Predictors of Cannabis Use Change in Mexican First-Year University Students: A 12-Month Follow-Up Study

Evidence on changes in cannabis use (CU) patterns among university students remains limited. This prospective study examined predictors of changes in CU frequency (initiation, maintenance, increase, decrease, and cessation) from baseline to a 12-month follow-up in 3,234 Mexican first-year university students. Bivariate and multivariate logistic regression and repeated-measures linear mixed models were used to identify predictors of CU change frequency, accounting for within-individual effects over time. Among students with lifetime CU (n = 635), initiation and cessation were the most common trajectories. Initiation was associated with stronger high-school peer support (AOR = 1.70), alcohol use disorder symptoms (AOR = 2.83), and no religious affiliation (AOR = 1.46). Cessation was associated with older age (AOR = 2.35) and lifetime cocaine use (AOR = 2.22). Older age, critical/quarrelsome personality, and illicit drug use predicted higher baseline CU frequency but steeper subsequent declines. Findings underscore the first university year as a critical transition period and highlight the time-varying effects of CU risk and protective factors.