Trends in marijuana edible consumption and perceptions of harm in a cohort of young adults

Background: Rates of marijuana legalization have increased rapidly in recent years resulting in the marketing of alternative products like edibles that do not involve inhaling smoke. Edibles however pose unique public health challenges due to their greater risk for over-intoxication. Methods: 1858 young adults were surveyed every six months from 2016 to 2018. Logistic regression models examined trends in use and perceptions of harm. Chi-squared tests compared demographic and behavioral characteristics of edible users and non-users by frequency of marijuana use. Results: Perceptions of no harm from edibles increased (25.4%, 27.3%, 26.7%, 28.4%, 29.6%; p = 0.006) while it declined for smoking marijuana (12.2%, 13.5%, 11.7%, 10.6%, 9.1%; p < 0.001). Among non-daily marijuana users, edible use increased (20.3%, 24.8%, 30.5%, 36.2%, 36.6%; p < 0.001) while smoking marijuana declined for both daily and non-daily users. Among daily users, edible users were more likely to use all modes of consumption than non-edible users. Among non-daily users, edible users were less likely to smoke marijuana and perceive harm from edibles and were more likely to perceive harm from smoking marijuana and have visited a dispensary than non-edible users. Conclusions: Edibles are increasingly consumed and perceived to not be harmful, despite the greater danger of over-intoxication. However, daily use of edibles alone is uncommon. The finding that edible users were more likely to have visited a dispensary provides a potential intervention point for consumer education. Strong scientific evidence is needed to guide policymakers in best practices for communicating knowledge and potential harms of these products.