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.

Clinical and demographic factors associated with delayed diagnosis of bipolar disorder: Data from Health Outcomes and Patient Evaluations in Bipolar Disorder (HOPE-BD) study.

BACKGROUND: The diagnosis of Bipolar Disorder (BD) is frequently delayed. In this study, we aimed to examine the clinical and demographic factors associated with delayed diagnosis of BD, defined as the difference between the age at first mood episode (depressive, manic, or hypomanic) and the age at the correct diagnosis of BD, using data from a Canadian multicentre naturalistic study. METHODS: The sample included 192 patients with Bipolar I Disorder (BD-I) and 127 with Bipolar II Disorder (BP-II) who participated in the Health Outcomes and Patient Evaluations in Bipolar Disorder (HOPE-BD) study. Sociodemographic characteristics and clinical features that had been previously associated with delayed diagnosis of BD were included in the analysis. RESULTS: The median delay in diagnosis was 5.0 years in BD-I and 11.0 years in BD-II. Clinical factors such as earlier age of onset, lifetime suicide attempts and comorbid anxiety disorders were associated with a longer delay, whereas the presence of lifetime psychotic symptoms and psychiatric hospitalizations were associated with a shorter delay. Quantile regression analysis showed older age at which professional help was first sought and younger age of onset as predictors of increased delay in diagnosis of BD-I and BD-II. Depression as first episode predicted longer delay in diagnosis of BD-I but not BD-II. CONCLUSION: Our findings identified the ongoing lag in identification of a BD diagnosis and the clinical markers most associated with this delay, highlighting the need for implementation of strategies for early identification and interventions in BD.

Grey matter abnormalities in first-episode mania: A systematic review and meta-analysis of voxel-based morphometry studies.

OBJECTIVES: It has been proposed that different stages of bipolar disorder may be underpinned by distinct neurobiological substrates. However, structural neuroimaging studies in early stages of the illness are limited by small sample sizes yielding inconsistent findings. The purpose of this systematic review and meta-analysis, therefore, was to identify regional grey matter volume (GMV) changes that are consistently associated with first episode of mania (FEM). METHODS: Following PRISMA guidelines, we conducted a systematic search of the literature to identify Voxel-Based Morphometry (VBM) studies in FEM patients compared with healthy individuals. We then conducted a voxel-wise meta-analysis using Seed-based d-Mapping technique. Finally, we performed univariate meta-regression analyses to explore the potential effects of moderator variables including age, gender, and percentage of lithium users on GMV alterations. RESULTS: We identified 15 VBM studies and included 12 studies in the meta-analysis. Four studies found no regional differences in GM volumes while other 11 studies reported volume changes in frontal and temporal regions as well as anterior cingulate cortex (ACC), cerebellum and basal ganglia. The meta-analysis revealed a single cluster of GMV reduction in bilateral pregenual ACC in patients with FEM compared to healthy individuals (P < .001). The Egger's test showed no evidence of publication bias at peak voxel level (P = .447). Meta-regression analyses revealed no significant effects of moderators evaluated. CONCLUSIONS: Structural brain changes are evident in the early stages of bipolar disorder. GMV reduction in bilateral pregenual ACC is the most consistent finding in VBM studies of FEM.