Greater risk for frequent marijuana use and problems among young adult marijuana users with a medical marijuana card

Abstract

BackgroundThis study compared young adults with and without a medical marijuana (MM) recommendation from a provider (“MM card”) on their developmental trajectories of frequent marijuana use and marijuana-related problems in young adulthood. MethodsThe analytic sample consists of young adult past month marijuana users (N = 671) who were part of a larger, diverse, and predominantly California cohort. Analyses are based on data from seven surveys completed from ages 13–19. ResultsAt age 19, 28% of participants reported having an MM card to legally purchase marijuana from an MM dispensary. A multiple group latent growth model indicated that young adults who had an MM card showed steeper increases in frequent marijuana use (i.e., 20–30 days of use in the past month) from ages 13–19 compared to young adults who did not have an MM card. Logistic regression models that matched MM cardholders and non-MM cardholders on individual sociodemographic characteristics found that MM cardholders were more likely to report marijuana negative consequences, selling marijuana/hashish, and driving under the influence of marijuana in the past year. In addition, MM cardholders were more likely to have tried cutting down or quitting in the past 3-months. ConclusionsAmong young adult marijuana users, those with an MM card had a higher risk profile for marijuana use and related problems compared to those without an MM card. Given expanding state legalization of MM, this issue warrants further attention.