Depression and marijuana use disorder symptoms among current marijuana users

Background: Depression is one of the most consistent risk factors implicated in both the course of escalating substance use behaviors and in the development of substance dependence symptoms, including those associated with marijuana use. In the present study, we evaluate if depression is associated with marijuana use disorder symptoms across the continuum of marijuana use frequency. Methods: Data were drawn from six annual surveys of the National Survey of Drug Use and Health to include adults who reported using marijuana at least once in the past 30 days (N = 28,557). Results: After statistical control for sociodemographic characteristics and substance use behaviors including marijuana use, alcohol use, smoking, and use of illicit substances other than marijuana, depression was positively and significantly associated with each of the marijuana use disorder symptoms as well as the symptom total score. Adult marijuana users with depression were consistently more likely to experience marijuana use disorder symptoms and a larger number of symptoms, with the magnitude and direction of the relationship generally consistent across all levels of marijuana use frequency from 1 day used in the past month to daily marijuana use. Conclusions: Depression is a consistent risk factor for marijuana use disorder symptoms over and above exposure to marijuana suggesting that depressed individuals may represent an important subgroup in need of targeted substance use intervention.