Sex Differences in the Association Between Cannabis Use and Suicidal Ideation and Attempts, Depression, and Psychological Distress Among Canadians

Trends in the co-occurrence of substance use and mental health symptomatology in a national sample of US post-secondary students from 2009 to 2019

Objective: This study examined joint trends over time in associations between substance use (heavy drinking, cannabis, and cigarette smoking) and mental health concerns (depression, anxiety, and suicidal ideation) among US post-secondary students. Participants: Data came from 323,896 students participating in the Healthy Minds Study from 2009 to 2019, a national cross-sectional survey of US post-secondary students. Weighted two-level logistic regression models with a time by substance interaction term were used to predict mental health status. Results: Use of each substance was associated with a greater odds of students endorsing depression, anxiety, and suicidal ideation. Over time, the association with mental health concerns strengthened substantially for cannabis, modestly for heavy drinking, and remained stable for smoking. Conclusion: Given co-occurrence is common and increasing among post-secondary students, college and university health systems should prioritize early identification, psychoeducation, harm-reduction, and brief interventions to support students at risk.

Examining temporal trends in psychological distress and the co-occurrence of common substance use in a population-based sample of grade 7-12 students from 2013 to 2019

PURPOSE

Characterizing trends and correlates of adolescent psychological distress is important due to observed global increases over the last 20 years. Substance use is a commonly discussed correlate, though we lack an understanding about how co-occurrence of these concerns has been changing over time.

METHODS

Data came from repeated, representative, cross-sectional surveys of grade 7-12 students across Ontario, Canada conducted biennially from 2013 to 2019. Poisson regression with robust standard errors was used to examine changes in the joint association between psychological distress (operationalized as Kessler-6 [K6] scores ≥ 13) and substance use over time. Weighted prevalence ratios (PR) and their 99% confidence intervals were estimated, where p < 0.01 denotes statistical significance.

RESULTS

The prevalence of psychological distress doubled between 2013 and 2019, with adjusted increases of about 1.2 times each survey year. This biennial increase did not differ based on sex, perceived social standing, school level, or any substance use. Students using substances consistently reported a higher prevalence of psychological distress (between 1.2 times and 2.7 times higher). There were similarly no differential temporal trends based on substance use for very high distress (K6 ≥ 19) or K6 items explored individually.

CONCLUSION

Psychological distress steeply increased among adolescents and substance use remains important to assess and address alongside distress. However, the magnitude of temporal increases appears to be similar for adolescents reporting and not reporting substance use.

Associations between cannabis use, opioid misuse and severe psychological distress in adolescents: A cross-sectional school-based study

BACKGROUND

Cannabis use and nonmedical use of prescription opioids are consumed by a small to moderate number of adolescents. However, little is known about their combined influence on mental health in this age group. This study examined the association between cannabis use, nonmedical use of prescription opioids, or both with serious psychological distress among adolescents and tested if sex could moderate these associations.

METHODS

We based our analyses on cross-sectional data from the 2019 Ontario Student Drug Use and Health Survey, a provincially representative sample of students in grades 7 through 12 (aged 11-20 years or older) across Ontario, Canada (n= 7097; mean age: 15.2 ± 1.2 years). Logistic regression analyses were adjusted for important covariates.

RESULTS

We found that 20.5% reported cannabis use only, 5.8% reported opioid use only, and 5% reported both cannabis and opioid use. Cannabis use only (odds ratio [OR]:1.91; 95% confidence interval [CI]:1.53-2.37), opioid use only (OR: 2.21; 95% CI: 1.63-3.00), and both cannabis and opioid use (OR: 3.24; 95% CI: 2.25-4.66) were associated with greater odds of serious psychological distress after adjustment for covariates. Associations were similar for males and females.

CONCLUSION

The use of both cannabis and opioids is significantly associated with serious psychological distress among adolescents. Adolescents who use both cannabis and opioids represent a small and vulnerable group that should be targeted in future interventions against mental health problems. Health professionals should consider screening for polysubstance use, especially when working with adolescents who use cannabis.

Unhealthy behaviors associated with mental health disorders: a systematic comparative review of diet quality, sedentary behavior, and cannabis and tobacco use

Background

There are well-established literatures documenting the associations between mental disorders and unhealthy behaviors such as poor diet quality, sedentary behavior, and cannabis and tobacco use. Few studies have attempted to understand the respective findings in light of each other, however.

Objective

The purpose of this review was to assemble comparable data for each behavior-disorder association and assess the associations in terms of their overall strength. The review aimed to include a representative, but not exhaustive, range of studies that would allow for explorative comparisons.

Methods

Eligible studies were identified via Pubmed searches and citation searching, restricted to publications no older than 2015 written in English. To obtain comparable data, only studies that reported findings as odds ratios were included, and risk of bias related to study samples, behavioral measurement disparities, and control variables was assessed via sensitivity analyses. Findings for each disorder were compared on the basis of different measures of central tendency.

Results

From 3,682 records, 294 studies were included. The review found evidence of associations between each of the four unhealthy behaviors and psychosis, depression, anxiety, bipolar disorder, attention-deficit/hyperactivity disorder (ADHD), and post-traumatic stress disorder (PTSD), while personality disorder was only investigated in relation to cannabis and tobacco use. In overall comparison, the associations were generally of similar strength, and only the association between cannabis use and personality disorder was exceptional in terms of being significantly stronger than its counterparts across disorders and across behaviors. Analyses of bias risk identified some influence from behavioral measurement disparities and lack of adequate statistical control, but findings were generally robust across a range of sensitivity analyses.

Conclusion

This explorative and comparative review found that poor diet quality, sedentary behavior, and cannabis and tobacco use are about equally strongly associated with a range of different mental disorders. Given the general nature of these associations, we should probably understand them to reflect a general and shared etiology. However, the findings in this review should be regarded as tentative until confirmed by more comprehensive investigations.

The Effect of Cannabis Use on Depression

This article presents the case of a 21-year-old female with a psychiatric history of depression and a history of chronic cannabis use who presented to the emergency department after overdosing on ondansetron and was urine test positive for marijuana (tetrahydrocannabinol (THC)). The patient was later transferred to a psychiatric unit for further evaluation, and after six days of hospitalization and cessation of marijuana, the patient demonstrated gradual improvement in her mental status examination and was deemed fit for discharge with follow-up instructions. This case illustrates the effect of cannabis use and cannabis use disorder on those with major depressive disorder (MDD), the component of cannabis that worsens the symptoms of depression, the role of the endocannabinoid system (ECS) in depression, and available treatments.

The relationship between depressed affect, parental monitoring, and sex on cannabis use among American Indian youth

BACKGROUND AND OBJECTIVES

American Indian (AI) adolescents report higher rates of cannabis use than national US adolescents. Previous study examined interactive relationships between depressed affect and family factors on AI adolescent alcohol use. These factors have not been investigated for cannabis use. We examined whether parental monitoring dampened risk for cannabis use due to depressed affect, and potential moderation by sex.

METHODS

We measured cannabis use, depressed affect, parental monitoring, and sex among reservation area AI youth among students in grades 7-12 attending 45 schools. We used censor-inflated regression models to identify parental monitoring as a moderator of the relationship between depressed affect and cannabis use.

RESULTS

In the logistic portion of censor-inflated models, level of depressed affect and parental monitoring significantly related to last 30-day cannabis use. Higher levels of parental monitoring at lower levels of depressed affect related to lower likelihood of cannabis use. Female students had greater likelihood of endorsing cannabis use at higher levels of depressed affect. In the linear portion of the censor-inflated regression models, sex and level of parental monitoring significantly related to cannabis use frequency. Male students endorsed more frequent cannabis use while higher levels of parental monitoring related to lower frequency of use.

DISCUSSION AND CONCLUSIONS

Parental monitoring may dampen the effect of depressed affect on cannabis use among AI youth on reservations.

SCIENTIFIC SIGNIFICANCE

Future interventions should foster skill-building prevention efforts directed at coping with depression, along with parental training for effective monitoring. Special attention to AI female adolescents may be indicated.

Emotion dysregulation in relation to cannabis use and mental health among young adults

BACKGROUND

Emotion dysregulation (ED) is a transdiagnostic variable that accounts for the onset and maintenance of mental health disorders. The interplay between ED, cannabis use and mental health has not been appraised in the young adult population and whether there are sex-dependent effects has yet to be examined. This study looked at whether ED mediates the association between past-month cannabis use and mental health, while considering sex as a moderator.

METHODS

2,762 (64.2% women) undergraduate Spanish students completed an online battery. Among others, they fulfilled the Depression Anxiety Stress Scale-21 (DASS-21) and the Difficulties in Emotion Regulation Scale (DERS-28). A two-way ANOVA assessed the effects of sex and past-month cannabis use on participants' DASS-21 scores. A set of moderated mediations tested whether the indirect effect of past-month cannabis use on DASS-21 through DERS differed by sex.

RESULTS

Past-month cannabis female users showed higher levels of depression, anxiety and stress (M = 51.10, SD = 26.72) than did men [(M = 33.76, SD = 20.31); F(1, 2758) = 5.119, p =.024, η²p =.002]. In female young adults only, the effect of past-month cannabis use on mental health was mediated by ED (total score), non-acceptance of emotional responses, lack of emotional control, difficulties in engaging in goal-directed behavior, and lack of emotional clarity (all p's < 0.005) CONCLUSIONS: Findings indicate the importance of considering ED in assessment and intervention practices. Interventions targeting ED may be particularly effective for female young adult cannabis users.

Canadian Network for Mood and Anxiety Treatments (CANMAT) Task Force Report: A Systematic Review and Recommendations of Cannabis use in Bipolar Disorder and Major Depressive Disorder

BACKGROUND

Given the increasing acceptability and legalization of cannabis in some jurisdictions, clinicians need to improve their understanding of the effect of cannabis use on mood disorders.

OBJECTIVE

The purpose of this task force report is to examine the association between cannabis use and incidence, presentation, course and treatment of bipolar disorder and major depressive disorder, and the treatment of comorbid cannabis use disorder.

METHODS

We conducted a systematic literature review using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, searching PubMed, Embase, PsycINFO, CINAHL and Cochrane Central Register of Controlled Trials from inception to October 2020 focusing on cannabis use and bipolar disorder or major depressive disorder, and treatment of comorbid cannabis use disorder. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach was used to evaluate the quality of evidence and clinical considerations were integrated to generate Canadian Network for Mood and Anxiety Treatments recommendations.

RESULTS

Of 12,691 publications, 56 met the criteria: 23 on bipolar disorder, 21 on major depressive disorder, 11 on both diagnoses and 1 on treatment of comorbid cannabis use disorder and major depressive disorder. Of 2,479,640 participants, 12,502 were comparison participants, 73,891 had bipolar disorder and 408,223 major depressive disorder without cannabis use. Of those with cannabis use, 2,761 had bipolar disorder and 5,044 major depressive disorder. The lifetime prevalence of cannabis use was 52%-71% and 6%-50% in bipolar disorder and major depressive disorder, respectively. Cannabis use was associated with worsening course and symptoms of both mood disorders, with more consistent associations in bipolar disorder than major depressive disorder: increased severity of depressive, manic and psychotic symptoms in bipolar disorder and depressive symptoms in major depressive disorder. Cannabis use was associated with increased suicidality and decreased functioning in both bipolar disorder and major depressive disorder. Treatment of comorbid cannabis use disorder and major depressive disorder did not show significant results.

CONCLUSION

The data indicate that cannabis use is associated with worsened course and functioning of bipolar disorder and major depressive disorder. Future studies should include more accurate determinations of type, amount and frequency of cannabis use and select comparison groups which allow to control for underlying common factors.

Impacts of recreational cannabis legalization on use and harms: A narrative review of sex/gender differences

Legalization of cannabis use for non-medical (recreational) purposes is changing the global cannabis landscape. As attitudes toward cannabis use become more positive and prevalence of use increases in complex ways, concerns emerge about the potential for increased cannabis-attributable harms. Understanding the who, why, and when of this likely increase in cannabis-attributable harms is thus an important public health priority. Both sex and gender contribute to variability in the use, effects, and harms of cannabis and thus sex/gender considerations are important when evaluating the impacts of cannabis legalization. The goal of this narrative review is to broadly discuss sex/gender differences in attitudes toward and prevalence of cannabis use, whether there are sex/gender differences in the impacts of cannabis legalization, and why these sex/gender differences might exist. One of our strongest conclusions is that men have always been more likely to use cannabis than women, yet the sex/gender gap in prevalence of cannabis use has narrowed over time, and this might be partly due to cannabis legalization. The existing evidence suggests that there have also been sex/gender differences in the impacts of legalization on cannabis-attributable harms such as cannabis-involved motor vehicle collisions and hospitalizations, though these results are more variable. The body of literature reviewed has focused almost exclusively on samples of cisgender research participants, and thus future research should encourage inclusion of transgender and gender-diverse participants. More consideration of sex- and gender-based analysis in research evaluating long-term impacts of cannabis legalization is a clear research priority.

Prevalence and variables associated with depression, anxiety, and stress among Chilean higher education students, post-pandemic

Background

Mental health among university students is a public health problem in Chile, understanding that this population is susceptible to mental disorders.

Objective

The present study aimed to determine the prevalence and variables influencing depression, anxiety, and stress in Chilean university students.

Method

A representative sample (n = 1,062) of Chilean university students and a cross-sectional study design were used. Bivariate analysis and multiple logistic regression were performed to identify risk factors associated with symptomatology. They were analyzed using descriptive statistics. A questionnaire with sociodemographic variables was applied in November 2022, in addition to the depression anxiety stress scale (DASS-21), instruments with excellent reliability in this population (α = 0.955; ω = 0.956). On the other hand, the Questionnaire of Problematic Alcohol and Drug Consumption (DEP-ADO) was applied. A descriptive analysis was performed, followed by bivariate analysis and multiple logistic regression using SPSS version 25. The variables showed a value of p <0.05; they were declared statistically significant in the final model. Odds ratios (OR) were adjusted to a 95% confidence interval (95% CI), which was used to determine the independent predictors.

Results

The prevalence of mental health problems in this population was high, with depressive symptoms in 63.1% of the sample; 69.2% with anxiety; 57% with stress; 27.4% with problematic alcohol consumption; and 14.9% with inappropriate marijuana consumption. Some 10.1% of the sample reported daily medication with antidepressants and/or anxiolytics. Concerning significant variables for depression, these were: being female, belonging to sexual, not having children, having problematic marijuana use, and using prescription drugs. Concerning anxiety, the significant variables were being a woman, belonging to sexual minorities, being an adolescent, and consuming prescription medication. Finally, concerning stress, the significant variables were being a woman, belonging to sexual minorities, being a student dedicated exclusively to academic activities, and taking prescription medication.

Conclusion

Chilean university students presented a high prevalence of anxiety, depression, and stress, where being female and belonging to sexual minorities seem to be the variables that have the greatest impact on susceptibility to mental health problems. These results should call the attention of political and university authorities in Chile to improve this population's mental health and quality of life since they are the following professional generation of our country.

Suicidal ideation among Canadian adults during the COVID-19 pandemic: the role of psychosocial factors and substance use behaviours

BACKGROUND

Suicide is one of the most important and increasing public health agenda around the world. Since the COVID-19 pandemic, concerns have been raised about the potential adverse impacts of the pandemic on suicide-related outcomes. The main objective of this study was to examine the association of psychosocial risk factors (mental health illnesses and social isolation) and substance use behaviors (cannabis and alcohol consumption) with suicidal ideation during the COVID-19 pandemic among Canadian adults.

METHODS

The study was conducted based on a total of 4005 persons 18 years of age or older, living in Canada's ten provinces. The data used in this study were collected during April 20-28, 2021, by Mental Health Research Canada. Multivariable logistic regression was used to determine the association of mental health conditions (anxiety, depression, and other mood disorder) before and since COVID-19 outbreaks, social isolation and living arrangement, as well as cannabis and alcohol consumption with suicidal ideation during COVID-19.

RESULTS

The results of adjusted logistic regression showed that the odds of suicidal ideation were 1.526 times higher (95% CI:1.082-2.152) among those who reported continued negative impacts of social isolation. The odds of suicidal ideation were also higher for those who were diagnosed as having depression before (OR = 3.136, 95% CI: 2.376-4.138) and since the COVID-19 pandemic (OR = 3.019, 95% CI:1.929-4.726) and 1.627 times higher (95% CI: 1.225-2.163) for those who were diagnosed as having anxiety before the COVID-19 pandemic. Those who reported having increased and those who were consuming cannabis during the pandemic were 1.970 (95% CI: 1.463-2.653) and 1.509 times (95% CI: 1.158-1.966) more likely to have thought of suicide than non-takers, respectively.

CONCLUSION

Given the significant associations of psychosocial factors (mental health illnesses and social isolation) and cannabis use with suicidal ideation, more attention and support need to be given to adults who had mental health conditions before and since COVID-19, those who were negatively impacted by social isolation, and those are exposed to substance use (cannabis).

Generalized Anxiety Disorder 7-Item (GAD-7) Scores in Medically Authorized Cannabis Patients-Ontario and Alberta, Canada

OBJECTIVES

Despite increasing rates of legalization of medical cannabis worldwide, the current evidence available on its effect on mental health outcomes including anxiety is of mixed results. This study assesses the effect of medical cannabis on generalized anxiety disorder 7-item (GAD-7) scores in adult patients between 2014 and 2019 in Ontario and Alberta, Canada.

METHODS

An observational cohort study of adults authorized to use medical cannabis. The GAD-7 was administered at the time of the first visit to the clinic and subsequently over the follow-up time period of up to 3.2 years. Overall changes in GAD-7 scores were computed (mean change) and categorized as: no change (<1 point); improvement; or worsening-over time.

RESULTS

A total of 37,303 patients had initial GAD-7 scores recorded and 5,075 (13.6%) patients had subsequent GAD-7 follow-up scores. The average age was 54.2 years (SD 15.7 years), 46.0% were male, and 45.6% noted anxiety symptoms at the baseline. Average GAD-7 scores were 9.11 (SD 6.6) at the baseline and after an average of 282 days of follow-up (SD 264) the average final GAD-7 score recorded was 9.04 (SD 6.6): mean change -0.23 (95% CI, -0.28 to -0.17, t[5,074]: -8.19, p-value <0.001). A total of 4,607 patients (90.8%) had no change in GAD-7 score from their initial to final follow-up, 188 (3.7%) had a clinically significant decrease, and 64 (1.3%) noted a clinically significant increase in their GAD-7 scores.

CONCLUSIONS

Overall, there was a statistically significant decrease in GAD-7 scores over time (in particular, in the 6-12-month period). However, this change did not meet the threshold to be considered clinically significant. Thus, we did not detect clinical improvements or detriment in GAD-7 scores in medically authorized cannabis patients. However, future well-controlled clinical trials are needed to fully examine risks or benefits associated with using medical cannabis to treat anxiety conditions.

Gender Differences in Dual Diagnoses Associated with Cannabis Use: A Review

Gender differences in psychiatric disorders and drug use are well known. Cannabis is the most widely used illegal drug among young people. In recent years, its use has been related to the development of psychiatric pathologies; however, few studies have incorporated the gender perspective as of yet. The present work analyses the literature to determine the existence of gender differences in the development of psychotic, depressive and anxious symptoms associated with cannabis use. First, we describe cannabis misuse and its consequences, paying special attention to adolescent subjects. Second, the main gender differences in psychiatric disorders, such as psychosis, depression, anxiety and cannabis use disorders, are enumerated. Subsequently, we discuss the studies that have evaluated gender differences in the association between cannabis use and the appearance of psychotic, depressive and anxious symptoms; moreover, we consider the possible explanations for the identified gender differences. In conclusion, the studies referred to in this review reveal the existence of gender differences in psychiatric symptoms associated with cannabis use, although the direction of such differences is not always clear. Future research is necessary to discern the causal relationship between cannabis use and the development of psychiatric symptoms, as well as the gender differences found.

Associations between Recent and Cumulative Cannabis Use and Internalizing Problems in Boys from Adolescence to Young Adulthood

This study tested whether increases in recent and cumulative cannabis use were each associated with increases in internalizing problems from adolescence to young adulthood. Participants were boys from a community sample that was assessed annually from ~age 15-26 (N = 506). Boys reported on their cannabis use, depression symptoms, and anxiety/depression problems each year. Exposures were frequency of cannabis use in a given year (no use, < weekly use, weekly or more frequent use) and cumulative prior years of weekly cannabis use. Outcomes were depression symptoms and anxiety/depression problems in a given year. Analyses examined within-person associations between changes in exposures and outcomes over time, which eliminated "fixed" (unchanging) individual differences as potential confounds. Analyses also accounted for time-varying factors as potential confounds (other substance use, externalizing problems, subclinical psychotic symptoms). Results showed that increases in recent cannabis use and cumulative prior years of weekly cannabis use were each associated with increases in depression symptoms and anxiety/depression problems. After controlling for time-varying covariates, increases in cumulative prior years of weekly cannabis use, but not recent cannabis use, remained associated with increases in depression symptoms and anxiety/depression problems. Specifically, each additional year of prior weekly cannabis use was associated with a small increase in depression symptoms (b = 0.012, p = .005) and anxiety/depression problems (b = 0.009, p = .001). Associations did not vary systematically across time. There was also no evidence of reverse causation. As boys engaged in weekly cannabis use for more years, they showed increases in internalizing problems, suggesting the importance of preventing chronic weekly cannabis use.

Marijuana use and suicidal behaviours among school-going adolescents in Africa: assessments of prevalence and risk factors from the Global School-Based Student Health Survey

Background

Marijuana use among adolescents, including high school students, has been consistently reported to be associated with a high incidence of suicidal behaviours. Little empirical research has been conducted on the propensity impact of marijuana use on suicidal behaviours in Africa.

Aims

To assess factors associated with marijuana use and further quantify marijuana use as an associated factor of suicidal behaviours, including repeated attempted suicide, suicidal ideation and suicide planning, among high school students in Africa.

Methods

A cross-sectional study was conducted among 32 802 school-going adolescents using the Global School-Based Student Health Survey data from 10 African countries grouped into West Africa, North Africa, South-East Africa, South Africa and East Africa subregions. Marijuana use and repeated attempted suicide were the main outcome variables. We employed double selection least absolute shrinkage and selection operator poisson regression model to assess risk factors associated with marijuana use and dominance analysis to establish ranked important and common risk factors. Inverse probability weighting poisson regression adjustment was applied to assess impact.

Results

The prevalence of marijuana use and repeated attempted suicide were 3.7% (95% CI: 3.1 to 4.3) and 6.6% (95% CI: 5.9 to 7.4), respectively. The most important risk factor for marijuana use generally across the countries and specifically in three subregions was alcohol consumption, which constituted approximately 40% of the impact. The average treatment effect on the treated (ATT) indicated that marijuana use significantly increased the risk of suicidal ideation, suicide planning and repeated attempted suicide by 12% (ATT=0.12 (95% CI: 0.02 to 0.22)), 18% (ATT=0.18 (95% CI: 0.13 to 0.22)) and 31% (ATT=0.31 (95% CI: 0.20 to 0.41)), respectively.

Conclusions

Marijuana use was significantly associated with suicidal behaviours (suicidal ideation, planning and repeated attempted suicide) among the students. To achieve Sustainable Development Goal 3.5 (to strengthen prevention and treatment of substance abuse), school-based psychosocial interventions should be streamlined to adequately assess and manage marijuana use. Targeting the most dominant risk factors in this population could translate into the reduction of suicidal behaviours in countries within Africa.

Down and High: Reflections Regarding Depression and Cannabis

In light of the recent changes in the legal status of cannabis in Canada, the understanding of the potential impact of the use of cannabis by individuals suffering from depression is increasingly considered as being important. It is fundamental that we look into the existing literature to examine the influence of cannabis on psychiatric conditions, including mood disorders. In this article, we will explore the relationship that exists between depression and cannabis. We will examine the impact of cannabis on the onset and course of depression, and its treatment. We have undertaken a wide-ranging review of the literature in order to address these questions. The evidence from longitudinal studies suggest that there is a bidirectional relationship between cannabis use and depression, such that cannabis use increases the risk for depression and vice-versa. This risk is possibly higher in heavy users having initiated their consumption in early adolescence. Clinical evidence also suggests that cannabis use is associated with a worse prognosis in individuals with major depressive disorder. The link with suicide remains controversial. Moreover, there is insufficient data to determine the impact of cannabis use on cognition in individuals with major depression disorder. Preliminary evidence suggesting that the endogenous cannabinoid system is involved in the pathophysiology of depression. This will need to be confirmed in future positron emission tomography studies. Randomized controlled trials are needed to investigate the potential efficacy of motivational interviewing and/or cognitive behavioral therapy for the treatment of cannabis use disorder in individuals with major depressive major disorder. Finally, although there is preclinical evidence suggesting that cannabidiol has antidepressant properties, randomized controlled trials will need to properly investigate this possibility in humans.

Sex and dependence related neuroanatomical differences in regular cannabis users: findings from the ENIGMA Addiction Working Group

Males and females show different patterns of cannabis use and related psychosocial outcomes. However, the neuroanatomical substrates underlying such differences are poorly understood. The aim of this study was to map sex differences in the neurobiology (as indexed by brain volumes) of dependent and recreational cannabis use. We compared the volume of a priori regions of interest (i.e., amygdala, hippocampus, nucleus accumbens, insula, orbitofrontal cortex (OFC), anterior cingulate cortex and cerebellum) between 129 regular cannabis users (of whom 70 were recreational users and 59 cannabis dependent) and 114 controls recruited from the ENIGMA Addiction Working Group, accounting for intracranial volume, age, IQ, and alcohol and tobacco use. Dependent cannabis users, particularly females, had (marginally significant) smaller volumes of the lateral OFC and cerebellar white matter than recreational users and controls. In dependent (but not recreational) cannabis users, there was a significant association between female sex and smaller volumes of the cerebellar white matter and OFC. Volume of the OFC was also predicted by monthly standard drinks. No significant effects emerged the other brain regions of interest. Our findings warrant future multimodal studies that examine if sex and cannabis dependence are specific key drivers of neurobiological alterations in cannabis users. This, in turn, could help to identify neural pathways specifically involved in vulnerable cannabis users (e.g., females with cannabis dependence) and inform individually tailored neurobiological targets for treatment.

Patterns of substance use among adolescents: A systematic review

PURPOSE

This review characterizes empirically derived patterns of multiple (multi-) substance use among adolescents. A secondary objective was to examine the extent to which mental health symptomatology was included in the empirical analyses examining substance use patterns.

METHODS

Eligible studies included those that used cluster-based approaches, included the assessment of at least two different substances, and were based on study samples with mean ages between 11 and 18 years. 4665 records were screened including 461 studies for full-text screening.

RESULTS

70 studies were included with common clusters being: low use, single or dual substance use, moderate general multi-use, and high multi-use. The most common patterns of single or multi-substance use were: alcohol only, alcohol with cannabis and/or tobacco, and use of alcohol, tobacco, and cannabis with and without other drugs. Lower socioeconomic status, older age, and male gender were consistent predictors of multi-use clusters. Only 37 % of studies compared differences in levels of mental health across clusters with symptoms consistently associated with a greater likelihood of multi-use. Only 29 % of studies included mental health indicators in cluster-based analyses, with over half identifying distinct mental health and substance use clusters. Fit indices in cluster analyses and measurement properties of substance use were heterogeneous and inconsistently reported across studies.

CONCLUSIONS

Distinct patterns of substance use were derived but methodological differences prevented direct comparison and reduced capacity to generalize across studies. There is a need to establish standardized methodological approaches to identify robust patterns of substance use to enhance etiological, prognostic, and intervention research.

Cannabis use, depression and suicidal ideation in adolescence: direction of associations in a population based cohort

BACKGROUND

To clarify the direction of the association between frequency of cannabis use, depressive symptoms and suicidal ideation from 15 to 20 years using cross-lagged analyses.

METHOD

We included 1606 adolescents from the province of Québec followed since 1997 with information on frequency of cannabis use (none/monthly/weekly), depression (defined as being in the top 10% symptoms) and serious suicidal ideation at ages 15, 17 and 20 years.

RESULTS

The prevalence of weekly cannabis use increased from 7.0% at age 15 years to 15.6% by age 20 years. Adolescents who reported using cannabis weekly at one age were 11 to 15 times more likely to continue using cannabis over time. In longitudinal cross-lagged analyses, weekly cannabis use at age 15 was associated with greater odds (OR=2.19, 95% CI=1.04-4.58) of suicidal ideation two years later. However, other substance use (alcohol, tobacco, other drugs) fully explained this association. Further, depression predicted subsequent weekly cannabis use, even after adjusting for comorbid other substance use (eg, for depression at 15 years predicting cannabis use at 17 years: OR=2.30, 95% CI=1.19-4.43).

LIMITATIONS

Quantity of cannabis consumed was not measured.

CONCLUSION

Findings suggest that depressive symptoms in adolescence may represent a risk factor for weekly cannabis consumption, which once initiated is likely to remain chronic. Weekly cannabis use increased risk for suicidal ideation, but not independently from other substance use including alcohol, tobacco and other drugs.

Changes in patient health questionnaire (PHQ-9) scores in adults with medical authorization for cannabis

Background

Legal access to medical cannabis is increasing world-wide. Despite this, there is a lack of evidence surrounding its efficacy on mental health outcomes, particularly, on depression. This study assesses the effect of medical cannabis on Patient Health Questionnaire (PHQ-9) scores in adult patients between 2014 and 2019 in Ontario and Alberta, Canada.

Methods

An observational cohort study of medically authorized cannabis patients in Ontario and Alberta. Overall change in PHQ-9 scores from baseline to follow-up were evaluated (mean change) over a time period of up to 3.2 years.

Results

37,338 patients from the cohort had an initial PHQ-9 score recorded with 5103 (13.7%) patients having follow-up PHQ-9 scores. The average age was 54 yrs. (SD 15.7), 46% male, 50% noted depression at baseline. The average PHQ-9 score at baseline was 10.5 (SD 6.9), following a median follow-up time of 196 days (IQR: 77–451) the average final PHQ-9 score was 10.3 (SD 6.8) with a mean change of − 0.20 (95% CI: − 0.26, − 0.14, p-value < 0.0001). Overall, 4855 (95.1%) had no clinically significant change in their PHQ-9 score following medical cannabis use while 172 (3.4%) reported improvement and 76 (1.5%) reported worsening of their depression symptoms.

Conclusions

Although the majority showed no clinically important changes in PHQ-9 scores, a number of patients showed improvement or deteriorations in PHQ-9 scores. Future studies should focus on the parallel use of screening questionnaires to control for PHQ-9 sensitivity and to explore potential factors that may have attributed to the improvement in scores pre- and post- 3-6 month time period.

Sex differences in the interactive effects of early life stress and the endocannabinoid system

Sex differences in both the endocannabinoid system and stress responses have been established for decades. While there is ample evidence that the sexes respond differently to stress and that the endocannabinoid system is involved in this response, what is less clear is whether the endocannabinoid system mediates this response to stress differently in both sexes. Also, do the sexes respond similarly to exogenous cannabinoids (CBs) following stress? Can the administration of exogenous CBs normalize the effects of stress and if so, does this happen similarly in male and female subjects? This review will attempt to delineate the stress induced neurochemical alterations in the endocannabinoid system and the resulting behavioral changes across periods of development: prenatal, early neonatal or adolescent in males and females. Within this frame work, we will then examine the neurochemical and behavioral effects of exogenous CBs and illustrate that the response to CBs is determined by the stress history of the animal. The theoretical framework for this endeavor relates to the established effects of adverse childhood experiences (ACE) in increasing substance abuse, depression and anxiety and the possibility that individuals with high ACE scores may consume cannabinoids to "self-medicate". Overall, we see that while there are instances where exogenous cannabinoids "normalize" the adverse effects produced by early stress, this normalization does not occur in all animal models with any sort of consistency. The most compelling report where CB administration appears to normalize behaviors altered by early stress, shows minimal differences between the sexes (Alteba et al., 2016). This is in stark contrast to the majority of studies on early stress and the endocannabinoid system where both sexes are included and show quite divergent, in fact opposite, effects in males and females. Frequently there is a disconnect between neurochemical changes and behavioral changes and often, exogenous CBs have greater effects in stressed animals compared to non-stressed controls. This report as well as others reviewed here do support the concept that the effects of exogenous CBs are different in individuals experiencing early stress and that these differences are not equal in males and females. However, due to the wide variety of stressors used and the range of ages when the stress is applied, additional careful studies are warranted to fully understand the interactive effects of stress and the endocannabinoid system in males and females. In general, the findings do not support the statement that CB self-administration is an effective treatment for the adverse behavioral effects of early maltreatment in either males or females. Certainly this review should draw the attention of clinicians working with children, adolescents and adults exposed to early trauma and provide some perspective on the dysregulation of the endocannabinoid system in the response to trauma, the complex actions of exogenous CBs based on stress history and the unique effects of these factors in men and women.

Temporal Changes in the Cross-Sectional Associations between Cannabis Use, Suicidal Ideation, and Depression in a Nationally Representative Sample of Canadian Adults in 2012 Compared to 2002

BACKGROUND

With the recent legalization of nonmedical cannabis in Canada, it is important to document previous associations between cannabis use and major depressive episode and suicidal ideation, as well as the extent to which these associations have changed over time.

METHODS

This study uses pooled data from the 2002 and 2012 Canadian Community Health Survey's Mental Health Component, which are repeated cross-sectional surveys of nationally representative samples of Canadians 15 to 60 years of age (n = 43,466). Binary logistic regression was performed, applying weighting and bootstrapping, to examine the association between at least monthly use of cannabis and past 12-month suicidal ideation and major depressive episode (MDE).

RESULTS

At least monthly nonmedical cannabis use was associated with an increased odds of MDE and suicidal ideation, and both associations strengthened in 2012 compared to 2002. Canadians using cannabis at least once a month in 2012 had 1.59 (95% confidence interval [CI], 1.11 to 2.27) times the odds of experiencing suicidal ideation and 1.55 (95% CI, 1.12 to 2.13) times the odds of experiencing MDE compared to those who used cannabis at least once a month in 2002. This temporal change remained after controlling for other substance use.

CONCLUSIONS

Monthly cannabis use was consistently related to both suicidal ideation and MDE, and these associations were stronger in 2012 compared to 2002. The findings of this study provide a baseline for the association between cannabis use and suicide and depression in the Canadian population that should be reevaluated now that nonmedical cannabis has been legalized.

Suicide among people treated for drug use disorders: a Danish national record-linkage study

Background

Substance use disorders are a major risk factor for suicide. However, less is known about specific risk factors for suicide in people with substance use disorders.

Methods

This population cohort study assessed suicide among people treated for drug use disorders in Denmark 2000–2010, and described risk factors for completed suicide. Data from 27,942 individuals enrolled in treatment were linked to national registers and matched with controls without drug use disorder and with (n = 138,136) or without psychiatric history (n = 1574). Competing risk regression was used to identify risk factors of completed suicide.

Results

There were 163 suicides among patients with a history of drug treatment (0.6% of patients). Increased risk was associated with younger age at enrolment (hazard ratio [HR] = 0.97, 95% confidence interval (CI): 0.95, 0.98), history of psychiatric care (HR = 1.96, CI 95%: 1.39, 2.77), opioid use (HR = 1.81, 95% CI: 1.23, 2.68), and alcohol use (HR = 1.56, 95% CI: 1.09, 2.23). Lower risk was associated with cannabis use (HR = 0.69, 95% CI: 0.50, 0.96). Compared with age- and gender-matched controls without a history of treatment for substance use disorders or recent psychiatric care, the standardized mortality ratio due to suicide was 7.13 for people with drug use disorder without a history of psychiatric care (95% CI: 5.81, 8.44), 13.48 for people with drug use disorder and psychiatric history (95% CI: 9.75, 17.22), and 13.61 for people with psychiatric history only (95% CI: 6.72, 20.50).

Conclusions

Risk of suicide is increased among people with drug use disorders. Access to treatment for co-morbid mental health problems for people with drug use disorders could potentially reduce risk of suicide.