Please use this link to access this publication. Abstract Background The current study used U.S. young adult data to examine overall and age group-specific historical trends in (a) mean perceived risk and disapproval of cannabis use, and (b) risk/use and disapproval/use associations. Methods Data were collected from 2011 to 2022 from 16,492 respondents aged 19–30 in the national Monitoring the Future panel study. Trends in mean risk and disapproval overall and by age group (19–22, 23–26, 27–30) were modeled. Models regressing any past 30-day cannabis use on risk and disapproval controlled for sex, race/ethnicity, college education, population density, state cannabis policy, region, and year....