A European school drug prevention program worked through changing attitudes and norms, but weakly | Research

The takeaway

The Unplugged school-based prevention program reduced substance use in European youth by modifying attitudes toward drugs, refusal skills, and perceptions of peer use, but the mediating effects were generally weak.

Read this if you are interested in how school-based drug prevention programs work and whether they actually change behavior.

Attitudes, refusal skills, and peer norms mediated program effects, but weakly

What the researchers found

In a randomized trial across 143 schools in seven European countries (7,079 students), the Unplugged social influence-based prevention program was compared to usual health education. The program successfully changed several intermediate factors: participants endorsed less positive attitudes toward drugs, held fewer positive beliefs about substances, perceived less peer substance use, gained knowledge, and improved refusal skills for tobacco.

These changes appeared to mediate the program's effects on actual substance use, with decreased positive attitudes, increased refusal skills, and corrected norms about peer tobacco and cannabis use acting as mediating pathways. However, the mediating effects were generally weak and some were only marginally significant.

Why it matters

Understanding how prevention programs work (not just whether they work) guides program improvement. Knowing that attitude change and norm correction are active mechanisms, even if weak, helps developers focus on strengthening these specific components.

The numbers in context

143 schools in 7 European countries. 7,079 students. Program effects were mediated through attitudes, refusal skills, and normative perceptions. Mediating effects were generally weak with some only marginally significant.

How the study worked

Cluster-randomized trial in 143 schools across seven European countries with 7,079 pupils. Multilevel multiple mediation models examined whether changes in knowledge, attitudes, norms, and refusal skills mediated effects on tobacco, alcohol, and cannabis use at 3 months post-intervention.

What this study cannot tell us

Only 3-month follow-up was assessed. Weak mediation effects suggest other unmeasured factors may be more important. Cross-country variation was not fully explored. Self-reported substance use may be biased.

How to read the evidence

Large multinational cluster-randomized trial with mediation analysis, though short follow-up and weak mediation effects limit practical significance.

When this study was published

Published in 2014.

The bigger picture

School-based prevention programs are widely implemented but have modest effect sizes. This study confirmed that social influence approaches work through their intended mechanisms but suggested that stronger techniques may be needed to produce meaningful behavior change.

Questions still open

Do the mediating effects strengthen with booster sessions? Which of the seven countries showed the strongest effects? Would a longer follow-up show fading or strengthening of effects?

Common questions

Do school drug prevention programs work?

The Unplugged program showed some effect on reducing substance use across seven European countries, working through changing attitudes, refusal skills, and perceptions of peer use. However, the mediating effects were weak, suggesting modest real-world impact.

How do prevention programs reduce drug use?

This study found that Unplugged worked by decreasing positive attitudes toward drugs, increasing refusal skills, and correcting overestimates of peer substance use. These social influence mechanisms partially explained the program's effect on actual use.

Read the original research

Short-term mediating factors of a school-based intervention to prevent youth substance use in Europe.

The Journal of adolescent health : official publication of the Society for Adolescent Medicine, 54(5), 565-73

View on PubMed ↗Publisher’s paper ↗

Citation

Giannotta, Fabrizia; Vigna-Taglianti, Federica; Rosaria Galanti, Maria; Scatigna, Maria; Faggiano, Fabrizio. (2014). Short-term mediating factors of a school-based intervention to prevent youth substance use in Europe.. The Journal of adolescent health : official publication of the Society for Adolescent Medicine, 54(5), 565-73. https://doi.org/10.1016/j.jadohealth.2013.10.009