The effects of expectancy-challenge interventions on binge drinking among college students: a systematic review and meta-analysis

College binge drinking remains prevalent and harmful, and expectancy-challenge interventions (ECIs) aim to reduce it by modifying alcohol outcome expectancies (AOEs), a proximal cognitive target implicated in this high-risk behavior. This meta-analysis evaluated ECI effects on binge drinking and AOEs in college students. We conducted a PRISMA-compliant, PROSPERO-registered systematic review and meta-analysis of randomized controlled trials comparing ECIs (experiential, didactic, or digital formats) to non-alcohol control conditions. Eight trials were included. At approximately one month post-intervention, ECIs yielded a small but significant reduction in binge-episode frequency (Hedges' g = -0.20; 95% CI: -0.33 to -0.07). Immediate expectancy changes were consistent with theoretical predictions: positive expectancies decreased (g = -0.50), while negative expectancies increased (g = 0.27), with attenuated effects at one month. Evidence for sustained behavioral effects at 3-6 months was limited and not statistically significant. Subgroup analyses revealed no consistent moderation by delivery format, control type, or intervention modality. Most outcomes were based on few trials, especially long-term and subgroup results. These findings suggest that ECIs can shift alcohol expectancies and reduce high-risk drinking in the short term. Scalability via classroom or digital delivery may support broader public health application. To enhance durability, future trials should consider adding booster or maintenance components and use optimization strategies to refine core elements.