Patterns of cannabis use and clinical correlates among individuals with Major Depressive Disorder and Bipolar Disorder

Background Major Depressive Disorder (MDD) and Bipolar Disorder (BPD) are the most severe mood disorders globally. Previous reports indicate high co-occurrence of cannabis use and cannabis use disorders (CUDs) associated with both disorders, yet studies comparing patterns of cannabis use between individuals with MDD and BPD are scarce. Methods Data were drawn from Wave 1 (2001–2002) of the National Epidemiologic survey on Alcohol and Related Conditions (NESARC). Cannabis users who qualified for a diagnosis of past-year MDD (N = 217) were compared to those with BPD (N = 168) in frequency and daily dose of cannabis use, rates of comorbid psychiatric disorders including specific criteria of CUDs, treatment utilization and suicidality. Results Among past-year cannabis users, individuals with BPD reported using cannabis more frequently and smoking more joints per day compared to those with MDD. They were also more likely to suffer from comorbid personality disorders and qualify for specific CUD-criteria, including use in physically hazardous situations and unsuccessful efforts to control substance use. Conclusions Our results indicate that individuals with BPD may present more intensive patterns of cannabis use compared to those with MDD. This may have potential effects on the course of BPD and should be further explored in longitudinal studies.