Grant: Canada Postdoctoral Research Award (CPRA) program

Road traffic crashes are the leading cause of death among young Canadians aged 16-24, with cannabis-impaired driving now surpassing alcohol as the primary concern. Nearly half (44.4%) of young drivers killed on Canada's roads test positive for cannabis, and 25% of young cannabis users report driving under the influence of cannabis (DUIC). Despite the higher crash risk, youth express the least concern towards DUIC compared to other age groups, mainly due to limited awareness and low perceived risk. Adding to this issue, there has been a recent decline in youth-focused DUIC prevention programs in Canada, and fewer youth report seeing cannabis-related public health messages in 2023 compared to 2019. To address this urgent need for targeted DUIC education, I developed High Alert, a novel smartphone-based educational intervention designed to reduce youth DUIC. High Alert consists of four 5-7-minute interactive, self-paced modules covering: (i) how cannabis affects driving, (ii) risks of DUIC, (iii) strategies for avoiding DUIC, and (iv) ways to reduce risky cannabis use. Results from a pilot trial (n = 102, 55% female) suggest that High Alert is feasible, acceptable, and may help reduce youth DUIC, supporting the need for a larger trial. The proposed study will evaluate High Alert in a large-scale randomized controlled trial involving 324 Ontario youth who report frequent DUIC (i.e., over 3 times in the past 90 days). Participants will be randomly assigned to one of three groups: High Alert, publicly available DUIC infographics (active control), or a no-contact control. All participants will be followed over six months to measure cannabis use, DUIC frequency, and related beliefs (e.g., attitudes, risk perceptions, social norms). The main aim is to determine if DUIC differs between groups. As cannabis is now legal, addressing DUIC among youth is critically needed. If effective, High Alert could help reduce youth DUIC and improve road safety in Canada.