Personality-targeted school program reduced cannabis-related harms over 7 years | Research

The takeaway

The PreVenture program, a brief personality-targeted intervention delivered in schools, reduced the growth of cannabis-related harms by 22% over 7 years but did not significantly reduce cannabis use itself.

People interested in youth drug prevention programs and harm reduction approaches.

22% reduction in cannabis harms over 7 years from a 3-hour intervention

What the researchers found

The PreVenture group had 22% lower odds of annual cannabis-related harms compared to controls (OR=0.78, 95% CI: 0.65-0.92). However, there were no significant differences in cannabis use (OR=0.84, 95% CI: 0.69-1.02) or stimulant use (OR=1.07, 95% CI: 0.91-1.25) growth over the 7-year period.

Why it matters

Most drug prevention programs show only short-term effects. Finding that a brief, two-session intervention reduced cannabis harms over 7 years into early adulthood is notable, even though it did not reduce use itself. Reducing harms without eliminating use aligns with harm reduction approaches.

The numbers in context

438 students at baseline (mean age 13.4 years). Two 90-minute sessions. 7-year follow-up. Cannabis harms: OR=0.78 (95% CI: 0.65-0.92). Cannabis use: OR=0.84 (nonsignificant). Retention: 51-79% over 7 years.

How the study worked

Cluster randomized controlled trial in 14 Australian schools. High-risk students (scoring high on anxiety sensitivity, negative thinking, impulsivity, or sensation seeking) received PreVenture (two 90-minute sessions one week apart) or usual health education. Outcomes tracked from baseline through 7 years post-intervention.

What this study cannot tell us

Substantial attrition over 7 years (retention as low as 51%). The intervention did not reduce cannabis or stimulant use rates. Only high-risk students were included, limiting generalizability. Australian context may differ from other countries.

How to read the evidence

Cluster RCT with 7-year follow-up, though substantial attrition and the cluster design with only 14 schools limit statistical power. The harm reduction finding is significant but the use reduction finding is not.

When this study was published

Published in 2024 with 7-year follow-up data from a trial conducted 2012-2019.

The bigger picture

Personality-targeted prevention is a growing field that matches interventions to individual risk profiles rather than using one-size-fits-all approaches. This 7-year result suggests that even brief, targeted interventions during adolescence can have lasting protective effects on how people experience cannabis consequences.

Questions still open

How does PreVenture reduce harms without reducing use? Would booster sessions improve the effect on actual use rates? Would delivering the intervention later in adolescence, closer to when cannabis use peaks, be more effective?

Common questions

What is PreVenture?

PreVenture is a brief prevention program delivered in schools that targets specific personality traits (anxiety sensitivity, negative thinking, impulsivity, sensation seeking) linked to substance misuse risk. It consists of just two 90-minute group sessions.

Did PreVenture stop teens from using cannabis?

Not quite. The program did not significantly reduce cannabis use rates, but it did reduce cannabis-related harms by 22% over 7 years, suggesting it helped teens use more safely rather than abstain entirely.

Read the original research

Effect of a selective personality-targeted prevention program on 7-year illicit substance related outcomes: A secondary analysis of a cluster randomized controlled trial.

Drug and alcohol dependence, 258, 111266

View on PubMed ↗Publisher’s paper ↗

Citation

Champion, Katrina E; Debenham, Jennifer; Teesson, Maree; Stapinski, Lexine A; Devine, Emma; Barrett, Emma L; Slade, Tim; Kelly, Erin V; Chapman, Cath; Smout, Anna; Lawler, Siobhan; Castellanos-Ryan, Natalie; Conrod, Patricia J; Newton, Nicola C. (2024). Effect of a selective personality-targeted prevention program on 7-year illicit substance related outcomes: A secondary analysis of a cluster randomized controlled trial.. Drug and alcohol dependence, 258, 111266. https://doi.org/10.1016/j.drugalcdep.2024.111266