Just-in-Time Adaptive Interventions for Adolescent and Young Adult Substance Use: A Systematic Review

This systematic review examines the characteristics, feasibility, acceptability, and efficacy of just-in-time adaptive interventions (JITAIs) for adolescent and young adult (AYA) substance use. A systematic search identified studies published between January 2000 and September 2023 using terms related to substance use, AYA, and JITAI. Peer-reviewed studies reporting data on JITAIs for substance use in AYA (ages 13-25) were included. Intervention elements, substance type, feasibility, acceptability, and efficacy outcomes were extracted. Of 6,755 screened titles and abstracts, six studies with 168 participants met eligibility. Targeted substances included alcohol (k = 1), tobacco (k = 1), cannabis (k = 2), and polysubstance use (k = 2). All studies used ecological momentary assessment. Intervention timing varied: three studies used prespecified time intervals, two used random times, and one delivered messages at a fixed daily time. Content emphasized goal-relevant feedback, motivational interviewing, and self-efficacy enhancement. Participants generally found interventions engaging, with adequate retention and compliance rates. Our findings support preliminary JITAI efficacy, with three studies reporting significant substance use reductions during the intervention and two reporting significant reductions compared to control groups. JITAIs also appear feasible and acceptable for AYA substance use. JITAI research is still underdeveloped in the scientific literature. Future research should explore moderating factors of JITAI efficacy, engagement strategies to improve adherence, and establish a consistent JITAI definition.