Effects of a Parent-Based Intervention on Positive and Negative Alcohol and Cannabis Consequences among First Year College Students

Alcohol and cannabis use among college students is linked to various negative consequences, including poor academic performance, injury, driving under the influence, and hospitalization. Additionally, positive consequences of alcohol and cannabis use are important to consider as they are associated with increased subsequent use. This study examined the effects of a self-directed, parent-based handbook intervention on first-year college students’ negative and positive alcohol and cannabis consequences, as well as whether the effects of the intervention differed by student gender. Parent-student dyads were randomized to either the control condition (n = 309) or handbook condition (n = 609) across two cohorts. Parents received the handbook, designed to promote family protective factors, during the summer before their student started college at a large public university. Students completed surveys during spring of their senior year of high school (baseline) and their first semester of college (time 2). Zero-inflated Poisson regression models examined intervention effects on negative and positive alcohol and cannabis consequences at time 2, controlling for baseline consequences, gender, and cohort. Moderation analyses examined if the relationship between the intervention and consequences differed by gender. Compared to the control group, students in the intervention group were more likely to report zero negative alcohol consequences, zero negative cannabis consequences, zero positive alcohol consequences, and zero positive cannabis consequences at time 2. Additionally, they reported fewer negative cannabis consequences, positive alcohol consequences, and positive cannabis consequences at time 2. Further, the handbook had a stronger effect in reducing positive consequences among males relative to females. Findings suggest that this low-cost parent handbook intervention is an effective strategy to reduce alcohol- and cannabis-related harms among first-year students. Further, reducing positive consequences may contribute to lowering subsequent use and consequences.