The largest European drug education trial ever conducted tested whether US-style social influence programmes would prove effective in Europe. There were probably some real successes, but these were limited and may have been artefacts of the implementation and analysis of the study.
Funded at European level by the European Commission, the European Drug Addiction Prevention trial (EU-Dap) aimed to test whether Unplugged – a ‘social influence’ school-based drug prevention programme of the kind developed in the USA – would prove effective in Europe. Across seven countries and 170 schools it recruited 7079 12–14-year-old pupils, the largest sample ever in a European drug education trial.
By design, at entry to the study none of the schools were implementing specific drug prevention interventions with strong packages targeted at the relevant school years, a situation which presumably persisted in most control schools. This should have given Unplugged a weak comparator against which what was intended to be a strong package could display its advantages in a study large enough to detect these. What emerged was a pattern of generally positive but modest and usually not statistically significant benefits relative to control schools. It seems probable that Unplugged was indeed preferable to doing nothing very much specifically to prevent substance use. However, if this was the case, the benefits were quite limited.