Adolescent cannabis use and risk of mental health problems-the need for newer data

Youth cannabis use and subsequent health service use for mood and anxiety disorders: A population-based cohort study

Epidemiologic research suggests a modest association between youth cannabis use and mood and anxiety disorders (MADs). However, current evidence is based mostly on cohort studies using data from the 20th century when cannabis was significantly less potent than today. We linked population-based survey data from 2009 to 2012 with administrative records of health services covered under universal healthcare up to 2017. The cohort included youth aged 12 to 24 years at baseline living in Ontario, Canada with no prior MAD health service use (n = 8,252). We conducted a multivariable Cox model to estimate the association between cannabis use frequency (never, Collapse

Key Words

• Anxiety disorders
• Cannabis
• Mood disorders
• Psychiatry
• Youth

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MESH Headings

• Humans
• Adolescent
• Anxiety Disorders/epidemiology
• Anxiety Disorders/therapy
• Cannabis
• Cohort Studies
• Ontario/epidemiology
• Hospitalization
• Patient Acceptance of Health Care

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Affiliation(s)

André J McDonald Epidemiology Division, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada; Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Peter Boris Centre for Addictions Research, St. Joseph's Healthcare Hamilton, Hamilton, Ontario, Canada; Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada; Michael G. DeGroote Centre for Medicinal Cannabis Research, McMaster University, Hamilton, Ontario, Canada.
Paul Kurdyak Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada; ICES, Toronto, Ontario, Canada; Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
Jürgen Rehm Epidemiology Division, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada; Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Institute of Clinical Psychology and Psychotherapy, Technische Universität Dresden, Dresden, Germany; Department of Psychiatry and Psychotherapy, Centre for Interdisciplinary Addiction Research (ZIS), University Medical Centre Hamburg-Eppendorf, Hamburg, Germany; Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation
Michael Roerecke Epidemiology Division, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada; Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
Susan J Bondy Epidemiology Division, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada

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Association between Cannabis Use Disorder and Mental Health Disorders in the Adolescent Population: A Cohort Study

INTRODUCTION

According to the literature, early initiation to cannabis use and a dependent pattern of use are important risk factors for the development of mental health disorders. However, there are few cohort studies which look at the development of mental health disorders associated with cannabis use among young people with cannabis use disorder (CUD). The aim of the study was to determine the cumulative incidence of mental health disorders and the risk of developing mental health disorders among minors who commenced treatment for CUD in Catalonia during 2015-2019.

METHODS

This was a retrospective fixed cohort study, matched for confounding variables, based on data from the Catalan Health Surveillance System. The exposed cohort comprised young people who entered treatment for CUD during 2015-2019 (n = 948) and who were minors on the date of commencing treatment. Matching was done with a paired cohort (n = 4,737), according to confounding variables. Individuals with a diagnosis of a mental health disorder prior to the study period were excluded. The cumulative incidence was calculated for mental health disorders for the exposed and the paired cohorts and stratified by type of mental disorder. Incidence rate ratios were estimated using the conditional Poisson model with robust variance, stratified by sex.

RESULTS

The cumulative incidence for development of a mental health disorder was 19.6% in the exposed cohort and 3.1% in the paired cohort; with higher incidence among females (females 32.7%; males 15.8%). The exposed cohort had an 8.7 times increased risk of developing a mental health disorder than the paired cohort. The most frequent diagnoses were reaction to severe stress, adjustment disorder, and personality disorders.

CONCLUSION

This study confirmed that the exposed cohort was at increased risk of developing mental health disorders compared to the paired cohort. To date, few studies have analyzed the association between cannabis use and the development of mental health disorders, considering cannabis dependence. Further studies should be undertaken considering CUD. In addition, more studies are needed to understand the factors that determine the development of CUD. Further research in these areas would contribute to the design of prevention strategies aimed at those young individuals with a higher risk of developing cannabis dependence and suffering its consequences.

Serum lipid analysis and isotopic enrichment is suggestive of greater lipogenesis in young long-term cannabis users: A secondary analysis of a case-control study

Cannabis is now legal in many countries and while numerous studies have reported on its impact on cognition and appetite regulation, none have examined fatty acid metabolism in young cannabis users. We conducted an exploratory analysis to evaluate cannabis impact on fatty acid metabolism in cannabis users (n = 21) and non-cannabis users (n = 16). Serum levels of some saturated and monounsaturated fatty acids, including palmitic, palmitoleic, and oleic acids were higher in cannabis users compared to nonusers. As palmitic acid can be derived from diet or lipogenesis from sugars, we evaluated lipogenesis using a de novo lipogenesis index (palmitate/linoleic acid) and carbon-specific isotope analysis, which allows for the determination of fatty acid ¹³ C signature. The significantly higher de novo lipogenesis index in the cannabis users group along with a more enriched ¹³ C signature of palmitic acid suggested an increase in lipogenesis. In addition, while serum glucose concentration did not differ between groups, pyruvate and lactate were lower in the cannabis user group, with pyruvate negatively correlating with palmitic acid. Furthermore, the endocannabinoid 2-arachidonoylglycerol was elevated in cannabis users and could contribute to lipogenesis by activating the cannabinoid receptor 1. Because palmitic acid has been suggested to increase inflammation, we measured peripheral cytokines and observed no changes in inflammatory cytokines. Finally, an anti-inflammatory metabolite of palmitic acid, palmitoylethanolamide was elevated in cannabis users. Our results suggest that lipogenic activity is increased in cannabis users; however, future studies, including prospective studies that control dietary intake are required.

Cannabis Use and Prospective Long-Term Association with Anxiety: A Systematic Review and Meta-Analysis of Longitudinal Studies: Usage du cannabis et association prospective à long terme avec l'anxiété: une revue systématique et une méta-analyse d'études longitudinales

OBJECTIVES

Cannabis use is proposed as a risk factor for psychosis and is associated with depressive disorders. However, the relationship between recreational cannabis use and its longitudinal implications on anxiety conditions is less studied. The aim of this investigation is to systematically evaluate published literature and perform a meta-analysis of the data.

METHODS

A systematic search was performed of MEDLINE, Embase, and PsychINFO from inception to May 31, 2020, in addition to a hand search. Longitudinal studies that evaluated the relationship of cannabis use and development of anxiety were included. Where applicable, adjusted odds ratios (ORs) were extracted, pooled, and evaluated using random-effects meta-analysis.

RESULTS

After screening of unique abstracts (n = 6835), the final evaluation included 24 studies, of which 10 reported ORs that were analyzed quantitatively. Cannabis use was significantly associated with increased odds of developing any anxiety conditions (OR = 1.25; 95% CI, 1.01 to 1.54). Cannabis use was not significantly associated with developing generalized anxiety disorder, panic disorder, or social anxiety disorder. Review of studies not reporting OR revealed mixed results but are suggestive of a link between cannabis use and increased rates/severity of anxiety.

CONCLUSIONS

Published evidence suggests that cannabis use is likely associated with increased risk of anxiety in the long term but variability of study designs precludes declaration of a causal relationship. Awareness of this association is of relevance for both clinical practice and mental health policy implementation.

Neurocognitive Correlates of Adolescent Cannabis Use: An Overview of Neural Activation Patterns in Task-Based Functional MRI Studies

Adolescence is dynamic and comprises physiological, psychological, and neurocognitive changes. Notably, many developmentally associated neurobiological changes (e.g., synaptic pruning, myelination) coincide with peak substances use prevalence rates, particularly for cannabis use. Cannabis remains the most commonly used illicit drug among adolescents with 23.9% reporting cannabis use in the last year (Johnston et al., 2019). Adolescents who engage in cannabis use often show poorer neurocognitive performance and alterations in structural and functional brain development as compared to their non-using peers (Jacobus & Tapert, 2014). Over the past several decades, the cognitive domains most consistently associated with cannabis use among adolescents are learning and memory and several facets of executive functioning (e.g., inhibitory control, decision-making). Functional magnetic resonance imaging (fMRI) is a non-invasive method for probing the neural substrates underlying possible cannabis-related changes in cognition. This brief review aims to synthesize recent findings on the relationship between adolescent (≤25 years old) cannabis use and neural response during task-based functional magnetic resonance imaging (fMRI). Findings thus far suggest aberrant, often hyperactive, response to task-based stimuli in youth cannabis users. When considering the future directions of fMRI research with cannabis-using youth, review of existing studies also highlights the need for more prospective research with diverse samples.

Adolescent Substance Abuse, Transgenerational Consequences and Epigenetics

Adolescence is the transitional period between childhood and adulthood and a critical period in brain development. Adolescence in humans is also associated with increased expression of risk-taking behaviors. Epidemiological and clinical studies, for example, show a surge of drug abuse and raise the hypothesis that the adolescent brain undergoes critical changes resulting in diminished control. Determining how substance abuse during this critical period might cause longterm neurobiological changes in cognition and behavior is therefore critically important. The present work aims to provide an evaluation of the transgenerational and multi-generational phenotypes derived from parent animals exposed to drugs of abuse only during their adolescence. Specifically, we will consider changes found following the administration of cannabinoids, nicotine, alcohol and opiates. In addition, epigenetic modifications of the genome following drug exposure will be discussed as emerging evidence of the underlying adverse transgenerational effects. Notwithstanding, much of the new data discussed here is from animal models, indicating that future clinical studies are much needed to better understand the neurobiological consequences and mechanisms of drug actions on the human brains' development and maturation.

Hit the chronic… physical activity: are cannabis associated mental health changes in adolescents attenuated by remaining active?

PURPOSE

High-frequency cannabis use in adolescents has been associated with adult mental illness. In contrast, physical activity has been demonstrated to benefit mental health status. The purpose of this study was to examine whether, within a 1-year prospective study design, changes in cannabis use frequency are associated with changes in mental health, and whether meeting physical activity guidelines moderates these associations.

METHODS

COMPASS (2012-2021) is a hierarchical longitudinal health data survey from a rolling cohort of secondary school students across Canada; student-level mental health data linked from Years 5 (2016/17) and 6 (2017/18) were analysed (n = 3173, 12 schools). Multilevel conditional change regression models were used to assess associations between mental health scores change, cannabis use change and physical activity guideline adherence change after adjusting for covariates.

RESULTS

Adopting at least weekly cannabis use was associated with increases in depressive and anxiety symptoms and decreases in psychosocial well-being. Maintaining physical activity guidelines across both years improved psychosocial well-being regardless of cannabis use frequency, and offset increases in depressive symptoms among individuals who adopted high frequency cannabis use. Physical activity adherence had no apparent relationship with anxiety symptoms.

CONCLUSION

Regardless of the sequence of events, adopting high frequency cannabis use may be a useful behavioural marker of current or future emotional distress, and the need for interventions to address mental health. Physical activity adherence may be one approach to minimizing potential changes in mental health associated with increasing cannabis use.

Cannabis use and the risk of anxiety and depression in women: A comparison of three Swedish cohorts

BACKGROUND

The associations between cannabis use and anxiety or depression remain unclear. If cannabis affects these conditions, it is of interest to examine possible changes in cannabis use over time, in relation to anxiety and depression, as cannabis potency has increased in recent decades.

METHODS

Cohorts from the Women and Alcohol in Gothenburg study (n = 1 100), from three time periods were used to examine associations over time between cannabis use and anxiety and depression. Logistic regression analyses were used and relative excess risk due to interaction (RERI) was calculated to examine potential additive interactions between period of cannabis use, cannabis use, and anxiety or depression.

FINDINGS

Cannabis use was associated with anxiety in the oldest cohort (examined 1986-1992, born 1955/65), OR = 5.14 (1.67-15.80, 95 % CI), and with both anxiety and depression in the youngest cohort (examined 2000-2015, born 1980/93), OR = 1.66 (1.00-2.74, 95 % CI) and 2.37 (1.45-3.86, 95 % CI), respectively. RERI was significant between cannabis use and depression in the youngest cohort when compared with older cohorts (1.68 (0.45-2.92, 95 % CI)).

LIMITATIONS

Cross-sectional data prevent statements on causality, though between-cohort comparisons are possible.

CONCLUSION

The association between cannabis use and depression becomes more pronounced when adding the effect of period of use rather than looking at the effect of cannabis use itself. This study provides clinicians and public health workers with scientifically underpinned knowledge regarding the link between cannabis use and depression, of particular importance given increasing cannabis potency.