Abstract College students’ risky drinking and cannabis use are major public health problems. Almost 80% of college students report consuming alcohol in the past year and more than 1 in 3 report heavy episodic drinking in the past month. Reports also show that college is a high-risk window for cannabis use. This is highly concerning considering that the potency of present-day cannabis has markedly increased, cannabis use and consequences have also risen, and availability continues to grow due to increased legalization across the U.S. Further, a number of studies have shown an increase in co-use of alcohol and cannabis (use of both substances in the same day), which results in significantly more problems compared to either alcohol-only or cannabis-only use. Our brief parent-based intervention for college students has shown efficacy in reducing risky drinking, but it does not currently have content to address cannabis use or co-use of alcohol and cannabis. Our review of the literature and research in progress reveals there are no studies examining the efficacy of parent interventions to reduce cannabis use in this age group. The proposed research will address this omission, curb the problematic trends noted above, and move the field forward by testing a modified version of our parent-intervention that includes content for parents to have broader discussions about alcohol and cannabis use (referred to as e-PBI+). To assess interest in the college-level cannabis parent-intervention materials, we conducted a pilot survey of 40 college health administrators and all 40 indicated that they have a need for and would implement a parent-intervention that included content on cannabis (see letters of support). We then conducted a pilot RCT study on the e-PBI+ (versus a control condition) and observed preliminary evidence that parents found the e-PBI+’s additional cannabis content interesting and useful, conversations with their students were well received, and more importantly, students were less likely to engage in cannabis use post-intervention. Taken together, these data provide support for further examination of the e-PBI+. Our proposed study will use a rigorous RCT design to examine: 1) The efficacy of the e-PBI+ at 3, 6, 9, and 12 months post-baseline relative to an active comparison condition (our evidence-based parent intervention, the e-PBI), and an attention-matched-control condition (e-AC), on reducing alcohol and cannabis use and consequences (efficacy; Aim 1); 2) Examine the process by which the e-PBI+ influences parents’ and college students’ behaviors (mediation; Aim 2); and 3) Examine subgroups for whom the e-PBI+ is more versus less effective (moderation; Aim 3). To the extent that the research is successful, it will provide an easy to implement and low-cost parent-intervention that provides new cannabis content for parents to have discussions with their college-bound teens about alcohol and cannabis.

Project Narrative Despite the majority of college students being underage for drinking, almost 80% report consuming alcohol in the past year and more than 1 in 3 report heavy drinking in the past month. Reports also show college is a high-risk window for cannabis use and consequences (including using both substances in the same day), which is highly concerning considering that the potency of present-day cannabis has markedly increased and availability continues to grow due to increased legalization across the U.S. The proposed research will address these important public health problems by testing a modified version of our parent-intervention that includes content for parents to have broader discussions about alcohol and cannabis use.