What’s the correlation between the occasional or regular use of cannabis by adolescents and its progression to nicotine dependence, harmful alcohol use and use of other illicit drugs in young adulthood? What impact could the wider availability of cannabis have on this advance? Complex questions that Michelle Taylor (Senior Research Associate in Epidemiology, School of Social and Community Medicine, Bristol. UK) answers in this podcast. The interview, inspired by a study published in the Journal of Epidemiology and Community Health, is conducted by the editor of the journal, Jim Dunn. Dr Taylor also talks about the differences in gender and possible policy implications of her group’s findings. Read the details of the study “Patterns of cannabis-use during adolescence and their association with harmful substance use behaviour: Findings from a UK birth cohort” in the JECH website: http://jech.bmj.com/content/early/2017/05/17/jech-2016-208503.