Cannabis legalization and early adolescent expectancies: Findings from the adolescent brain cognitive development...

Cannabis legalization in the U.S. has introduced an ongoing public health challenge. Among adults, cannabis legalization is associated with increased cannabis use and shifting attitudes toward cannabis use. These expectancies, or personal beliefs about the outcomes of a behavior, are both positive (e.g., increased relaxation) and negative (e.g., cognitive impairment). With rapid shifts in state-level cannabis legislation, the associations of these policies with adolescent cannabis expectancies are unknown.

We conducted a cross-sectional analysis of the Adolescent Brain Cognitive Development Study from the Year 2 follow-up (2018-2020, average age: 12 years) via Poisson analysis to investigate the association between state-level cannabis legalization and positive and negative cannabis expectancies via the Marijuana Effect Expectancy Questionnaire-Brief, controlling for sociodemographic covariates.

A total of 8356 participants lived in states with no (NCL, 34%), medical (MCL, 39%), or recreational (RCL, 27%) cannabis legalization in place. Compared to NCL states, participants from both MCL (ARR=1.09, 95%CI: 1.07-1.11, p < 0.001) and RCL (ARR=1.08, 95%CI: 1.06-1.11, p < 0.001) states were more likely to report positive cannabis expectancies. Those from MCL states were less likely to report negative cannabis expectancies (ARR=0.98, 95%CI: 0.97-0.99, p = 0.017).

These findings indicate that early adolescents from states with medical and recreational cannabis legalization may have higher positive cannabis expectancies compared to those from states with no cannabis legalization. Our results may have important implications for public health officials, policymakers, and clinicians working to help adolescents understand the effects of cannabis use.