initiation will not reduce levels of adult alcohol problems, though it may still confer other benefits in relation to adolescent harms.2 Within the research community there has been debate about whether there is an underlying causal relationship between earlier AFD and alcohol problems in adulthood, and opinion has been divided on this issue.6 8 9 Obvious importance to policy and practice makes imperative evaluation of the research evidence to ascertain the strength of any associations and the likelihood of causation. Here we conduct a systematic review of cohort studies to examine the association between AFD and adult alcohol problems and consider the evidence for a causal relationship.
