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

Abstract

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.

Cannabis use and mood disorders: a systematic review

“…Our review serves as an extension of prior reviews and meta-analyses by identifying the associations between cannabis use and depressive and manic symptoms across both clinical and non-clinical populations. While previous reviews have focused particularly on specified clinical populations ( 105 ), or solely examined the prospective risk associated with cannabis use and mood disorders ( 106 ), our review uniquely bridges these perspectives. Furthermore, our review conducts a thorough investigation into the multifaceted impact of cannabis on a range of outcomes within MDD and BD.…”

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

“…A recent review indicates that lifetime cannabis use (CU) was very frequent among persons with BD, ranging from 50–66% using cannabis over their lifetime [ 8 ]. This reported rate of lifetime cannabis use (LT-CU) is as much as sevenfold higher in individuals with BD compared to people without BD (71.3%, OR 6.8, CI, 5.41 to 8.52) [ 9 ], while cross-sectional prevalence rates of CU varied from 3.3% to approximately 18% [ 8 ].…”

“…Previous epidemiological studies [ 8 ] indicated that CU is also associated with the worsening of mood disorder symptoms in a dose-dependent manner [ 10 ], suggesting that CU and use disorders, like alcohol use disorders [ 16 , 17 ], have a detrimental influence on the development and course of bipolar disorders.…”

The Canadian Network for Mood and Anxiety Treatments (CANMAT) Task Force Report: Serotonergic Psychedelic Treatments for Major Depressive Disorder

“…As such, the evidence for ketamine, cannabis and MDMA are not reviewed herein; however, CANMAT has recently reviewed and provided recommendations for ketamine 14 and cannabis. 15…”

“…As such, the evidence for ketamine, cannabis and MDMA are not reviewed herein; however, CANMAT has recently reviewed and provided recommendations for ketamine 14 and cannabis. 15 The objective of the present CANMAT Task Force review is to summarize and synthesize evidence for the use of psychedelics in depression. We follow the previous CANMAT question and answer format, focusing on areas that are of greatest importance to clinicians, researchers and individuals with lived experience.…”