Abstract
The past 20 years have seen a significant increase in research on the antecedents and consequences of cannabis use in young adults. At the beginning of this period there was a relative paucity of evidence concerning both (i) factors that increased the risk of cannabis use and dependence and (ii) consequences of early and heavy cannabis use on health and adjustment. However, our understanding of these issues has increased dramatically during this period. The current state of knowledge of the effects of cannabis use on health and psychosocial functioning among young people is well summarized in Hall's scholarly review of the evidence 1. Hall attributes this increase in knowledge to the contribution of a series of well?designed epidemiological studies, and in particular the evidence provided by longitudinal birth cohorts during a period of time in which regular cannabis use was relatively common.