Cannabis Use is an Independent Risk Factor for Manic Episode: A Report from 380,265 Bipolar Inpatients.

Objectives: To evaluate the odds for bipolar disorder (BP) mania and depression-related hospitalization due to cannabis use disorders (CUD).

Methods: We conducted a cross-sectional study using the national inpatient sample (NIS), and included adult BP hospitalizations sub-grouped by manic (N = 209,785) versus depressive episodes (N = 170480). A logistic regression model was used to evaluate adjusted odds ratio (aOR) of association between CUD and BP-mania-related hospitalizations and was adjusted for demographics confounders, psychiatric comorbidities and other substance use disorders (SUD).

Results: Comorbidities were less prevalent in BP mania compared to BP depression: anxiety disorders (22.7% vs. 35.3%), PTSD (8.7% vs. 14.3%), and personality disorders (15.4% vs. 20.5%). Among SUD, methamphetamine (aOR 1.27, 95%CI 1.22 - 1.32) and CUD (aOR 1.53, 95%CI 1.50 - 1.56) had increased odds for hospitalization for BP mania.

Conclusion: CUD increases the odds for hospitalization for BP manic episode by 53%. Due to the rising prevalence of cannabis use among patients with BP it is important to provide substance use counseling/psychoeducation and discourage cannabis use among youth to prevent long-term adverse consequences.