Probability and Predictors of Cannabis Use Disorder Among Cannabis Users with Depressive Disorders

Introduction and Aims: Cannabis use and cannabis use disorders (CUD) have been increasing in the US. Recent studies have aimed to assess the rates of transition from cannabis use to CUD over time across several sociodemographic corelates (e.g., age and sex). Depressive disorders are a strong clinical correlate of cannabis use, and carry a substantial burden of disease. The underlying mechanisms involved in the relationship between depression and cannabis use are still not fully understood. While certain studies have examined changes in rates of cannabis among depressed and non-depressed individuals over time, no studies have quantified the effect of depressive disorders on cannabis users’ transition rates to CUD. Methods: Participants were individuals ≥18 years interviewed in the National Epidemiologic Survey on Alcohol and Related Conditions-III in 2012–2013. Survival plots assessed the probability of transition from cannabis use to CUD over time. Differences in probability of transition to CUD was assessed among cannabis users with and without predisposing depressive disorders ( major depressive disorder or dysthymia with an initial diagnosis prior to onset of cannabis use). Results: Among lifetime cannabis users (N = 11,272), the 5-year probability of transition to CUD was approximately 3.9% for cannabis users without depressive disorders and 7.3% for those with a depressive disorder. A higher probability of transition from cannabis use to CUD among those with a predisposing depressive disorder was observed over all time points that were examined in the study. Cannabis users with depressive disorders who were male and belonging to an early-onset of cannabis use age group (<16) transitioned significantly more rapidly to CUD than females and those with a later- onset of cannabis use Conclusions: This is the first study to explore the effect of depressive disorders on rates of transition from cannabis use to the DSM-5 CUD diagnosis. The current study identified specific predictors of this transition. Findings inform clinicians who treat individuals with depressive disorders that initiate cannabis use as to the risk of developing CUD and the need for harm prevention targeted at this specific population.