Motives for and impairment associated with alcohol and marijuana use among college students

Introduction: Alcohol and marijuana use are prevalent on college campuses. As recreational marijuana use is legalized, more undergraduate students may use marijuana in combination with alcohol. The motives for, frequency of, and impairment associated with dual use (alcohol and marijuana) compared to alcohol-only use may differ. We examined motives for, frequency of, and impairment associated with alcohol use and dual use at a university in a state where recreational marijuana has been legalized. Method: Undergraduate college students completed an anonymous online survey (N = 430) concerning alcohol and marijuana frequency, motives, and impairment. Students were classified as either alcohol-only users (n = 279) or dual users (n = 151). Results: Analyses indicated that among alcohol-only users, social motives predicted more alcohol use, while among dual users, enhancement motives predicted more alcohol and marijuana use and impairment. Coping motives predicted more marijuana use among dual users, but not more alcohol use. Frequency of alcohol and marijuana use predicted more impairment across both the alcohol-only and dual users. Conclusions: Future research should examine the influence of marijuana use over time to understand how motives may change for previous alcohol-only users.