 25-29, 30-40). Data was collected online from an accessible sample of 1316 cannabis users. Factor analysis compared the optimal factor structure and dimensionality diffraction. Multi-group Model Invariance tests examined measurement invariance across the three age groups. CAST was two-dimensional in all age groups with one factor measuring cannabis use problems and the other measuring deviation from a common standard of use. The two-dimensional structure was more pronounced in older age groups. Weak factorial invariance was supported, suggesting that the meaning of the CAST factors is equivalent across age groups. Partial, but not full, strong factorial invariance was supported, indicating that only the cannabis use problem factor can be defensibly used to measure age group mean differences. Results confirm a well-defined two-dimensional CAST structure and factorial invariance across age groups. However, caution is needed when using the two items measuring deviation from a common standard in an age-comparative framework. Replication studies based on a representative sample are needed.

Depression and anxiety among chronic pain patients receiving prescription opioids and medical marijuana

BACKGROUND

High rates of depression and anxiety have been consistently reported among patients suffering from chronic pain. Prescription opioids are one of the most common modalities for pharmacological treatment of pain, however in recent years medical marijuana(MM) has been increasingly used for pain control in the US and in several countries worldwide. The aim of this study was to compare levels of depression and anxiety among pain patients receiving prescription opioids and MM.

METHODS

Participants were patients suffering from chronic pain treated with prescription opioids (OP,N=474), MM (N=329) or both (OPMM,N=77). Depression and anxiety were assessed using the depression module of the Patient Health Questionnaire (PHQ-9) and the Generalized Anxiety Disorder scale (GAD-7).

RESULTS

Prevalence of depression among patients in the OP, MM and OPMM groups was 57.1%, 22.3% and 51.4%, respectively and rates of anxiety were 48.4%, 21.5% and 38.7%, respectively. After controlling for confounders, patients in the OP group were significantly more likely to screen positive for depression (Adjusted Odds Ratio(AOR)=6.18;95%CI=4.12-9.338) and anxiety(AOR=4.12;CI=3.84-5.71)) compared to those in the MM group. Individuals in the OPMM group were more prone for depression (AOR for depression=3.34;CI=1.52-7.34)) compared to those in the MM group.

LIMITATIONS

Cross-sectional study, restricting inference of causality.

CONCLUSIONS

Levels of depression and anxiety are higher among chronic pain patients receiving prescription opioids compared to those receiving MM. Findings should be taken into consideration when deciding on the most appropriate treatment modality for chronic pain, particularly among those at risk for depression and anxiety.

Prohibition and Cannabis Use in Australia: A Survey of 18- to 29-year-olds

The prevalence of cannabis use in Australia has increased in the last few years, prompting some to argue that the prohibition against cannabis is both costly and ineffective and should be lifted. Surveys designed to evaluate the effect of reducing or eliminating sanctions for cannabis use, however, have been more concerned about the effect of cannabis law reform on the number of new cannabis users than about its effect on cannabis consumption among existing users. This is a serious oversight because most of the risks associated with cannabis are associated with regular rather than occasional use of the drug. The present research was designed to assess some of the potential effects of lifting the prohibition against cannabis use.The study results suggest that, while the illegal status of cannabis does act to limit its use, it is not a major factor in decisions about whether to use cannabis or to cease using it. Prohibition does, however, appear to limit consumption among existing cannabis users and particularly among those who use the drug on a weekly basis or more frequently.

Marijuana: Views on Its Medical Use Recorded at the Slovak Social Network

We describe opinions on medical use of Cannabis sativa L under conditions of Slovakia (n = 717). Personal experience with marijuana was detected in 77.42% (n = 553) in age categories younger than 20 years (n = 96) and in 77.06% (n = 457) of adults. Almost 86% of respondents (n = 618) agreed with legal use of marijuana for medical purposes. Furthermore, respondents' views on legal usage of marijuana for medical purposes could be affected by availability of information (r = .12) and personal experience (r = .23). Negative impact of substance abuse in younger age-groups was recognized as threat (r = .47), but knowledge about harmful effect of marijuana use did not affect personal opinion for decriminalization (r = .38).

Psychological and psychosocial interventions for cannabis cessation in adults: a systematic review short report

BACKGROUND

Cannabis is the most commonly used illicit drug worldwide. Cannabis dependence is a recognised psychiatric diagnosis, often diagnosed via the Diagnostic and Statistical Manual of Mental Disorders criteria and the International Classification of Diseases, 10th Revision. Cannabis use is associated with an increased risk of medical and psychological problems. This systematic review evaluates the use of a wide variety of psychological and psychosocial interventions, such as motivational interviewing (MI), cognitive-behavioural therapy (CBT) and contingency management.

OBJECTIVE

To systematically review the clinical effectiveness of psychological and psychosocial interventions for cannabis cessation in adults who use cannabis regularly.

DATA SOURCES

Studies were identified via searches of 11 databases [MEDLINE, EMBASE, Cochrane Controlled Trials Register, Health Technology Assessment (HTA) database, Database of Abstracts of Reviews of Effects, Cochrane Database of Systematic Reviews, NHS Economic Evaluation Database, PsycINFO, Web of Science Conference Proceedings Citation Index, ClinicalTrials.gov and metaRegister of Current Controlled Trials] from inception to February 2014, searching of existing reviews and reference tracking.

METHODS

Randomised controlled trials (RCTs) assessing psychological or psychosocial interventions in a community setting were eligible. Risk of bias was assessed using adapted Cochrane criteria and narrative synthesis was undertaken. Outcomes included change in cannabis use, severity of cannabis dependence, motivation to change and intervention adherence.

RESULTS

The review included 33 RCTs conducted in various countries (mostly the USA and Australia). General population studies: 26 studies assessed the general population of cannabis users. Across six studies, CBT (4-14 sessions) significantly improved outcomes (cannabis use, severity of dependence, cannabis problems) compared with wait list post treatment, maintained at 9 months in the one study with later follow-up. Studies of briefer MI or motivational enhancement therapy (MET) (one or two sessions) gave mixed results, with some improvements over wait list, while some comparisons were not significant. Four studies comparing CBT (6-14 sessions) with MI/MET (1-4 sessions) also gave mixed results: longer courses of CBT provided some improvements over MI. In one small study, supportive-expressive dynamic psychotherapy (16 sessions) gave significant improvements over one-session MI. Courses of other types of therapy (social support group, case management) gave similar improvements to CBT based on limited data. Limited data indicated that telephone- or internet-based interventions might be effective. Contingency management (vouchers for abstinence) gave promising results in the short term; however, at later follow-ups, vouchers in combination with CBT gave better results than vouchers or CBT alone. Psychiatric population studies: seven studies assessed psychiatric populations (schizophrenia, psychosis, bipolar disorder or major depression). CBT appeared to have little effect over treatment as usual (TAU) based on four small studies with design limitations (both groups received TAU and patients were referred). Other studies reported no significant difference between types of 10-session therapy.

LIMITATIONS

Included studies were heterogeneous, covering a wide range of interventions, comparators, populations and outcomes. The majority were considered at high risk of bias. Effect sizes were reported in different formats across studies and outcomes.

CONCLUSIONS

Based on the available evidence, courses of CBT and (to a lesser extent) one or two sessions of MI improved outcomes in a self-selected population of cannabis users. There was some evidence that contingency management enhanced long-term outcomes in combination with CBT. Results of CBT for cannabis cessation in psychiatric populations were less promising, but may have been affected by provision of TAU in both groups and the referred populations. Future research should focus on the number of CBT/MI sessions required and potential clinical effectiveness and cost-effectiveness of shorter interventions. CBT plus contingency management and mutual aid therapies warrant further study. Studies should consider potential effects of recruitment methods and include inactive control groups and long-term follow-up. TAU arms in psychiatric population studies should aim not to confound the study intervention.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42014008952.

FUNDING

The National Institute for Health Research HTA programme.

Natural outcome of cannabis use disorder: a 3-year longitudinal follow-up

AIMS

To assess the prevalence and correlates of remission from cannabis use disorders (CUDs), focusing on the proportion of individuals with CUDs that remit without abstaining from cannabis use.

DESIGN

Three-year longitudinal study.

SETTING

Wave 1 (2001) and wave 2 (2004) of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a nationally representative sample of US adults aged 18 years and over.

PARTICIPANTS

Our sample included 444 individuals diagnosed with DSM-IV cannabis abuse and/or dependence during the 12 months prior to wave 1 of the NESARC.

MEASUREMENTS

Baseline socio-demographic and clinical correlates were analysed for possible outcomes of CUDs after 3 years: abstinent remission, non-abstinent remission and sustained disorder.

FINDINGS

Approximately two-thirds (67%) of individuals with baseline CUD remitted at follow-up. Approximately 37% of those who remitted were non-abstinent. Remission was associated with Hispanic ethnicity [odds ratio (OR)=2.59; 95% confidence interval (CI)=1.27-4.87], baseline daily or almost daily use of cannabis (OR=1.91; 95% CI=1.15-3.16), baseline use of other drugs (OR=1.63; 95% CI=1.04-2.56) and two or more medical conditions at baseline (OR=8.40; 95% CI=2.67-26.41). Non-abstinent remission was associated with baseline daily or almost daily use of cannabis (OR=1.92; 95% CI=1.05-3.51).

CONCLUSIONS

A substantial level of remission from cannabis use disorders (CUDs), including non-abstinent remission, suggests that the nature of CUDs may be more unstable than reported previously.

Factors associated with the timing and onset of cannabis use and cannabis use disorder: results from the 2007 Australian National Survey of Mental Health and Well-Being

INTRODUCTION AND AIMS

To investigate the predictors of both initiation of cannabis use and transition to cannabis use disorder (CUD) in a nationally representative sample using discrete-time survival analyses.

DESIGN AND METHODS

Data from a nationally representative sample of 6935 Australian adults. Retrospective data on age of first cannabis use and onset of CUD were used to construct pseudo-longitudinal datasets and survival models used to evaluate factors associated with age of first use and time from first use to onset of CUD.

RESULTS

The oldest cohort (born 1942-1951) had lower cannabis use than younger cohorts, with first use also occurring at an older age. Multivariable discrete-time survival models showed other substance use, tobacco and alcohol use at very young ages, and mental disorders were associated with increased risk of cannabis use. There were 7.5% of those <65 years old at interview who had a lifetime CUD; mean time from first use to the onset of CUD was 3.3 years, with 90% of cases within eight years. Younger age of initiation and other substance use were strong predictors of the transition from use to CUD. Women with depression were more likely to develop a CUD; social phobia and panic disorder were also associated with transition from cannabis use to CUD.

DISCUSSION AND CONCLUSIONS

Patterns of cannabis use differ across birth cohorts. There are multiple factors associated with use and transition to CUD, with other substance use a strong predictor. Mental disorders also predict initiation and progression to CUD.

Motivational and control mechanisms underlying adolescent cannabis use disorders: A prospective study

•

Adolescents with a CUD had an attentional but no approach bias towards cannabis.

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Cannabis craving significantly predicted cannabis use 6 months later.

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These findings identify craving as a predictor of treatment outcome.

•

This study is among the first to investigate neuropsychological mechanisms underlying adolescent CUDs.

Cannabis use disorders (CUDs) are the most prevalent substance use disorders among adolescents in treatment. Yet, little is known about the neuropsychological mechanisms underlying adolescent CUDs. Studies in adult cannabis users suggest a significant role for cognitive control and cannabis-oriented motivational processes, such as attentional bias, approach bias, and craving in CUDs. The current 6-month prospective study investigated the relationships between attentional bias, approach bias, craving, cognitive control, and cannabis use in adolescent patients in treatment for a primary or secondary CUD. Moreover, we investigated if these motivational processes and cognitive control could predict treatment progression after 6 months. Adolescents with a CUD had an attentional but no approach bias towards cannabis. In contrast to adult findings on the role of attentional bias, approach bias and cognitive control, only cannabis craving significantly correlated with current cannabis use and predicted cannabis use-related problems and abstinence from cannabis 6 months later. These findings identify craving as a predictor of treatment outcome, thereby supporting an important role for craving in the course of adolescent cannabis use and dependence. This prospective study is among the first to investigate neuropsychological mechanisms underlying adolescent CUDs, warranting future longitudinal studies.

Predicting the transition from frequent cannabis use to cannabis dependence: a three-year prospective study

BACKGROUND

Frequent cannabis users are at high risk of dependence, still most (near) daily users are not dependent. It is unknown why some frequent users develop dependence, whereas others do not. This study aims to identify predictors of first-incidence DSM-IV cannabis dependence in frequent cannabis users.

METHODS

A prospective cohort of frequent cannabis users (aged 18-30, n=600) with baseline and two follow-up assessments (18 and 36 months) was used. Only participants without lifetime diagnosis of DSM-IV cannabis dependence at baseline (n=269) were selected. Incidence of DSM-IV cannabis dependence was established using the Composite International Diagnostic Interview version 3.0. Variables assessed as potential predictors of the development of cannabis dependence included sociodemographic factors, cannabis use variables (e.g., motives, consumption habits, cannabis exposure), vulnerability factors (e.g., childhood adversity, family history of mental disorders or substance use problems, personality, mental disorders), and stress factors (e.g., life events, social support).

RESULTS

Three-year cumulative incidence of cannabis dependence was 37.2% (95% CI=30.7-43.8%). Independent predictors of the first incidence of cannabis dependence included: living alone, coping motives for cannabis use, number and type of recent negative life events (major financial problems), and number and type of cannabis use disorder symptoms (impaired control over use). Cannabis exposure variables and stable vulnerability factors did not independently predict first incidence of cannabis dependence.

CONCLUSIONS

In a high risk population of young adult frequent cannabis users, current problems are more important predictors of first incidence cannabis dependence than the level and type of cannabis exposure and stable vulnerability factors.

Mental health differences between frequent cannabis users with and without dependence and the general population

AIMS

To compare the prevalence of mental disorders between frequent cannabis users with and without dependence and the general population.

DESIGN

Cross-sectional comparison of interview data.

SETTING

Enriched community sample of frequent cannabis users and a representative sample of non-users and non-frequent users from the general population.

PARTICIPANTS

A total of 521 young adult (aged 18-30 years) frequent cannabis users, 252 of whom were with DSM-IV cannabis dependence (D+) and 269 without DSM-IV cannabis dependence (D-), and 1072 young adults from the general population.

MEASUREMENTS

Multinomial logistic regression was used to compare groups regarding the presence of DSM-IV mental disorders. Detailed measures of cannabis use, childhood adversity and other substance use were considered confounders.

FINDINGS

Compared with the general population, externalizing disorders were more prevalent in D- [odds ratio (OR) = 8.91, P < 0.001] and most prevalent in D+ (OR = 17.75, P < 0.001), but internalizing disorders were associated only with D+ (mood OR = 4.15, P < 0.001; anxiety OR = 2.20, P = 0.002). Associations were attenuated (and often became non-significant) after correction for childhood adversity and substance use other than cannabis. However, the prevalence of mental disorders remained higher in D+ compared with D- (OR = 2.40, P < 0.001), although cannabis use patterns were remarkably similar.

CONCLUSIONS

Cannabis use patterns, childhood adversity and the use of other substances are similar in dependent and non-dependent frequent cannabis users. With the exception of more externalizing disorders, the mental health condition of non-dependent frequent cannabis users is similar to that of the general population, whereas it is worse in dependent frequent cannabis users.

Prevalence, correlates and comorbidity of DSM-IV Cannabis Use and Cannabis Use Disorders in Australia

OBJECTIVE

To report nationally representative findings on the prevalence, correlates, psychiatric comorbidity and treatment of DSM-IV Cannabis Use and Cannabis Use Disorders in Australia.

METHOD

The 2007 National Survey of Mental Health and Wellbeing was a nationally representative household survey of 8841 Australians (16-85 years) that assessed symptoms of the most prevalent DSM-IV mental disorders.

RESULTS

Prevalence of lifetime and 12-month cannabis use was 18% and 6%; prevalence of lifetime and 12-month cannabis use disorder was 6% and 1%. The conditional prevalence (proportion of ever users who met criteria for a disorder) of lifetime and 12-month cannabis use disorder was 32.2% and 14.3%. Current cannabis use disorders were more common in males (OR 2.0) and younger users (OR 4.6). Strong associations were observed between current cannabis use disorders and alcohol use disorders (OR 3.6) and current affective disorders (OR 3.0). Only 36.2% of those with current cannabis use disorders sought any treatment.

CONCLUSIONS

The prevalence of cannabis use disorders in the Australian population is comparable with that in the USA. Current cannabis use disorders are highly concentrated in young Australians who have high levels of comorbidity. The low rates of treatment seeking warrant attention in treatment and prevention strategies.

Diagnostic criteria for cannabis withdrawal syndrome

OBJECTIVE

Cannabis withdrawal occurs in frequent users who quit, but there are no accepted diagnostic criteria for a cannabis withdrawal syndrome (CWS). This study evaluated diagnostic criteria for CWS proposed in DSM-V and two earlier proposals.

METHOD

A convenience sample of 384 adult, non-treatment-seeking lifetime cannabis smokers provided retrospective self-report data on their "most difficult" quit attempt without formal treatment, which was used in this secondary analysis. Prevalence, time of onset, and peak intensity (5-point Likert scale) for 39 withdrawal symptoms (drawn from the literature) were assessed via computer-administered questionnaire. Subject groups were compared using chi-square or ANOVA. Symptom clustering was evaluated with principal components analysis.

RESULTS

40.9% of subjects met the DSM-V criterion of ≥3 symptoms from a list of 7. There were no associations with sex, race, or type of cannabis preparation used. There were significant positive associations between duration or frequency of cannabis use prior to the quit attempt and experiencing CWS. Subjects with CWS had a significantly shorter duration of abstinence. Alternative syndromal criteria (dropping physical symptoms from DSM-V list; requiring ≥2 or ≥4 symptoms from a list of 11) yielded a similar prevalence of CWS and similar associations with prior cannabis use and relapse. The PCA yielded 12 factors, including some symptom clusters not included in DSM-V.

CONCLUSIONS

Findings support the concurrent and predictive validity of the proposed DSM-V CWS, but suggest that the list of withdrawal symptoms and number required for diagnosis warrant further evaluation.

The Cannabis Withdrawal Scale development: patterns and predictors of cannabis withdrawal and distress

BACKGROUND

Rates of treatment seeking for cannabis are increasing, and relapse is common. Management of cannabis withdrawal is an important intervention point. No psychometrically sound measure for cannabis withdrawal exists, and as a result treatment developments cannot be optimally targeted. The aim is to develop and test the psychometrics of the Cannabis Withdrawal Scale and use it to explore predictors of cannabis withdrawal.

METHODS

A volunteer sample of 49 dependent cannabis users provided daily scores on the Cannabis Withdrawal Scale during a baseline week and 2 weeks of abstinence.

RESULTS

Internal reliability (Cronbach's alpha=0.91), test-retest stability (average intra-class correlation=0.95) and content validity analysis show that the Cannabis Withdrawal Scale has excellent psychometric properties. Nightmares and/or strange dreams was the most valid item (Wald χ²=105.6, P<0.0001), but caused relatively little associated distress (Wald χ²=25.11, P=0.03). Angry outbursts were considered intense (Wald χ²=73.69, P<0.0001) and caused much associated distress (Wald χ²=45.54, P<0.0001). Trouble getting to sleep was also an intense withdrawal symptom (Wald χ²=42.31, P<0.0001) and caused significant associated distress (Wald χ²=47.76, P<0.0001). Scores on the Severity of Dependence Scale predicted cannabis withdrawal.

CONCLUSIONS

The Cannabis Withdrawal Scale can be used as a diagnostic instrument in clinical and research settings where regular monitoring of withdrawal symptoms is required.

A postal intervention for dependent cannabis users

INTRODUCTION AND AIMS. In Australia, many would-be treatment seekers for problematic cannabis use live in rural and remote areas, thereby limiting their access to face-to-face treatments. In order to address this gap in treatment availability, the present study aimed to assess the feasibility of a mail-based intervention for regular cannabis users.

DESIGN AND METHODS

Treatment was based upon cognitive-behavioural and motivational interviewing principles, and consisted of six treatment modules posted fortnightly to participants. In addition to the standardised modules, participants received personalised feedback at four points, based upon their mailed-in responses to the modules. Participants were recruited via advertisements in rural newspapers and a Google advertisement.

RESULTS

A total of 268 people expressed interest in this study and 36 participants went on to complete treatment. Treatment completers demonstrated a significant reduction in cannabis use at the 1 month follow-up.

DISCUSSION AND CONCLUSIONS

Transposing face-to-face treatments into a mailed format has shown some promise and future research is warranted to determine the efficacy of such treatments in a controlled study.

Barriers and facilitators to cannabis treatment

INTRODUCTION AND AIMS. Despite its continued widespread use, relatively few individuals with cannabis use disorders present to treatment services. There is a dearth of research examining the reasons for this observed underutilisation of treatment. The aim of this paper is to examine barriers and facilitators to entry into cannabis treatment.

DESIGN AND METHODS

Three surveys of regular cannabis users in treatment (n=100), in the community (n=100) and from a widespread Internet sample (n=294).

RESULTS

Perceived barriers included: not being aware of treatment options; thinking treatment is unnecessary; not wanting to stop using cannabis; and wanting to avoid the stigma associated with accessing treatment. Perceived facilitators included: improving available information on treatment; keeping treatment specific to cannabis; offering additional services, such as telephone support; and simplifying treatment admission processes.

DISCUSSION AND CONCLUSIONS

Participant's perceptions differed significantly depending on their age, gender and treatment status. Participants in treatment typically reported barriers intrinsic to the individual while participants from the community reported barriers relating to the treatment available. Reported facilitators were more homogenous and most commonly related to availability of information.

Cannabis withdrawal symptoms in non-treatment-seeking adult cannabis smokers

BACKGROUND

Cannabis withdrawal is not recognized in DSM-IV because of doubts about its clinical significance.

OBJECTIVES

Assess the phenomenon of cannabis withdrawal and its relationship to relapse in non-treatment-seeking adults.

SUBJECTS

Convenience sample of 469 adult cannabis smokers who had made a quit attempt while not in a controlled environment.

METHODS

Subjects completed a 176-item Marijuana Quit Questionnaire collecting information on sociodemographic characteristics, cannabis use history, and their "most difficult" cannabis quit attempt.

RESULTS

42.4% of subjects had experienced a lifetime withdrawal syndrome, of whom 70.4% reported using cannabis in response to withdrawal. During the index quit attempt, 95.5% of subjects reported > or =1 individual withdrawal symptom (mean [SD] 9.5 [6.1], median 9.0); 43.1% reported > or =10. Number of withdrawal symptoms was significantly associated with greater frequency and amount of cannabis use, but symptoms occurred even in those using less than weekly. Symptoms were usually of > or = moderate intensity and often prompted actions to relieve them. Alcohol (41.5%) and tobacco (48.2%) were used more often than cannabis (33.3%) for this purpose. There was little change during withdrawal in use of other legal or illegal substances.

CONCLUSIONS

Cannabis withdrawal is a common syndrome among adults not seeking treatment. The intention to relieve withdrawal symptoms can drive relapse during quit attempts, giving cannabis withdrawal clinical significance as a target of treatment.

Initial response to cigarettes predicts rate of progression to regular smoking: findings from an offspring-of-twins design

The aim of this study was to examine the association between initial subjective effects from cigarettes and the rate of progression from first cigarette to regular smoking. Latent class analysis (LCA) was applied to subjective effects data from 573 offspring of twins ranging in age from 14 to 32 years. LCA revealed four classes: 1) High on both pleasurable and physiological responses, 2) Cough only response, 3) High on physiological, low on pleasurable responses, and 4) High on pleasurable, low on physiological responses. Classes of responses were then used to predict time from first cigarette to the onset of regular smoking in a Cox proportional hazards model. Time-varying covariates representing relevant psychiatric and psychosocial factors as well as dummy variables representing the offspring-of-twins design were included in the model. Members of classes 1 and 4 transitioned more rapidly to regular smoking than the classes characterized as low on the pleasurable response dimension. Our findings provide evidence that previously reported associations between pleasurable initial experiences and progression to regular smoking hold true as well for the rate at which that transition occurs. Furthermore, the fact that profiles of responses did not fall into global categories of exclusively pleasurable vs. exclusively negative (physiological) responses suggests the importance of considering both dimensions in combination to characterize risk for smoking-related outcomes.

Do antisocial females exhibit poor outcomes in adulthood? An Australian cohort study

OBJECTIVE

Antisocial behaviour in young people is common and associated with adverse effects in adulthood. The question whether these effects are observed in both genders remains controversial. A typology of antisocial behaviour that captures childhood limited (CL), adolescent onset (AO) and life course persistent behaviour (LCP) through both developmental stages is utilized to examine young adult outcomes in both sexes.

METHODS

The Mater-University of Queensland Study of Pregnancy (MUSP) data set is a longitudinal study following up a cohort of 7223 infants and mothers from antenatal care to the child's 21st year. Data on child antisocial behaviour was collected at ages 5 and 14 years. At the 21-year follow up, self-reported outcomes were collected on antisocial behaviour, use of alcohol, tobacco and cannabis, physical and mental health functioning. The relationship between the three antisocial sub-types and negative young adult outcomes was examined for both males and females using a series of logistic regressions.

RESULTS

Complete data across 21 years was available for 3173 participants. Males experienced higher levels of antisocial behaviour. In both males and females, AO and LCP groups exhibited elevated risk of negative outcomes including continuing antisocial behaviour, cannabis use, general health problems and depression/anxiety symptoms. The CL group exhibited poorer outcomes in physical and mental health but not in other domains.

CONCLUSION

Both males and females exhibiting AO and LCP antisocial behaviour are at increased risk of serious adverse outcomes in young adulthood. The significant loss to follow up of high-risk groups suggests the important relationship between early antisocial behaviour and problems in adulthood have been underestimated. Further research is required to understand antisocial behaviour in adolescence, identify factors that reinforce its continuity into adulthood, and identify interventions which are able to modify adult outcomes.

Role of the cannabinoid system in pain control and therapeutic implications for the management of acute and chronic pain episodes

Cannabis extracts and synthetic cannabinoids are still widely considered illegal substances. Preclinical and clinical studies have suggested that they may result useful to treat diverse diseases, including those related with acute or chronic pain. The discovery of cannabinoid receptors, their endogenous ligands, and the machinery for the synthesis, transport, and degradation of these retrograde messengers, has equipped us with neurochemical tools for novel drug design. Agonist-activated cannabinoid receptors, modulate nociceptive thresholds, inhibit release of pro-inflammatory molecules, and display synergistic effects with other systems that influence analgesia, especially the endogenous opioid system. Cannabinoid receptor agonists have shown therapeutic value against inflammatory and neuropathic pains, conditions that are often refractory to therapy. Although the psychoactive effects of these substances have limited clinical progress to study cannabinoid actions in pain mechanisms, preclinical research is progressing rapidly. For example, CB(1)mediated suppression of mast cell activation responses, CB(2)-mediated indirect stimulation of opioid receptors located in primary afferent pathways, and the discovery of inhibitors for either the transporters or the enzymes degrading endocannabinoids, are recent findings that suggest new therapeutic approaches to avoid central nervous system side effects. In this review, we will examine promising indications of cannabinoid receptor agonists to alleviate acute and chronic pain episodes. Recently, Cannabis sativa extracts, containing known doses of tetrahydrocannabinol and cannabidiol, have granted approval in Canada for the relief of neuropathic pain in multiple sclerosis. Further double-blind placebo-controlled clinical trials are needed to evaluate the potential therapeutic effectiveness of various cannabinoid agonists-based medications for controlling different types of pain.

The epidemiology of cannabis use and cannabis-related harm in Australia 1993-2007

AIMS

To examine trends in patterns of cannabis use and related harm in the Australian population between 1993 and 2007.

DESIGN

Analysis of prospectively collected data from: (1) the National Drug Strategy Household Survey (NDSHS) and Australian Secondary Student Alcohol and Drug Survey (ASSADS); (2) the National Hospital Morbidity Database (NHMD); and (3) the Alcohol and Other Drug Treatment Services National Minimum Dataset (AODTS-NMDS).

PARTICIPANTS

Australians aged 14 years and over from the general population; students aged 12-17 years; public and private hospital in-patients; public and private in-patients and out-patients attending for drug treatment.

MEASUREMENT

Prevalence of 12-month cannabis use among the general population and secondary students. Proportions in the general population by age group reporting: daily cannabis use; difficulties in controlling cannabis use; and heavy cannabis use on each occasion. Number of hospital and treatment presentations for cannabis-related problems.

FINDINGS

Prevalence of past-year cannabis use has declined in the Australian population since the late 1990s. Among those reporting past-year use, daily use is prevalent among 40-49-year-olds, while heavy patterns of use are prevalent among 14-19-year-olds. Hospital presentations for cannabis-related problems reflect similar trends. Past-year cannabis use has decreased among the 10-19-year age group, but those who are daily users in this age group report using large quantities of cannabis.

CONCLUSIONS

Despite declines in the prevalence of cannabis use, continued public health campaigns warning of the harms associated with cannabis use are essential, aimed particularly at users who are already experiencing problems. The increasing demand for treatment for cannabis problems in Australia suggests the need for more accessible and more effective interventions for cannabis use disorders.

"Youthful epidemic" or diagnostic bias? Differential item functioning of DSM-IV cannabis use criteria in an Australian general population survey

BACKGROUND

Prevalence rates of cannabis abuse and dependence are higher for younger adults when compared with older adults. It is necessary to examine the performance of criteria across age groups to establish whether these differences in prevalence rates are a result of diagnostic bias. The current study aims to investigate whether there is any age-related differential item functioning in the DSM-IV diagnostic criteria for cannabis use disorders using an item response theory approach.

METHOD

The sample consisted of 10,641 participants in a population-based survey of Australian adults aged 18 years and older. DSM-IV cannabis use disorders were assessed in all respondents who had used cannabis more than five times in the previous twelve months (n=722). Age-based differential item functioning was assessed in each of the DSM-IV criteria for cannabis use disorders.

RESULTS

Age-based differential item functioning was only detected in the Hazard criterion of the DSM-IV cannabis use disorders. The Hazard criterion was found to be more discriminating for those aged 18-24 when compared with those aged 25 and over.

CONCLUSIONS

The DSM-IV criteria for cannabis use disorders appear to function similarly across age groups. Differential item functioning was only detected in the alpha parameter for the Hazard criterion. These results are discussed with regard to implications for future editions of the DSM system.

Linkage analyses of cannabis dependence, craving, and withdrawal in the San Francisco family study

Cannabis is the most widely used illicit drug in the United States. There is ample evidence that cannabis use has a heritable component, yet the genes underlying cannabis use disorders are yet to be completely identified. This study's aims were to map susceptibility loci for cannabis use and dependence and two narrower cannabis-related phenotypes of "craving" and "withdrawal" using a family study design. Participants were 2,524 adults participating in the University of California San Francisco (UCSF) Family Alcoholism Study. DSM-IV diagnoses of cannabis dependence, as well as indices of cannabis craving and withdrawal, were obtained using a modified version of the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA). Genotypes were determined for a panel of 791 microsatellite polymorphisms. Multipoint variance component LOD scores were obtained using SOLAR. Genome-wide significance for linkage (LOD > 3.0) was not found for the DSM-IV cannabis dependence diagnosis; however, linkage analyses of cannabis "craving" and the cannabis withdrawal symptom of "nervous, tense, restless, or irritable" revealed five sites with LOD scores over 3.0 on chromosomes 1, 3, 6, 7, and 9. These results identify new regions of the genome associated with cannabis use phenotypes as well as corroborate the importance of several chromosome regions highlighted in previous linkage analyses for other substance dependence phenotypes.

Cannabis dependence in the San Francisco Family Study: age of onset of use, DSM-IV symptoms, withdrawal, and heritability

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 (h(2)=0.31) and dependence (h(2)=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.

Correlates of later-onset cannabis use in the National Epidemiological Survey on Alcohol and Related Conditions (NESARC)

BACKGROUND

Much of the research surrounding correlates of cannabis initiation has focused on adolescent and young adult populations. However, there is growing evidence that cannabis onset occurs later in life as well and little is known of the risk and protective influences that are associated with late-onset cannabis initiation.

METHODS

We used data on 34,653 individuals that participated in both the first wave and the 3-year follow-up (3YFU) of the National Epidemiological Survey on Alcohol and Related Conditions (NESARC). Univariate and multivariate logistic regression was used to examine the association between cannabis initiation at 3YFU and socio-demographic, religious/pro-social and psychiatric measures. Analyses were also conducted in age bands to further distinguish across the lifespan.

RESULTS

Of the 27,467 lifetime abstainers at wave 1509 had initiated cannabis use at 3YFU. Consistent associations between divorce, religious attendance, volunteer/community service, alcohol abuse/dependence, nicotine dependence and cannabis initiation were noted in the full sample and across age-bands.

CONCLUSIONS

Religious and pro-social activities are negatively associated with late-onset cannabis onset while divorce and alcohol and nicotine-related problems are positively associated with later onset.

Heritability and a genome-wide linkage analysis of a Type II/B cluster construct for cannabis dependence in an American Indian community

Subtyping of substance dependence disorders holds promise for a number of important research areas including phenotyping for genetic studies, characterizing clinical course, and matching treatment and prevention strategies. This study sought to investigate whether a dichotomous construct similar to Babor's Types A/B and Cloninger's Types I/II for alcohol dependence can be identified for cannabis dependence in a Native American sample. In addition, heritability of this construct and its behavior in a genetic linkage analyses were evaluated. Information on cannabis use and dependence symptoms and other psychiatric disorders was obtained using the Semi-Structured Assessment for the Genetics of Alcoholism from a community sample of 606 American Indians. Hierarchical average linkage and K means cluster analysis was used, and a three-cluster solution was found to generate the best separation of variables. Ninety-one per cent of cannabis-dependent participants fell into one of the two subtypes: Type A/I cluster (n = 114, 56%) and Type B/II cluster (n = 70, 35%). Heritability (estimated using Sequential Oligogenic Linkage Analysis Routines) was only significant for the Type B/II cluster (h(2) = 0.44, SE = 0.18, P < 0.01). Evidence for linkage was found for the Type B/II cluster (versus no diagnosis) on chromosome 16 [at 139 centimorgans (cM), Log of the Odds (LOD) score = 4.4], and on chromosome 19 (at 74 cM, LOD score = 6.4). Regions of interest for this phenotype (LOD > 1.5) were also located on chromosomes 14, 21, 22. These findings suggest that a Type B/II cannabis dependence phenotype can be identified in this population and that it is in part heritable and linked to areas of the genome identified previously for drug dependence phenotypes in this population as well as in other studies.

The adverse health effects of cannabis use: what are they, and what are their implications for policy?

BACKGROUND

The adverse health effects of cannabis are a source of contention in debates about policies towards the drug.

METHODS

This paper provides a review of epidemiological evidence on the major adverse health effects of cannabis use and considers its implications for policy.

RESULTS

The evidence strongly suggests that cannabis can adversely affect some users, especially adolescents who initiate use early and young adults who become regular users. These adverse effects probably include increased risks of: motor vehicle crashes, the development of cannabis dependence, impaired respiratory function, cardiovascular disease, psychotic symptoms, and adverse outcomes of adolescent development, namely, poorer educational outcomes and an increased likelihood of using other illicit drugs.

CONCLUSIONS

Politically, evidence of adverse health effects favours the status quo in developed countries like Australia where cannabis policy has been framed by the media as a choice between two views: (1) either cannabis use is largely harmless to most users and so we should legalize, or at the very least decriminalize its use; or (2) it harms some of its users so we should continue to prohibit its use.

Cannabis use disorder: epidemiology and management

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.

Marijuana coping motives interact with marijuana use frequency to predict anxious arousal, panic related catastrophic thinking, and worry among current marijuana users

The present investigation evaluated whether coping motives for marijuana use interacted with past 30-day frequency of marijuana use in relation to anxiety-relevant variables among community-recruited young adult marijuana users (n=149). As expected, after covarying cigarettes per day, alcohol use, and total years of marijuana use, the interaction between frequency of past 30-day marijuana use and coping motives predicted anxious arousal symptoms, agoraphobic cognitions, and worry. Marijuana users who demonstrated high use frequency and high coping motives demonstrated the highest levels of anxiety across these anxiety-relevant criterion variables. No such effects were evident, as expected, for depressive symptoms, offering explanatory specificity for anxiety relative to depressive factors. These results are discussed in relation to better understanding the role of marijuana use and coping motives in regard to anxiety vulnerability.

Lithium carbonate in the management of cannabis withdrawal in humans: an open-label study

Cannabis is the most widely used illicit substance in the world. Estimates suggest that approximately 10-20% of cannabis users meet criteria for cannabis dependence and a significant proportion experience withdrawal discomfort on cessation of use. To date, there has been an absence of any clinically validated treatments to manage withdrawal. The current study is an open-label trial exploring the utility of lithium carbonate for the management of cannabis withdrawal symptoms in treatment seeking adult humans. In total, 20 participants were recruited to the study (19 men). All met DSM-IV cannabis-dependence criteria and had been smoking cannabis daily or almost daily for a mean 9 years. Participants were admitted to an inpatient detoxification facility and prescribed lithium 500 mg b.d. for 7 days. Cannabis withdrawal was assessed daily with the Marijuana Withdrawal Checklist (MWC). Two participants were withdrawn from the trial because of possible adverse effects. Sixty percent of participants completed the 7-day treatment program. Follow-up was conducted at a mean of 107 days following treatment. The mean percentage of days abstinent in the period between treatment cessation and follow-up was 87.57%. Twenty-nine percent of participants (n=5) reported continuous abstinence that was biochemically verified at follow-up. Agreement between self-reported cannabis use and urinalysis at follow-up was moderate (kappa=0.47). Significant reductions in symptoms of depression and anxiety and cannabis-related problems were also reported. This study provides evidence for the potential clinical utility and safety of lithium in the management of cannabis withdrawal. A randomised, placebo-controlled trial is recommended.

Sessions, Cyphers, and Parties

The importance of settings for marijuana use has been widely noted, but the way that informal social controls are organized to moderate the amounts consumed have not been well documented. A major ethnographic study of blunts/marijuana use in New York City observed several hundred marijuana users in group locations and conducted intensive interviews with 92 focal subjects. The vast majority of blunt smokers preferred to consume in a group setting. Participants identified three group settings in which blunt smoking often occurred-sessions, cyphers, and parties. The analysis identifies various conduct norms, rituals, and behavior patterns associated with each of these settings. Regardless of the setting, group processes encouraged equal sharing of blunts, moderation in consumption, intermission and breaks between smoking episodes, and involvement in non-smoking activities. Blunt smoking groups rarely encouraged high consumption and intoxication from marijuana.

The developmental antecedents of illicit drug use: evidence from a 25-year longitudinal study

BACKGROUND

The present study examined the developmental antecedents of illicit drug use and abuse/dependence.

METHODS

A 25-year prospective longitudinal study of the health, development, and adjustment of a birth cohort of 1265 New Zealand children. Measures included assessments of adolescent and young adult illicit drug use and abuse/dependence; cannabis use to age 25; measures of parental adjustment; measures of exposure to childhood sexual abuse, physical abuse, and interparental violence; novelty-seeking; childhood and early adolescent adjustment and substance use; and affiliation with substance-using peers.

RESULTS

Illicit drug use and abuse/dependence from ages 16 to 25 were significantly associated (all p values<.05) with a range of parental adjustment measures; exposure to abuse in childhood; individual factors; and measures of childhood and early adolescent adjustment. Analyses using repeated measures logistic regression models suggested that parental illicit drug use, gender, novelty-seeking, and childhood conduct disorder predicted later illicit drug use and abuse/dependence. Further analyses revealed that these pathways to illicit drug use and abuse/dependence were mediated via cannabis use, affiliation with substance-using peers, and alcohol use during ages 16-25.

CONCLUSIONS

The current study suggested that the illicit drug use and abuse/dependence were associated with a range of early life circumstances and processes that put individuals at greater risk of illicit drug use and abuse/dependence. However, the use of cannabis in late adolescence and early adulthood emerged as the strongest risk factor for later involvement in other illicit drugs.