BACKGROUND AND AIMS: Within many alcohol prevention interventions, changes in alcohol-related attitudes (ARA) are often proposed as precursors to changes in drinking behaviour. This study aimed to measure the longitudinal relationship between ARA and behaviour during the implementation of a large-scale prevention trial. DESIGN AND SETTING: This study was a two-arm school-based clustered randomized controlled trial. A total of 105 schools in Northern Ireland and Scotland participated in the Steps Towards Alcohol Misuse Prevention Programme (STAMPP) Trial. PARTICIPANTS: A sample of 12 738 pupils (50% female
mean age = 12.5 years at baseline) self-completed questionnaires on four occasions (T1-T4). The final data sweep (T4) was 33 months post baseline. MEASUREMENTS: Individual assessments of ARA and heavy episodic drinking (HED) were made at each time-point. Additional covariates included location, school type, school socio-economic status and intervention arm. Estimated models examined the within-individual autoregressive and cross-lagged effects between ARA and HED across the four time-points (Bayes estimator). FINDINGS: All autoregressive effects were statistically significant for both ARA and HED across all time-points. Past ARA predicted future ARA [e.g. ARA CONCLUSIONS: Changes in alcohol-related attitudes were not a precursor to changes in heavy episodic drinking within the Steps Towards Alcohol Misuse Prevention Programme (STAMPP) Trial in Scotland and Northern Ireland. Rather, alcohol-related attitudes were more likely to reflect prior drinking status than predict future status. Heavy episodic drinking status appears to have a greater impact on future alcohol attitudes than attitudes do on future heavy episodic drinking.