Despite having made some strides towards reducing adolescent drinking rates, illicit substance use and substance use disorders remain significantly above national targets for health promotion and disease prevention in Canada. Of particular concern is the emerging prescription drug use crisis in Canada. Adolescence and early adulthood is the usual age of onset of prescription drug abuse, with 15-25 year olds reporting the highest and fastest growing rates of prescription drug misuse of any age group in the country.

There is a pressing need for effective substance abuse prevention in Canada, particularly targeted intervention strategies designed to help those most at risk of transitioning to substance use disorders. Yet, very few programs have been developed to effectively address illicit drug use among adolescents and even fewer have been evaluated with respect to efficacy in preventing non-medical prescription drug use. Moreover, less than 15% of North American adolescents are exposed to evidence-based prevention interventions.

This cluster randomized controlled trial involves four sites: a coordinating site in Quebec and three study sites in British Columbia, Ontario and Nova Scotia. The three sites will each recruit nine high schools randomized to three intervention conditions. Students from grade 10 enrolled in these schools in 2019, 2020 and 2021 will be invited to participate, resulting in approximately 4050 students across 27 schools each year, a total of 12,150 students over three years. Eligible students (approximately 45%) at each school will be invited to attend two PreVenture workshops.

To accelerate evidence needed to increase scale-up of this effective program this study will involve both an Effectiveness trial and an Implementation Facilitation trial. Firstly, the study will test the effectiveness of PreVenture when disseminated through a Train-the-Trainer implementation model. Consenting grade 10 students will be assessed on measures of past 12-month substance use onset as well as severity of use. Secondly, to address questions about program sustainability and scale-up, the study will apply state-of-the-art methods in implementation science to examine a novel Implementation Facilitation component to support effective and sustained delivery of PreVenture.