Historical change in associations between perceived risk, disapproval, and use of cannabis among young adults ages 19-30, 2011-2022

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. Age group differences and historical trends in regression estimates from year-specific models were examined. Results: From 2011 to 2022, overall mean perceived risk decreased from 3.08 (just over moderate) to 2.50 (between slight and moderate); mean disapproval decreased from 2.21 (between disapprove and strongly disapprove) to 1.66 (between don't disapprove and disapprove). Higher risk and disapproval were independently associated with lower odds of past 30-day cannabis use overall (AORs 0.86 and 0.76, respectively); controlling for sociodemographics and state policy had virtually no impact on association strength. There were no significant age-related association differences. The risk/use association weakened from AOR 0.84 in 2011 to AOR 0.91 in 2022; the disapproval/use association remained stable (AORs 0.753 and 0.749). Conclusions: Young adults now perceive cannabis as less risky and are less disapproving of using than they were a decade ago. Perceived risk has weakened as a cannabis use risk factor over time; disapproval has remained a stable risk factor.