Does school ethos explain the relationship between value-added education and teenage substance use? A cohort study

► Contrary to previous studies, high value-added schools were associated with greater substance use prevalence in West Scotland. ► High value-added schools occurred throughout the socio-economic spectrum and ranges of exam results and truancy rates. ► Substance use in Scotland is more likely among disengaged students and those with poorer student-teacher relationships. ► Associations between value-added education and substance use were not mediated by pupils' perceptions of school ethos. ► Scottish schools may influence pupils' substance use through at least two pathways related to school ethos.