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

A phase III multisite randomised controlled trial to compare the efficacy of cannabidiol to placebo in the treatment of cannabis use disorder: the CBD-CUD study protocol

BACKGROUND

Cannabis use disorder (CUD) is increasingly common and contributes to a range of health and social problems. Cannabidiol (CBD) is a non-intoxicating cannabinoid recognised for its anticonvulsant, anxiolytic and antipsychotic effects with no habit-forming qualities. Results from a Phase IIa randomised clinical trial suggest that treatment with CBD for four weeks reduced non-prescribed cannabis use in people with CUD. This study examines the efficacy, safety and quality of life of longer-term CBD treatment for patients with moderate-to-severe CUD.

METHODS/DESIGN

A phase III multi-site, randomised, double-blinded, placebo controlled parallel design of a 12-week course of CBD to placebo, with follow-up at 24 weeks after enrolment. Two hundred and fifty adults with moderate-to-severe CUD (target 20% Aboriginal), with no significant medical, psychiatric or other substance use disorders from seven drug and alcohol clinics across NSW and VIC, Australia will be enrolled. Participants will be administered a daily dose of either 4 mL (100 mg/mL) of CBD or a placebo dispensed every 3-weeks. All participants will receive four-sessions of Cognitive Behavioural Therapy (CBT) based counselling. Primary endpoints are self-reported cannabis use days and analysis of cannabis metabolites in urine. Secondary endpoints include severity of CUD, withdrawal severity, cravings, quantity of use, motivation to stop and abstinence, medication safety, quality of life, physical/mental health, cognitive functioning, and patient treatment satisfaction. Qualitative research interviews will be conducted with Aboriginal participants to explore their perspectives on treatment.

DISCUSSION

Current psychosocial and behavioural treatments for CUD indicate that over 80% of patients relapse within 1-6 months of treatment. Pharmacological treatments are highly effective with other substance use disorders but there are no approved pharmacological treatments for CUD. CBD is a promising candidate for CUD treatment due to its potential efficacy for this indication and excellent safety profile. The anxiolytic, antipsychotic and neuroprotective effects of CBD may have added benefits by reducing many of the mental health and cognitive impairments reported in people with regular cannabis use.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trial Registry: ACTRN12623000526673 (Registered 19 May 2023).

Mental ill-health and substance use among sexuality diverse adolescents: The critical role of school climate and teacher self-efficacy

INTRODUCTION

Mental ill-health, substance use and their co-occurrence among sexuality diverse young people during earlier adolescence is relatively understudied. The preventive utility of positive school climate for sexuality diverse adolescents' mental health is also unclear, as well as the role of teachers in conferring this benefit.

METHOD

Using Wave 8 'B Cohort' data from the Longitudinal Study of Australian children (N = 3127, Mage = 14.3), prevalence ratios and odds ratios were used to assess prevalence and disparities in mental ill-health and substance use, and multinomial logistic regression for co-occurring outcomes, among sexuality diverse adolescents relative to heterosexual peers. Logistic regression was used to assess associations between school climate and teacher self-efficacy with sexuality diverse adolescents' mental health.

RESULTS

Mental ill-health prevalence ranged from 22% (suicidal thoughts/behaviour) to 46% (probable depressive disorders) and substance use between 66% (cigarette use) and 97% (alcohol use). Sexuality diverse participants were significantly more likely to report self-harm and high levels of emotional symptoms in co-occurrence with cigarette, alcohol and/or cannabis use. For each 1-point increase in school climate scores as measured by the Psychological Sense of School Membership scale, there was 10% reduction in sexuality diverse adolescents reporting high levels of emotional symptoms, probable depressive disorder, self-harm thoughts/behaviour and suicidal thoughts/behaviour. For each 1-point increase in lower perceived (worse) teacher self-efficacy scores as measured by four bespoke teacher self-efficacy items, odds of sexuality diverse adolescent-reported suicidal thoughts/behaviour increased by 80%.

DISCUSSION

Mental ill-health, substance use and especially their co-occurrence, are highly prevalent and pose significant and inequitable health and well-being risks. Schools represent a potential site for focusing future prevention efforts and educating and training teachers on sexuality diversity is a promising pathway towards optimising these.

A randomized controlled trial of brief intervention for patients with cannabis use disorder

Objectives

Effective interventions for cannabis use disorders are fairly limited. The present randomized controlled trial (RCT) aimed to compare the reduction in cannabis use (number of days cannabis used) with brief intervention and simple advice in patients with cannabis use disorder.

Materials and Methods

This non-blinded and parallel two-group RCT included 100 male patients with cannabis use disorder. A semi-structured pro forma and severity of dependence scale (SDS) were used. Participants were then randomized to either of the two arms (brief intervention and simple advice) in a 1:1 ratio. Cannabis use patterns and SDS scores were assessed over the phone at week 4, week 8, and week 12.

Results

The two groups were comparable in sociodemographics and cannabis use characteristics. Participants in both groups were using cannabis for 30 days in the past month before enrolment. The brief intervention group had a lesser number of days of cannabis use vis-a-vis the simple advice group at 4, 8, and 12 weeks. There was a significant time effect for change in SDS scores (F = 30.629, P < 0.001), but the group effect was not significant (F = 0.379, P = 0.541).

Conclusion

In this population of regular cannabis users, brief intervention may be useful in reducing cannabis usage. It can be integrated into routine assessments and management of those with regular use of cannabis.

A Prospective Comparison of Bipolar I and II Subjects with and without Comorbid Cannabis Use Disorders from the COGA Dataset

OBJECTIVE

The comorbidity of alcohol and substance use disorders among persons with bipolar disorder is elevated, as indicated by epidemiological and clinical studies. Following alcohol use, cannabis is the most frequently used and abused illicit substance among bipolar individuals, and such use may lead to comorbid cannabis use disorders (CUD). Previous research indicated that CUDs were related to a more severe course of bipolar disorder and higher rates of other comorbid alcohol and substance use disorders. Few studies, however, have conducted longitudinal research on this comorbidity. The aim of this study is to investigate the influence of CUD on the course of bipolar I and II individuals during a 5-year follow-up.

METHODS

The characteristics of bipolar disorder, cannabis use disorders, and other alcohol and substance use disorders, as well as comorbid mental disorders, were assessed using a standardized semi-structured interview (SSAGA) at both baseline and the 5-year follow-up. N = 180 bipolar I and II patients were subdivided into groups of with and without comorbid cannabis use disorders (CUD).

RESULTS

Of the 77 bipolar I and 103 bipolar II patients, n = 65 (36.1%) had a comorbid diagnosis of any CUD (DSM-IV cannabis abuse or dependence). Comorbid bipolar patients with CUD had higher rates of other substance use disorders and posttraumatic stress disorders, more affective symptoms, and less psychosocial functioning at baseline and at 5-year follow-up. In contrast to previously reported findings, higher rates of anxiety disorders and bipolar disorder complications (e.g., mixed episodes, rapid cycling, and manic or hypomanic episodes) were not found. The effect of CUD on other substance use disorders was confirmed using moderation analyses.

CONCLUSIONS

A 5-year prospective evaluation of bipolar patients with and without CUD confirmed previous investigations, suggesting that the risk of other substance use disorders is significantly increased in comorbid individuals. CUD has a moderation effect, while no effect was found for other mental disorders. Findings from this study and previous research may be due to the examination of different phenotypes (Cannabis use vs. CUD) and sample variation (family study vs. clinical and epidemiological populations).

Risk of readmission among individuals with cannabis use disorder during a 15-year cohort study: the impact of socio-economic factors and psychiatric comorbidity

BACKGROUND AND AIM

Cannabis use disorder (CUD) is one of the main reasons for seeking substance treatment in the Nordic countries, but there are few studies on readmission to care. We aimed to characterize CUD readmission and estimate the magnitude of how socio-economic factors and psychiatric comorbidity influence the risk of CUD readmission.

DESIGN, SETTING AND PARTICIPANTS

This was a nation-wide cohort study carried out between 2001 and 2016 in Sweden. The participants were individuals with CUD, aged 17 years and above (n = 12 143).

MEASUREMENTS

Information on predictors was obtained from registers and included education, income and psychiatric comorbidity assessed by six disease groups. The outcome measure was readmission, defined as a CUD visit to health-care at least 6 months after initial CUD diagnosis. Hazard ratios (HR) were estimated using Cox survival analyses and flexible parametric survival analyses to assess risk of readmission and how the risk varied with age.

FINDINGS

The vast majority of CUD visits took place in outpatient care (~80%). Approximately 23% of the included individuals were readmitted to care during follow-up. The fully adjusted model showed an increased risk of readmission among those with schizophrenia and other psychotic disorders [HR = 1.54, 95% confidence interval (CI) = 1.29-1.84], low education (HR = 1.40, 95% CI = 1.24-1.57), personality disorders (HR = 1.27, 95% CI = 1.05-1.54) or mood disorders (HR = 1.27, 95% CI = 1.12-1.45). Flexible parametric modeling revealed increased risk of readmission mainly in individuals aged 18-35 years.

CONCLUSIONS

The risk of readmission was highest among those with low education, schizophrenia and other psychotic disorders, mood-related disorders or personality disorders. Individuals aged 18-35 years showed the highest risk of readmission. Our findings highlight individuals with complex health-care needs.

Clinical management of cannabis withdrawal

BACKGROUND AND AIMS

Cannabis withdrawal is a well-characterized phenomenon that occurs in approximately half of regular and dependent cannabis users after abrupt cessation or significant reductions in cannabis products that contain Δ⁹ -tetrahydrocannabinol (THC). This review describes the diagnosis, prevalence, course and management of cannabis withdrawal and highlights opportunities for future clinical research.

METHODS

Narrative review of literature.

RESULTS

Symptom onset typically occurs 24-48 hours after cessation and most symptoms generally peak at days 2-6, with some symptoms lasting up to 3 weeks or more in heavy cannabis users. The most common features of cannabis withdrawal are anxiety, irritability, anger or aggression, disturbed sleep/dreaming, depressed mood and loss of appetite. Less common physical symptoms include chills, headaches, physical tension, sweating and stomach pain. Despite limited empirical evidence, supportive counselling and psychoeducation are the first-line approaches in the management of cannabis withdrawal. There are no medications currently approved specifically for medically assisted withdrawal (MAW). Medications have been used to manage short-term symptoms (e.g. anxiety, sleep, nausea). A number of promising pharmacological agents have been examined in controlled trials, but these have been underpowered and positive findings not reliably replicated. Some (e.g. cannabis agonists) are used 'off-label' in clinical practice. Inpatient admission for MAW may be clinically indicated for patients who have significant comorbid mental health disorders and polysubstance use to avoid severe complications.

CONCLUSIONS

The clinical significance of cannabis withdrawal is that its symptoms may precipitate relapse to cannabis use. Complicated withdrawal may occur in people with concurrent mental health and polysubstance use.

Associations between cannabis use, cannabis use disorder, and mood disorders: longitudinal, genetic, and neurocognitive evidence

RATIONALE

Cannabis use among people with mood disorders increased in recent years. While comorbidity between cannabis use, cannabis use disorder (CUD), and mood disorders is high, the underlying mechanisms remain unclear.

OBJECTIVES

We aimed to evaluate (1) the epidemiological evidence for an association between cannabis use, CUD, and mood disorders; (2) prospective longitudinal, genetic, and neurocognitive evidence of underlying mechanisms; and (3) prognosis and treatment options for individuals with CUD and mood disorders.

METHODS

Narrative review of existing literature is identified through PubMed searches, reviews, and meta-analyses. Evidence was reviewed separately for depression, bipolar disorder, and suicide.

RESULTS

Current evidence is limited and mixed but suggestive of a bidirectional relationship between cannabis use, CUD, and the onset of depression. The evidence more consistently points to cannabis use preceding onset of bipolar disorder. Shared neurocognitive mechanisms and underlying genetic and environmental risk factors appear to explain part of the association. However, cannabis use itself may also influence the development of mood disorders, while others may initiate cannabis use to self-medicate symptoms. Comorbid cannabis use and CUD are associated with worse prognosis for depression and bipolar disorder including increased suicidal behaviors. Evidence for targeted treatments is limited.

CONCLUSIONS

The current evidence base is limited by the lack of well-controlled prospective longitudinal studies and clinical studies including comorbid individuals. Future studies in humans examining the causal pathways and potential mechanisms of the association between cannabis use, CUD, and mood disorder comorbidity are crucial for optimizing harm reduction and treatment strategies.

Prevalence and correlates of cannabis use disorder among Australians using cannabis products to treat a medical condition

INTRODUCTION

Prior research has examined the prevalence and correlates of cannabis use disorder (CUD) in people who use cannabis; however, these are poorly described for people using cannabis for medical reasons.

METHODS

Data came from a 2018 to 2019 online, anonymous, cross-sectional survey of Australians reporting using either illicit or licit cannabis for medical reasons within the past year. Included were questions on demographics, current and lifetime patterns of cannabis use, clinical conditions for which medical cannabis was used, and individual criteria for CUD and cannabis withdrawal syndrome. Bayesian Horseshoe logistic regression models were used to identify covariates associated with meeting CUD DSM-5 conditions for any-CUD (≥2/11 criteria) and moderate-severe-CUD (≥4/11).

RESULTS

A total of 905 participants were included in the analysis. The majority (98%) used illicit cannabis products. Criteria for any-CUD criteria were met by 290 (32.0%), and 117 (12.9%) met criteria for moderate-severe-CUD. Tolerance (21%) and withdrawal (35%) were the most commonly met criteria. Correlates with the strongest association with CUD were inhaled route of administration [odds ratio (OR) = 2.96, 95% credible interval 1.11, 7.06], frequency of cannabis use (OR = 1.24, 1.11-1.35), proportion of cannabis for medical reasons (OR = 0.83, 0.74, 0.94), frequency of tobacco use (OR = 1.10, 1.03, 1.17), age (OR = 0.75, 0.64, 0.90) and pain as main clinical indication (OR = 0.58, 0.36, 1.00).

DISCUSSION AND CONCLUSIONS

Prevalence of CUD in medical cannabis users appears comparable to 'recreational' users, with many similar correlates. CUD was associated with using cannabis to treat mental health rather than pain conditions and inhaled over other routes of administration.

Prevalence and Correlates of Cannabis Use and Cannabis Use Disorder Among U.S. Veterans: Results From the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC-III)

OBJECTIVE

The authors sought to estimate the prevalence of past-12-month and lifetime cannabis use and cannabis use disorder among U.S. veterans; to describe demographic, substance use disorder, and psychiatric disorder correlates of nonmedical cannabis use and cannabis use disorder; and to explore differences in cannabis use and cannabis use disorder prevalence among veterans in states with and without medical marijuana laws.

METHODS

Participants were 3,119 respondents in the 2012-2013 National Epidemiologic Survey on Alcohol and Related Conditions-III (NESARC-III) who identified as U.S. veterans. Weighted prevalences were calculated. Logistic regression analyses tested associations of nonmedical cannabis use and cannabis use disorder with demographic and clinical correlates and examined whether prevalence differed by state legalization status.

RESULTS

The prevalences of any past-12-month cannabis use and cannabis use disorder were 7.3% and 1.8%, respectively. Lifetime prevalences were 32.5% and 5.7%, respectively. Past-12-month and lifetime cannabis use disorder prevalence estimates among nonmedical cannabis users were 24.4% and 17.4%, respectively. Sociodemographic correlates of nonmedical cannabis use and use disorder included younger age, male gender, being unmarried, lower income, and residing in a state with medical marijuana laws. Nonmedical cannabis use and use disorder were associated with most psychiatric and substance use disorders examined.

CONCLUSIONS

Among veterans, the odds of nonmedical cannabis use and use disorder were elevated among vulnerable subgroups, including those with lower income or psychiatric disorders and among survey participants residing in states with medical marijuana laws. The study findings highlight the need for clinical attention (e.g., screening, assessment) and ongoing monitoring among veterans in the context of increasing legalization of cannabis.

Is alcohol use associated with psychological treatment attendance and clinical outcomes?

OBJECTIVES

To investigate associations between alcohol use, psychological treatment attendance, and clinical outcomes.

METHODS

We analysed electronic health records for N = 7,986 patients accessing psychological treatment for common mental disorders. Data were collected for pre-treatment alcohol use (average units per week) and severity of dependence (SDS), number of therapy contacts attended, pre- and post-treatment anxiety (GAD-7), and depression (PHQ-9) symptom severity. Hierarchical regression was used to examine associations between alcohol use/dependence and post-treatment symptom severity controlling for intake severity and relevant confounders.

RESULTS

After controlling for confounders, alcohol use had significant nonlinear associations with pre-treatment depression severity (R²  = .54, p < .01, cubic trend), and post-treatment anxiety (R²  = .23, p < .01, quadratic trend). Alcohol use was not significantly associated with intake anxiety, post-treatment depression or treatment duration. SDS was not significantly associated with depression severity, alcohol severity, or total contacts after controlling for confounders.

CONCLUSION

Alcohol users are just as likely to engage in and benefit from evidence-based psychological treatments for depression in primary care. A nonlinear association between alcohol use and anxiety treatment outcomes indicates that light-to-moderate drinkers have some shared characteristic that favours treatment response.

PRACTITIONER POINTS

Depression and anxiety problems often co-occur with alcohol use and dependence. Conventional wisdom in the field suggests that heavy alcohol users may not engage well or benefit from psychological therapies for depression and anxiety. We found no empirical support for the above assumptions in a large clinical sample. Alcohol consumption was not significantly associated with treatment attendance or depression treatment outcomes. A nonlinear association between alcohol use and anxiety outcomes suggests that moderate drinkers may have some shared characteristic that favours treatment response.

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.

CANreduce 2.0 Adherence-Focused Guidance for Internet Self-Help Among Cannabis Users: Three-Arm Randomized Controlled Trial

Background

Despite increasing demand for treatment among cannabis users in many countries, most users are not in treatment. Internet-based self-help offers an alternative for those hesitant to seek face-to-face therapy, though low effectiveness and adherence issues often arise.

Objective

Through adherence-focused guidance enhancement, we aimed to increase adherence to and the effectiveness of internet-based self-help among cannabis users.

Methods

From July 2016 to May 2019, cannabis users (n=775; male: 406/575, 70.6%, female: 169/575, 29.4%; age: mean 28.3 years) not in treatment were recruited from the general population and were randomly assigned to (1) an adherence-focused guidance enhancement internet-based self-help intervention with social presence, (2) a similar intervention with an impersonal service team, and (3) access to internet as usual. Controls who were placed on a waiting list for the full intervention after 3 months underwent an assessment and had access to internet as usual. The primary outcome measurement was cannabis-use days over the preceding 30 days. Secondary outcomes included cannabis-dependence severity, changes in common mental disorder symptoms, and intervention adherence. Differences between the study arms in primary and secondary continuous outcome variables at baseline, posttreatment, and follow-up were tested using pooled linear models.

Results

All groups exhibited reduced cannabis-use days after 3 months (social presence: –8.2 days; service team: –9.8 days; internet as usual: –4.2 days). The participants in the service team group (P=.01, d=.60) reported significantly fewer cannabis-use days than those in the internet as usual group; the reduction of cannabis use in the social presence group was not significant (P=.07, d=.40). There was no significant difference between the 2 intervention groups regarding cannabis-use reduction. The service team group also exhibited superior improvements in cannabis-use disorder, cannabis-dependence severity, and general anxiety symptoms after 3 months to those in the internet as usual group.

Conclusions

The adherence-focused guidance enhancement internet-based self-help intervention with an impersonal service team significantly reduced cannabis use, cannabis-use disorder, dependence severity, and general anxiety symptoms.

Trial Registration

ISRCTN Registry ISRCTN11086185; http://www.isrctn.com/ISRCTN11086185

Prevalence and correlates of non-daily and daily cannabis use among persons 15 years and older in South Africa: results of a national survey in 2017

Background

The study aimed to assess the prevalence and correlates of non-daily and daily cannabis use among persons 15 years and older in South Africa.

Method

In a national cross-sectional 2017 survey, 39,207 persons 15 years and older (Median = 34 years) responded to a questionnaire on cannabis use and health variables. Multinominal logistic regression was used to assess the determinants of nondaily and daily cannabis use among the general population and logistic regression for the determinants of daily cannabis use among active cannabis users.

Results

Results indicate that 5.0% of the participants engaged in non-daily and 2.8% in daily cannabis use in the past 3 months. In adjusted multinomial logistic regression analysis, male sex, Grade 8–11 education, Coloureds, alcohol use disorder, never married, and other drug use were positively associated with daily cannabis use while not in not labour force was negatively associated with daily cannabis use. Moreover, male sex, never married, alcohol use disorder, and other drug use were positively, while physical multimorbidity was negatively associated with nondaily cannabis use. In adjusted logistic regression, compared to nondaily cannabis users, daily cannabis users were more likely male and were less likely not in the labour force and were less likely using other drugs.

Conclusion

About one in ten participants had used cannabis in the past 3 months in South Africa. Several sociodemographic and health indicators were identified that were associated with non-daily and/or daily cannabis use.

Cannabis use and cannabis use disorder

Cannabis use disorder (CUD) is an underappreciated risk of using cannabis that affects ~10% of the 193 million cannabis users worldwide. The individual and public health burdens are less than those of other forms of drug use, but CUD accounts for a substantial proportion of persons seeking treatment for drug use disorders owing to the high global prevalence of cannabis use. Cognitive behavioural therapy, motivational enhancement therapy and contingency management can substantially reduce cannabis use and cannabis-related problems, but enduring abstinence is not a common outcome. No pharmacotherapies have been approved for cannabis use or CUD, although a number of drug classes (such as cannabinoid agonists) have shown promise and require more rigorous evaluation. Treatment of cannabis use and CUD is often complicated by comorbid mental health and other substance use disorders. The legalization of non-medical cannabis use in some high-income countries may increase the prevalence of CUD by making more potent cannabis products more readily available at a lower price. States that legalize medical and non-medical cannabis use should inform users about the risks of CUD and provide information on how to obtain assistance if they develop cannabis-related mental and/or physical health problems.

Comorbid Cannabis Use Disorder with Major Depression and Generalized Anxiety Disorder: A Systematic Review with Meta-analysis of Nationally Representative Epidemiological Surveys

BACKGROUND

Studies have shown a high degree of comorbidity between cannabis use disorder (CUD) and other mental illnesses. However, there is a paucity of research on the comorbidity between CUD with major depression (MD) and generalized anxiety disorder (GAD). This systematic review with meta-analysis aimed to assess the prevalence and strength of association between co-morbid CUD with MD and GAD.

METHODS

An extensive search of Medline, CINAHL, PsycINFO, EMBASE, and grey literature were conducted to cover articles published between January 1^st, 1980, and July 31^st, 2020. Inclusion criteria were publications in English Language, original research, nationally representative samples, and non-clinical randomly selected adult populations. A systematic review and meta-analysis for the prevalence and ORs for comorbid CUD with MD or GAD were done.

RESULTS

A total of 67 articles were identified by the electronic searches. A full-text review yielded 8 publications on nationally representative epidemiological surveys. 12-month and lifetime comorbidity estimates were extracted and used for the meta-analysis. CUD was strongly associated with MDE (OR 3.22; 2.31 - 4.49) and with GAD (OR 2.99; 2.14 - 4.16).

LIMITATIONS

Limitations of this study include the heterogeneity observed due to the combination of studies from different geographic regions with different modifications of diagnostic criteria and varied response rates. This was addressed with a random-effects model.

CONCLUSION

This review confirms the evidence of high prevalence and a 3-fold comorbid association between CUD with MD and CUD with GAD. Implementation of evidence-based policy interventions with effective, integrated management of comorbid CUDs with psychiatric disorders may contribute to positive patient outcomes.

Past Year Cannabis Use Among Norwegian Adolescents: Time Trends Based on the Ungdata Surveys 2010-2019

Aims: To describe trends in cannabis use from 2010 to 2019 among Norwegian adolescents and relate these to individual- and municipal-level variables. Design: Data from nationwide repeated cross-sectional surveys collected in 2010-2013 (T1), 2014-2016 (T2), and 2017-2019 (T3) were used to describe secular trends in proportions of adolescent cannabis use. Setting: Cross-sectional surveys in 410 of the total 428 municipalities of Norway. Participants: A total of 628,678 survey responses from adolescents aged ~13-19 years of age, in which 566,912 survey responses were eligible for analyses, representing data from 340 municipalities. Measurements: Respondent's past year cannabis use, time, gender, school grade, municipality, geographical location, and municipality population. Findings: Boys reported overall higher cannabis use, with ~2:1 gender ratio for any past year cannabis use and a 3:1 gender ratio for frequent cannabis use. Adolescents in Eastern Norway reported higher cannabis use compared with other areas in the country, and adolescents from municipalities with a higher population size reported higher rates of cannabis use than smaller municipalities. A gradual increase in cannabis use from T1 to T3 was found in Eastern Norway and in the largest municipalities. More generally, proportions of past year cannabis use showed a marked increase from T2 to T3 across genders, grade/age groups, geographical location, and municipality population, with few exceptions. Conclusions: Our findings indicate that proportions of past year cannabis use have increased among Norwegian adolescents in recent years. Preventive interventions to hinder initiation of cannabis use, as well as measures to address frequent cannabis use among Norwegian adolescents, are needed.

DRD4, DRD2, DAT1, and ANKK1 Genes Polymorphisms in Patients with Dual Diagnosis of Polysubstance Addictions

Background: Approximately 25–50% of people diagnosed with substance use disorder experience psychiatric disorders, and this percentage is even higher if subclinical psychopathological symptomatology is taken into consideration. ”Dual diagnosis” implies the comorbidity of two disorders (mental disorder and addiction), but in a clinical setting, numerous dual diagnoses involve multiple addictions (polysubstance use means the concurrent use of more than one psychoactive substance). Clinical observations and epidemiological studies showed that the use of stimulants in combination with other substances results in additional risks. Apart from the clinical significance of the specificity of stimulants used in combination with other substances, only non-exhaustive research on the specificity of this comorbidity has been performed to date. The aim of the study was to analyze polymorphisms of the genes (DRD4 VNTR in exon III Ex3, DRD2 rs1076560, rs1800498, rs1079597, rs6276, as well as in the PROM promoter region (rs1799732, ANKK1 Tag1A rs1800497, DAT) in a group of patients diagnosed with polysubstance use disorder, including addiction to stimulants, and the co-occurrence of specific mental disorders in a group of patients diagnosed with polysubstance use disorder, including addiction to stimulants, compared to the group of patients diagnosed with polysubstance use disorder. Methods: The study group consisted of 601 male volunteers with psychoactive substance dependence (n = 300) and non-dependent controls (n = 301). The genomic DNA was extracted from venous blood using standard procedures. Genotyping was conducted with the real-time PCR method. All computations were performed using STATISTICA 13. Results: Psychotic disorders were significantly more common in the group of males with polysubstance addiction, including addiction to stimulants, compared to the group of males with polysubstance addiction without addiction to stimulants. In our own research, different statistical significances were found in the frequency of the DRD4 Ex3 gene polymorphism: s/s was more common in the study group. Psychotic disorders were more common in people addicted to stimulants compared to people addicted to other substances. Conclusions: In our study, psychotic disorders occurred more frequently in the study group of patients with polysubstance addiction, including addiction to stimulants, compared to the control group of patients with polysubstance addiction, but with no addiction to stimulants. Different statistical significances were found in the frequency of the DRD4 Ex3 gene polymorphism: s/s was more common in the study group, while the l/l genotype was less frequent in the study group. In DRD2 PROM rs 1799732, the del allele occurred more often than the ins allele in the study group. In the DRD4 Ex3 gene polymorphism, the s allele was more common in the study group, and the l allele was less frequent. In the DRD4 Ex3 gene polymorphism for the s/s genotype, psychotic disorders and generalized anxiety were more common, while for the s/l and l/l genotype, they were less frequent. The DRD4 Ex3 polymorphism s alleles were more common for depressive episode, dysthymia, and psychotic disorders as well as generalized anxiety disorder. We see a clear genetic aspect here. However, we want to be careful and draw no definite conclusions.

Prevalence of comorbid substance use in major depressive disorder in community and clinical settings, 1990-2019: Systematic review and meta-analysis

BACKGROUND

Comorbidity between Substance Use Disorders (SUDs) and major depression is highly prevalent. This systematic review and meta-analysis aimed to estimate the prevalence of SUDs in subjects diagnosed with a major depressive disorder (MDD) in community, inpatient and outpatient settings.

METHODS

A comprehensive literature search of Medline, EMBASE, PsycINFO and CINAHL databases was conducted from 1990 to 2019. Prevalence of co-morbid SUDs and MDD were extracted and odds ratios (ORs) were calculated using random effects meta-analysis.

RESULTS

There were 48 articles identified by electronic searches with a total sample size of 348,550 subjects that yielded 14 unique epidemiological studies, 2 national case registry studies, 7 large cohort studies and 20 clinical studies using in- or out-patients. The prevalence of any SUD in individuals with MDD was 0.250. Maximum prevalence was found with alcohol use disorder (0.208), followed by illicit drug use disorder (0.118) and cannabis use disorder (0.117). Meta-analysis showed the pooled variance of any AUD in men with MDD was 36%, which was significantly higher than that for females with MDD (19%, OR 2.628 95% CI 2.502, 2.760).

CONCLUSIONS

Few studies were published over the last decade so current prevalence rates of SUD in MDD are needed. Meta-analysis revealed that SUDs in MDD are highly prevalent and rates have not changed over time. The persistently high prevalence suggests there is an urgent need for more informative studies to help develop better prevention and treatment options for reducing prevalence of SUDs in persons with major depression and co-morbid disorders.

Attentional bias, craving and cannabis use in an inpatient sample of adolescents and young adults diagnosed with cannabis use disorder: The moderating role of cognitive control

Motivational processes like attentional bias and craving have been related to substance use. However, results are inconclusive. The present cross-sectional study was designed to replicate and extend previous research by investigating the relationships between attentional bias, craving, cognitive control and (severity of) cannabis use in a sample of inpatient adolescents and young adults (aged 18-30) diagnosed with CUD according to DSM-5. Contrary to expectations, our sample did not show attentional bias for cannabis words, neither did attentional bias correlate with craving, cognitive control or (severity of) cannabis use. In line with our hypotheses, however, increased session-induced craving was correlated to more daily cannabis use and reduced cognitive control. Furthermore, participants who displayed reduced cognitive control used more cannabis per day. A bootstrapped hierarchical regression model showed that, contrary to expectations, cognitive control did not modulate the relationships between attentional bias, craving and cannabis use. This study highlights the unique role of craving in relation to cannabis use and extends previous findings that cognitive control appears to have no moderating role regarding cannabis use disorder. Based on our results, it might well be that the underlying mechanisms of cannabis use disorder differ from those in other substance use disorders.

Cannabis-Related Impairment and Social Anxiety: The Role of Use to Manage Negative and Positive Affect in Social Situations

Background and Objectives: Individuals with elevated social anxiety are thought to be at high risk for developing cannabis-related problems because they use cannabis to cope with anxiety-provoking social situations. Social anxiety is unique among the anxiety conditions in that it is characterized by both elevated negative affect (NA) and lower positive affect (PA). Yet it is unclear whether persons with elevated social anxiety use cannabis to decrease their NA or to increase their PA. Methods: This study examined the role of PA and NA (including cannabis use to increase PA and to decrease NA in social situations) on cannabis use frequency and related problems among current (past three-month) cannabis users (N = 278). Results: Social anxiety was significantly correlated with NA, PA, cannabis use to decrease NA, and use to increase PA. Serial mediation analyses tested the paths between social anxiety, affect, use to manage affect, typical cannabis use frequency, and cannabis use-related problems. Contrary to prediction, social anxiety was not indirectly related to use frequency or related problems via NA or PA generally. Rather, social anxiety was indirectly related to cannabis problems via the serial effect of use to cope with NA and typical use frequency and via the serial effect of use to increase PA and typical use frequency. Conclusions/Importance: Social anxiety may be associated with using cannabis to decrease NA and increase PA specifically in social situations, which increases cannabis use frequency and thus, problem risk.

Determining Risks for Cannabis Use Disorder in the Face of Changing Legal Policies

Purpose of review

This review aims to summarize and critically evaluate the current literature on the associations between individual and socio-cultural factors that increase risk for cannabis use disorder (CUD), and policy change.

Recent findings

Epidemiological studies show that areas with permissive legal cannabis climates are associated with greater individual risk factors for CUD. This includes: (1) higher rates of edible consumption and vaping, (2) higher delta-9-tetrahydrocannabinol (THC) potency and lower cannabidiol (CBD) levels, and, (3) younger age of initiation of use.

Summary

A change in the socio-cultural level, such as shifts in the legalization of cannabis, could interact with individual-level factors in their associations with CUD. There is currently a lack of empirical studies that evaluate this interaction. We propose that future research consider a bioecological framework for CUD to allow for a comprehensive understanding of the effects of legal climate that could inform policy and clinical practice.

Is there a relationship between cannabis use problems, emotion dysregulation, and mental health problems among adults with chronic pain?

Cannabis is often used to manage pain among persons who suffer from chronic pain. Yet, despite much literature suggesting cannabis use problems are associated with mental health problems, little work has examined mechanisms of this relationship among a chronic pain population. Chronic pain is also associated with emotion dysregulation. Individuals with chronic pain who experience cannabis use problems may have less capacity to regulate negative emotions, which could relate to greater anxiety, depression, and suicidal ideation. Thus, the current study explored whether emotion dysregulation explained, in part, the relation between cannabis use problems and anxiety, depression, and suicidal ideation among adults with chronic pain. Participants were 431 opioid-using adults with current moderate to severe chronic pain, 176 were current cannabis users, of which 30.20% reported cannabis use problems. Results indicated a significant indirect relationship between cannabis use problems and anxiety [95% CI (.03, .05)], depression [95% CI (.03, .06)], and suicidal ideation [95% CI (.01, .01)] via emotion dysregulation. Tests of specificity suggested potential for a bi-directional effect for suicidal ideation (p < .001). Initial findings suggest that emotion dysregulation may be an important mechanism in the relationship between cannabis use problems and mental health among adults with chronic pain.

An update on cannabis use disorder with comment on the impact of policy related to therapeutic and recreational cannabis use

Confusion and controversy related to the potential for cannabis use to cause harm, or alternatively to provide benefit, continues globally. This issue has grown in intensity and importance with the increased recognition of the public health implications related to the escalation of the legalization of cannabis and cannabinoid products. This selective overview and commentary attempt to succinctly convey what is known about one potential consequence of cannabis use, the development of cannabis use disorder (CUD). Such knowledge may help guide a reasonable and objective public health perspective on the potential impact of cannabis use and CUD. Current scientific data and clinical observation strongly support the contention that cannabis use, like the use of other substances such as alcohol, opioids, stimulants, and tobacco, can develop into a use disorder (addiction) with important clinical consequences. Epidemiological data indicate that the majority of those who use cannabis do not have problems related to their use, but a substantial subset (10-30%) do report experiencing symptoms and consequences consistent with a CUD. Treatment seeking for CUD comprises a substantial proportion of all substance use treatment admissions, yet treatment response rates show much room for improvement. Changing cannabis policies related to its therapeutic and recreational use are likely to impact the development of CUD and its course; however, definitive data on such effects are not yet available. Clearly, the development of more effective prevention and treatment strategies is needed for those vulnerable to developing a CUD and for those with a CUD.

Measuring Unmet Demand for Alcohol and Other Drug Treatment: The Application of an Australian Population-Based Planning Model

OBJECTIVE

The estimation of demand for treatment is one of the important elements in planning for alcohol and other drug treatment services. This article reports on a demand-projection model used in Australia to estimate the extent of unmet treatment demand by drug type.

METHOD

The model incorporated the prevalence of substance use disorders (by drug type and age), with the application of a severity distribution, which distributed the substance abuse disorders into three disability categories: mild, moderate, and severe. The application of treatment rates derived from expert judgments reflecting the proportion of people within disability categories who would be suitable for, likely to seek, and benefit from treatment. Sensitivity analyses incorporating variations to the severity distributions and treatment rates were applied, along with adjustment for polydrug use.

RESULTS

The estimate for treatment demand for Australia varied between a low of 411,740 people and a high of 755,557 people. The most sensitive parameter is the expected treatment-seeking rate. Given that approximately 200,000 to 230,000 people are currently in treatment, this represents a met demand of between 26.8% and 56.4%.

CONCLUSIONS

There is insufficient alcohol and drug treatment available to meet the demand in Australia, despite Australia's relatively high met demand, when compared with other countries.

Integrated cognitive behavioral therapy for comorbid cannabis use and anxiety disorders: A pilot randomized controlled trial

Cannabis use disorder (CUD) is the most common illicit substance use disorder and individuals with CUD have high rates of comorbid anxiety disorders. Comorbidity between CUD and anxiety disorders is of public health relevance given that although motivation enhancement therapy (MET) combined with cognitive-behavioral therapy (CBT) is an efficacious intervention for CUD, outcomes are worse for patients with elevated anxiety. The current study tested the acceptability and efficacy of the integration of a transdiagnostic anxiety CBT (i.e., treatment of patients with any anxiety disorder) with MET-CBT (integrated cannabis and anxiety reduction treatment, or ICART) for CUD compared to MET-CBT alone. Treatment-seeking cannabis users (56.4% male, M_age = 23.2, 63.3% non-Hispanic White) with CUD and at least one comorbid anxiety disorder were randomly assigned to ICART (n = 27) or MET-CBT (n = 28). Patients in the ICART condition attended significantly more treatment sessions than those in the MET-CBT condition. Patients in the ICART condition were more likely to be abstinent post-treatment than those in MET-CBT. Further, treatment produced decreases in cannabis use and related problems. Notably, therapy type did not moderate the impact of treatment on frequency of use and related problems. Together, these data suggest that ICART may be at least as efficacious as a gold-standard psychosocial CUD treatment, MET-CBT, for a difficult-to-treat subpopulation of cannabis users.

Cannabis regulatory science: risk-benefit considerations for mental disorders

The evolving legal cannabis landscape in the US continues to present novel regulatory challenges that necessitate the development of a Cannabis Regulatory Science. Two specific issues of concern within Cannabis Regulatory Science are (1) the impact that cannabis use has on the incidence, prevalence, and severity of mental disorders, and (2) how cannabis laws and regulations modify this impact. This paper first provides several conceptual points that are useful for evaluating the relationship between cannabis use and mental disorders. Second, it selectively reviews and comments on data relevant to the relationship between cannabis use and depression, several forms of anxiety, post-traumatic stress disorder, schizophrenia, and bipolar disorder. Next, regulatory and public health parallels between the nascent cannabis industry and the pharmaceutical, tobacco, and alcohol industries are discussed. The focus is on specific types of industry practices that may harm those with or at risk for mental disorders. Recommendations are then offered for legal cannabis regulations that could mitigate this harm. Last, future research goals are discussed for building the field of Cannabis Regulatory Science and addressing the potential negative impact of cannabis on those with mental disorders.

The efficacy of computerized interventions to reduce cannabis use: A systematic review and meta-analysis

BACKGROUND AND AIMS

Cannabis is the most widely consumed illicit drug. Although it is too early to confirm the impact of legalization, the use of cannabis appears to be on the rise in some countries due to its authorization for medical/recreational purposes. Among different types of therapeutic approaches to reduce cannabis use, computerized interventions are becoming a new treatment option. To assess their efficacy, a systematic review and meta-analysis was conducted.

METHODS

A systematic review and meta-analysis was performed employing randomized controlled clinical trials indexed in MEDLINE and PsycINFO. The principal outcome measure was cannabis use, and the secondary one was the use of other substances during interventions. A subgroup analysis was conducted by length of follow-up, number of sessions, age group, type of analysis, and type of control condition.

RESULTS

The meta-analysis included nine studies with 2963 participants. Computerized interventions resulted in significant reductions in the use of cannabis (standardized mean difference [SMD]: -0.19; 95% CI: -0.26, -0.11) and other substances (SMD: -0.27; 95% CI: -0.46, -0.08).

CONCLUSIONS

Computerized interventions examined in the present study reduced the frequency of cannabis and other substance use. Limitations included the recalculation of dichotomous and continuous data as SMD and the lower number of studies included in the secondary outcome. Computerized interventions could be a viable option to reduce cannabis use.

Nineteen and Up study (19Up): understanding pathways to mental health disorders in young Australian twins

PURPOSE

The Nineteen and Up study (19Up) assessed a range of mental health and behavioural problems and associated risk factors in a genetically informative Australian cohort of young adult twins and their non-twin siblings. As such, 19Up enables detailed investigation of genetic and environmental pathways to mental illness and substance misuse within the Brisbane Longitudinal Twin Sample (BLTS).

PARTICIPANTS

Twins and their non-twin siblings from Queensland, Australia; mostly from European ancestry. Data were collected between 2009 and 2016 on 2773 participants (age range 18-38, 57.8% female, 372 complete monozygotic pairs, 493 dizygotic pairs, 640 non-twin siblings, 403 singleton twins).

FINDINGS TO DATE

A structured clinical assessment (Composite International Diagnostic Interview) was used to collect lifetime prevalence of diagnostic statistical manual (4th edition) (DSM-IV) diagnoses of major depressive disorder, (hypo)mania, social anxiety, cannabis use disorder, alcohol use disorder, panic disorder and psychotic symptoms. Here, we further describe the comorbidities and ages of onset for these mental disorders. Notably, two-thirds of the sample reported one or more lifetime mental disorder.In addition, the 19Up study assessed general health, drug use, work activity, education level, personality, migraine/headaches, suicidal thoughts, attention deficit hyperactivity disorder (ADHD) symptomatology, sleep-wake patterns, romantic preferences, friendships, familial environment, stress, anorexia and bulimia as well as baldness, acne, asthma, endometriosis, joint flexibility and internet use.The overlap with previous waves of the BLTS means that 84% of the 19Up participants are genotyped, 36% imaged using multimodal MRI and most have been assessed for psychological symptoms at up to four time points. Furthermore, IQ is available for 57%, parental report of ADHD symptomatology for 100% and electroencephalography for 30%.

FUTURE PLANS

The 19Up study complements a phenotypically rich, longitudinal collection of environmental and psychological risk factors. Future publications will explore hypotheses related to disease onset and development across the waves of the cohort. A follow-up study at 25+years is ongoing.

DSM-5 cannabis use disorder in the National Epidemiologic Survey on Alcohol and Related Conditions-III: Gender-specific profiles

OBJECTIVE

The objective of this study was to present current information on the prevalence, correlates, comorbidity and quality of life among men and women with cannabis use disorder (CUD).

METHODS

In 2012-2013, 36,309 respondents ≥18years old participated in face-to-face interviews in the National Epidemiologic Survey on Alcohol and Related Conditions-III.

RESULTS

Prevalence of 12-month CUD was greater among men (3.5%) than women (1.7%). Women experienced shorter duration from onset of cannabis use to onset of CUD than men (mean=5.8years, men; mean=4.7years, women). In both men and women, prevalences of CUD were greater among young adults, Blacks, and those with lower income and greater among Native American women relative to White women. CUD was highly comorbid with other substance use disorders, PTSD, ASPD and borderline and schizotypal PDs for men and women. Quality of life for individuals with CUD was low regardless of gender.

CONCLUSIONS

DSM-5 CUD among men and women is highly prevalent, comorbid and characterized by low quality of life. Results highlighted the need for integrated treatment of CUD and comorbid disorders and the urgency of identifying and implementing effective prevention and intervention approaches, especially for those sociodemographic subgroups for which both men and women are at greater risk for the disorder.

Past year cannabis use and problematic cannabis use among adults by ethnicity in Ontario

BACKGROUND

Rates of cannabis use differ around the world; in Ontario, the rate of use has been stable since about 2005. Understanding which population groups are at greater risk for problematic cannabis use can help reduce long-term health effects and service expenses. The aim of this study was to explore differences in cannabis use among Canadian adults of different ethnic origins living in Ontario.

METHODS

Data are based on telephone interviews with 11,560 respondents and are derived from multiple cycles (2005-2011) of the Centre for Addiction and Mental Health's (CAMH) Monitor survey, an ongoing cross-sectional survey of adults in Ontario, Canada, aged 18 years and older. Data were analyzed using bivariate cross-tabulations and logistic regression. Problematic cannabis use was determined with a score of 8+ on the ASSIST-CIS to identify moderate/high problematic users.

RESULTS

Lifetime, past year and problematic cannabis use (in the past 3 months) occurs among all ethnic groups: Canadian, East Asian, South East Asian, South Asian, Caribbean, African, East European, South European, North European, and Central West European. When compared to the Canadian group the odds of past year cannabis use was significantly lower for East Asians and South Asians, but higher for the Caribbean group. Significantly higher odds of problematic cannabis use were found for Caribbeans and Northern Europeans compared to Canadians.

CONCLUSIONS

These results of this study provide an important basis for considering the possible impact of the impending legalization of cannabis in Canada among different ethnic groups.

Cannabis use during treatment for alcohol use disorders predicts alcohol treatment outcomes

AIMS

To compare post-treatment alcohol use between those who use cannabis and those who abstain during treatment for alcohol use disorders (AUD); and to examine potential cannabis use thresholds by comparing post-treatment alcohol use between four frequency groups of cannabis users relative to abstainers.

DESIGN

Secondary analyses of the Combined Pharmacotherapies and Behavioral Interventions (COMBINE) Study, a randomized control trial of AUD treatments. The current study compares longitudinal drinking data between those who used cannabis versus those who abstained during COMBINE treatment.

SETTING

The COMBINE Study treatments were delivered on an out-patient basis for 16 weeks. The current analyses include 206 cannabis users and 999 cannabis abstainers.

PARTICIPANTS

All participants met diagnosis of primary alcohol dependence (n = 1383).

MEASUREMENTS

Primary exposures were any cannabis use and quartiles of cannabis use (Q1: 1-4 use days during treatment, Q2: 5-9 days, Q3: 10-44 days, Q4: 45-112 days). Outcomes were percentage of days abstinent from alcohol (PDA), drinks per drinking day (DPDD) and percentage of heavy drinking days (PHD), all measured at treatment end and 1 year post-treatment.

FINDINGS

Compared with no cannabis use, any cannabis use during treatment was associated with 4.35% [95% confidence interval (CI) = -8.68, -0.02], or approximately 4 fewer alcohol abstinent days at the end of treatment. This association weakened by 1 year post-treatment (95% CI = -9.78, 0.54). Compared with no cannabis use, only those in the second quartile of cannabis use (those who used once or twice per month during treatment) had 8.81% (95% CI = -17.00, -0.63), or approximately 10 fewer days alcohol abstinent at end of treatment, and 11.82% (95% CI = -21.56, -2.07), or approximately 13 fewer alcohol abstinent days 1 year post-treatment. Neither any cannabis use nor quartiles were associated with DPDD or PHD at either time-point.

CONCLUSIONS

Among individuals in alcohol treatment, any cannabis use (compared with none) is related to a significantly lower percentage of days abstinent from alcohol post-treatment, although only among those who used cannabis once or twice per month.

Comorbidity of bipolar and substance use disorders in national surveys of general populations, 1990-2015: Systematic review and meta-analysis

BACKGROUND

Substance use disorders (SUDs) are common in people with a bipolar disorder (BD). This systematic review and meta-analysis aimed to estimate the prevalence rates of SUDs in persons with BD based on national or international surveys of household populations.

METHODS

Studies published from 1990 to Dec 31, 2015 were identified from MEDLINE, EMBASE. psychINFO, and CINAHL databases and reference lists. We calculated prevalence rates and conducted meta-analysis with random-effects model.

RESULTS

We identified 9 unique surveys of which two surveys were repeated 10 years later using independent samples. The total sample size was 218,397 subjects. The mean prevalence for any illicit drug use disorder was 17%, for alcohol use disorder (AUD) it was 24% and SUD it was 33%. The strongest associations were found between BD and illicit drug use (pooled odds ratio (OR) 4.96, 95% CI 3.98-6.17) followed closely by BD and AUD (OR 4.09, 95% CI 3.37-4.96). The association was higher for BD respondents using illicit drugs compared to bipolar II respondents (ORs 7.48 vs. 3.30).

LIMITATIONS

Some of the meta-analysis grouped illicit substances together without taking into consideration types of substance use which may differ widely between countries and over time. All included studies were cross-sectional so onset and causality can not be determined.

CONCLUSIONS

The meta-analysis revealed that people with an alcohol use disorder were 4.1 times of greater risk of having a BD compared to those without an AUD. The risks were even higher for illicit drug users where they were 5.0 times of greater risk of having BD compared to non-users. These data confirm strong associations between co-occurring SUDs and BD, indicating a need for more informative studies to help develop better interventions in treating persons with BD and comorbid SUDs.

Integrated Exposure-Based Therapy for Co-Occurring Post Traumatic Stress Disorder (PTSD) and Substance Dependence: Predictors of Change in PTSD Symptom Severity

This paper examines factors associated with change in PTSD symptom severity among individuals randomised to receive an integrated exposure-based psychotherapy for PTSD and substance dependence–Concurrent Treatment of PTSD and Substance Use Disorders Using Prolonged Exposure (COPE). Outcomes examined include change in PTSD symptom severity as measured by the Clinician Administered PTSD Scale (CAPS), and the reliability and clinical significance of change in PTSD symptom severity. Factors examined include patient baseline characteristics, treatment characteristics, and events over follow-up. The mean difference in CAPS score was 38.24 (SE 4.81). Approximately half (49.1%) demonstrated a reliable and clinically significant improvement in PTSD symptom severity. No one was classified as having demonstrated clinically significant worsening of symptoms. Three independent predictors of reductions in PTSD symptom severity were identified: baseline PTSD symptom severity (β 0.77, SE 0.23, p = 0.001), number of traumas experienced prior to baseline (β −0.30, SE 0.15, p = 0.049), and number of sessions attended (β 2.05, SE 0.87, p = 0.024). The present study provides further evidence regarding the safety of the COPE treatment and factors associated with improvement in PTSD symptom severity. The identification of only a small number of predictors of the outcome points to the broad applicability of the COPE treatment to PTSD and substance use disorder (SUD) patients.

Substance use disorders comorbid with mood and anxiety disorders in the Australian general population

INTRODUCTION AND AIMS

Substance use disorders (SUDs) are common and frequently co-occur with mood and anxiety disorders. This paper provides a detailed analysis of patterns, prevalence and correlates of mood and anxiety disorders among those with a (i) pure SUD; (ii) SUD plus a mood or anxiety disorder (SUDs + 1); and (iii) SUD plus a mood and anxiety disorder (SUDs + 2).

DESIGN AND METHODS

Data came from the 2007 National Survey of Mental Health and Wellbeing; a nationally representative household survey of 8841 Australians aged 16-85 years.

RESULTS

The 12-month prevalence of SUDs was 5.1%. Of those with a 12-month SUD, 65% met the criteria for pure SUDs, 19% for SUDs + 1 and 16% for SUDs + 2. Major depression was the most common mood disorder in both comorbid groups. One-third of SUDs + 1 experienced social phobia, while over half of SUDs + 2 experienced generalised anxiety disorder. Compared with pure SUDs, SUDs + 1 experienced two times more and SUDs + 2 experienced over four times more days out of role in the preceding 30 days. Both comorbid groups were more likely to experience severe levels of impairment. SUDs + 2 were over 18 times more likely to experience suicidal thoughts in the same year. SUDs + 1 were over three times and SUDs + 2 were over 10 times more likely to have had one or more consultations with a health professional in the previous year.

DISCUSSIONS AND CONCLUSIONS

These findings highlight the complexities inherent with responding to and treating multiple comorbidities among substance users and emphasise the need for coordinated, cohesive responses from drug and alcohol treatment services.[Prior K, Mills K, Ross J, Teesson M. Substance use disorders comorbid with mood and anxiety disorders in the Australian general population. Drug Alcohol Rev 2017;36:317-324].

Cannabis Use in Adolescence and Young Adulthood: A Review of Findings from the Victorian Adolescent Health Cohort Study

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.

Prevalence and Correlates of DSM-5 Cannabis Use Disorder, 2012-2013: Findings from the National Epidemiologic Survey on Alcohol and Related Conditions-III

OBJECTIVE

Attitudes toward marijuana are changing, the prevalence of DSM-IV cannabis use disorder has increased, and DSM-5 modified the cannabis use disorder criteria. Therefore, updated information is needed on the prevalence, demographic characteristics, psychiatric comorbidity, disability, and treatment for DSM-5 cannabis use disorder.

METHOD

In 2012-2013, 36,309 participants ≥18 years old were interviewed in the National Epidemiologic Survey on Alcohol and Related Conditions-III. Psychiatric and substance use disorders were assessed with the Alcohol Use Disorders and Associated Disabilities Interview Schedule-5.

RESULTS

The prevalences of 12-month and lifetime cannabis use disorder were 2.5% and 6.3%. Among those with 12-month and lifetime diagnoses, the mean days of marijuana use per year were 225.3 (SE=5.7) and 274.2 (SE=3.8). The odds of 12-month and lifetime cannabis use disorder were higher for men, Native Americans, unmarried individuals, those with low incomes, and young adults (e.g., among those age 18-24 years versus ≥45: odds ratio for 12-month disorder, 7.2; 95% confidence interval, 5.5-9.5). Cannabis use disorder was associated with other substance use disorders, affective disorders, anxiety, and personality disorders. Twelve-month cannabis use disorder was associated with disability. As disorder severity increased, virtually all associations became stronger. Only 13.2% with lifetime cannabis use disorder participated in 12-step programs or professional treatment.

CONCLUSIONS

DSM-5 cannabis use disorder is prevalent, associated with comorbidity and disability, and largely untreated. Findings suggest the need to improve prevention and educate the public, professionals, and policy makers about possible harms associated with cannabis use disorders and available interventions.

Psychosocial interventions for cannabis use disorder

BACKGROUND

Cannabis use disorder is the most commonly reported illegal substance use disorder in the general population; although demand for assistance from health services is increasing internationally, only a minority of those with the disorder seek professional assistance. Treatment studies have been published, but pressure to establish public policy requires an updated systematic review of cannabis-specific treatments for adults.

OBJECTIVES

To evaluate the efficacy of psychosocial interventions for cannabis use disorder (compared with inactive control and/or alternative treatment) delivered to adults in an out-patient or community setting.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 6), MEDLINE, EMBASE, PsycINFO, the Cumulaive Index to Nursing and Allied Health Literature (CINAHL) and reference lists of articles. Searched literature included all articles published before July 2015.

SELECTION CRITERIA

All randomised controlled studies examining a psychosocial intervention for cannabis use disorder (without pharmacological intervention) in comparison with a minimal or inactive treatment control or alternative combinations of psychosocial interventions.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by The Cochrane Collaboration.

MAIN RESULTS

We included 23 randomised controlled trials involving 4045 participants. A total of 15 studies took place in the United States, two in Australia, two in Germany and one each in Switzerland, Canada, Brazil and Ireland. Investigators delivered treatments over approximately seven sessions (range, one to 14) for approximately 12 weeks (range, one to 56).Overall, risk of bias across studies was moderate, that is, no trial was at high risk of selection bias, attrition bias or reporting bias. Further, trials included a large total number of participants, and each trial ensured the fidelity of treatments provided. In contrast, because of the nature of the interventions provided, participant blinding was not possible, and reports of researcher blinding often were unclear or were not provided. Half of the reviewed studies included collateral verification or urinalysis to confirm self report data, leading to concern about performance and detection bias. Finally, concerns of other bias were based on relatively consistent lack of assessment of non-cannabis substance use or use of additional treatments before or during the trial period.A subset of studies provided sufficient detail for comparison of effects of any intervention versus inactive control on primary outcomes of interest at early follow-up (median, four months). Results showed moderate-quality evidence that approximately seven out of 10 intervention participants completed treatment as intended (effect size (ES) 0.71, 95% confidence interval (CI) 0.63 to 0.78, 11 studies, 1424 participants), and that those receiving psychosocial intervention used cannabis on fewer days compared with those given inactive control (mean difference (MD) 5.67, 95% CI 3.08 to 8.26, six studies, 1144 participants). In addition, low-quality evidence revealed that those receiving intervention were more likely to report point-prevalence abstinence (risk ratio (RR) 2.55, 95% CI 1.34 to 4.83, six studies, 1166 participants) and reported fewer symptoms of dependence (standardised mean difference (SMD) 4.15, 95% CI 1.67 to 6.63, four studies, 889 participants) and cannabis-related problems compared with those given inactive control (SMD 3.34, 95% CI 1.26 to 5.42, six studies, 2202 participants). Finally, very low-quality evidence indicated that those receiving intervention reported using fewer joints per day compared with those given inactive control (SMD 3.55, 95% CI 2.51 to 4.59, eight studies, 1600 participants). Notably, subgroup analyses found that interventions of more than four sessions delivered over longer than one month (high intensity) produced consistently improved outcomes (particularly in terms of cannabis use frequency and severity of dependence) in the short term as compared with low-intensity interventions.The most consistent evidence supports the use of cognitive-behavioural therapy (CBT), motivational enhancement therapy (MET) and particularly their combination for assisting with reduction of cannabis use frequency at early follow-up (MET: MD 4.45, 95% CI 1.90 to 7.00, four studies, 612 participants; CBT: MD 10.94, 95% CI 7.44 to 14.44, one study, 134 participants; MET + CBT: MD 7.38, 95% CI 3.18 to 11.57, three studies, 398 participants) and severity of dependence (MET: SMD 4.07, 95% CI 1.97 to 6.17, two studies, 316 participants; MET + CBT: SMD 7.89, 95% CI 0.93 to 14.85, three studies, 573 participants), although no particular intervention was consistently effective at nine-month follow-up or later. In addition, data from five out of six studies supported the utility of adding voucher-based incentives for cannabis-negative urines to enhance treatment effect on cannabis use frequency. A single study found contrasting results throughout a 12-month follow-up period, as post-treatment outcomes related to overall reduction in cannabis use frequency favoured CBT alone without the addition of abstinence-based or treatment adherence-based contingency management. In contrast, evidence of drug counselling, social support, relapse prevention and mindfulness meditation was weak because identified studies were few, information on treatment outcomes insufficient and rates of treatment adherence low. In line with treatments for other substance use, abstinence rates were relatively low overall, with approximately one-quarter of participants abstinent at final follow-up. Finally, three studies found that intervention was comparable with treatment as usual among participants in psychiatric clinics and reported no between-group differences in any of the included outcomes.

AUTHORS' CONCLUSIONS

Included studies were heterogeneous in many aspects, and important questions regarding the most effective duration, intensity and type of intervention were raised and partially resolved. Generalisability of findings was unclear, most notably because of the limited number of localities and homogeneous samples of treatment seekers. The rate of abstinence was low and unstable although comparable with treatments for other substance use. Psychosocial intervention was shown, in comparison with minimal treatment controls, to reduce frequency of use and severity of dependence in a fairly durable manner, at least in the short term. Among the included intervention types, an intensive intervention provided over more than four sessions based on the combination of MET and CBT with abstinence-based incentives was most consistently supported for treatment of cannabis use disorder.

No additive effect of cannabis on cognition in schizophrenia

BACKGROUND

We aimed to examine the association between lifetime cannabis use and estimates of both premorbid and current cognitive function in psychotic disorders in an Australian cohort.

METHODS

In an Australian multicenter cohort, 1237 participants with an established ICD-10 diagnosis of psychotic disorder were categorised according to history of lifetime cannabis use (non-users, n=354; cannabis users, n=221; cannabis dependency, n=662). Groups were analyzed according to available indices of cognitive ability: the National Adult Reading Test - Revised (NART-R) for ability prior to illness onset; and the Digit Symbol Coding Test (DSCT) for current ability. Two-way analysis of variance was conducted without any covariate, followed by a two-way analysis of covariance (using age, age at onset of psychiatric illness, premorbid IQ and the Socio-Economic Index for Areas (SEIFA) rankings).

RESULTS

Whilst there appeared to be a significant association between cannabis use and mean DSCT (higher DSCT scores in cannabis using groups) F(2,1080)=9.478, p<0.001, η2=0.017), once covariates were used in the analysis there were no significant differences between groups in mean DSCT scores (F(2,1011)=0.929, p=0.395, η2=0.002). Similarly there were no differences between groups in mean NART scores once, age, age at illness onset and SEIFA rankings were used as covariates (F(2,1032)=1.617, p=0.199, η2=0.003).

CONCLUSIONS

Confounding variables underpin the association between cannabis use and cognitive function in psychotic disorders. Taken together, it would appear that cannabis use or dependence has no additive effect on cognitive dysfunction in these disorders.

Cannabis use and anxiety: is stress the missing piece of the puzzle?

OBJECTIVE

Comorbidity between anxiety and cannabis use is common yet the nature of the association between these conditions is not clear. Four theories were assessed, and a fifth hypothesis tested to determine if the misattribution of stress symptomology plays a role in the association between state-anxiety and cannabis.

METHODS

Three-hundred-sixteen participants ranging in age from 18 to 71 years completed a short online questionnaire asking about their history of cannabis use and symptoms of stress and anxiety.

RESULTS

Past and current cannabis users reported higher incidence of lifetime anxiety than participants who had never used cannabis; however, these groups did not differ in state-anxiety, stress, or age of onset of anxiety. State-anxiety and stress were not associated with frequency of cannabis use, but reported use to self-medicate for anxiety was positively associated with all three. Path analyses indicated two different associations between anxiety and cannabis use, pre-existing and high state-anxiety was associated with (i) higher average levels of intoxication and, in turn, acute anxiety responses to cannabis use; (ii) frequency of cannabis use via the mediating effects of stress and self-medication.

CONCLUSION

None of the theories was fully supported by the findings. However, as cannabis users reporting self-medication for anxiety were found to be self-medicating stress symptomology, there was some support for the stress-misattribution hypothesis. With reported self-medication for anxiety being the strongest predictor of frequency of use, it is suggested that researchers, clinicians, and cannabis users pay greater attention to the overlap between stress and anxiety symptomology and the possible misinterpretation of these related but distinct conditions.

Cost benefit analysis of two policy options for cannabis: status quo and legalisation

Aims

To date there has been limited analysis of the economic costs and benefits associated with cannabis legalisation. This study redresses this gap. A cost benefit analysis of two cannabis policy options the status quo (where cannabis use is illegal) and a legalised–regulated option was conducted.

Method

A cost benefit analysis was used to value the costs and benefits of the two policies in monetary terms. Costs and benefits of each policy option were classified into five categories (direct intervention costs, costs or cost savings to other agencies, benefits or lost benefits to the individual or the family, other impacts on third parties, and adverse or spill over events). The results are expressed as a net social benefit (NSB).

Findings

The mean NSB per annum from Monte Carlo simulations (with the 5 and 95 percentiles) for the status quo was $294.6 million AUD ($201.1 to $392.7 million) not substantially different from the $234.2 million AUD ($136.4 to $331.1 million) for the legalised–regulated model which excludes government revenue as a benefit. When government revenue is included, the NSB for legalised–regulated is higher than for status quo. Sensitivity analyses demonstrate the significant impact of educational attainment and wellbeing as drivers for the NSB result.

Conclusion

Examining the percentiles around the two policy options, there appears to be no difference between the NSB for these two policy options. Economic analyses are essential for good public policy, providing information about the extent to which one policy is substantially economically favourable over another. In cannabis policy, for these two options this does not appear to be the case.

Cannabis dependence, cognitive control and attentional bias for cannabis words

One of the characteristics of people suffering from addictive behaviors is the tendency to be distracted by drug cues. This attentional bias for drug cues is thought to lead to increased craving and drug use, and may draw individuals into a vicious cycle of drug addiction. In the current study we developed a Dutch version of the cannabis Stroop task and measured attentional bias for cannabis words in a group of heavy cannabis users and matched controls. The classical Stroop task was used as a global measure of cognitive control and we examined the relationship between cognitive control, cannabis-related problems, cannabis craving and cannabis attentional bias. Using our version of the cannabis Stroop task, a group of heavy cannabis users showed attentional bias to cannabis words, whereas a control group of non-users did not. Furthermore, within the group of cannabis users, those who were clinically recognized as dependent showed a stronger attentional bias than the heavy, non-dependent users. Cannabis users who displayed reduced cognitive control (as measured with the classical Stroop task) showed increased session-induced craving. Contrary to expectations, however, cognitive control did not appear to modulate the relationship between attentional bias to cannabis words (cannabis Stroop task) and cannabis dependence. This study confirmed the relationship between cannabis dependence and attentional bias and extends this by highlighting a moderating role for cognitive control, which may make some more vulnerable to craving.

Marijuana: current concepts(†)

Marijuana (cannabis) remains a controversial drug in the twenty-first century. This paper considers current research on use of Cannabis sativa and its constituents such as the cannabinoids. Topics reviewed include prevalence of cannabis (pot) use, other drugs consumed with pot, the endocannabinoid system, use of medicinal marijuana, medical adverse effects of cannabis, and psychiatric adverse effects of cannabis use. Treatment of cannabis withdrawal and dependence is difficult and remains mainly based on psychological therapy; current research on pharmacologic management of problems related to cannabis consumption is also considered. The potential role of specific cannabinoids for medical benefit will be revealed as the twenty-first century matures. However, potential dangerous adverse effects from smoking marijuana are well known and should be clearly taught to a public that is often confused by a media-driven, though false message and promise of benign pot consumption.

Factors influencing mortality among alcohol and drug treatment clients in Victoria, Australia: the role of demographic and substance use characteristics

OBJECTIVE

Clinical studies consistently identify alcohol- and drug-related treatment populations as more likely to die prematurely compared with an age-matched general population. However, demographic characteristics and primary drug of concern as predictors of mortality risk following treatment have not been adequately explored. This paper examines relationships between substance use, demographic factors and mortality among alcohol and drug treatment clients.

METHOD

A retrospective cohort incorporating 7 years of data was utilised to examine mortality outcomes in the 2 years following treatment among Victorian clients recorded on the Alcohol and Drug Information Service (ADIS) database by linking partial client identifiers with the National Death Index (NDI). A cohort of 18,686 clients engaged in at least one course of treatment over a 12-month period was included. Analysis was of crude and standardised mortality rates across client groups in terms of the presenting drug of concern for treatment and demographic characteristics.

RESULTS

A higher risk of premature death was associated with older age, being male, not being employed, living alone, medical and psychiatric comorbidity, recent injecting, and a history of intensive drug treatment access. Alcohol treatment clients had the worst prognosis. After adjustment for client characteristics, alcohol treatment clients experienced a significantly higher rate of death compared with other clients.

CONCLUSIONS

Findings from these previously unexplored data highlight the need to increase awareness of the range and magnitude of risks associated with harmful alcohol use, and to identify approaches to enhance treatment effectiveness to reduce negative outcomes following treatment for populations at elevated risk of harm.