to addiction. Whether the availability of alcohol/drug, particularly in adolescence, is sufficient to promote onset of disease or whether later stress exposure, perhaps resulting in drinking to cope, is a requirement remains to be determined. Clearly, it is important to have longitudinal studies, starting in early-childhood, that look at the effect of cumulative stress. As it is generally accepted that the genetic risk of AUDs and DD is likely to derive from numerous genes, each with small to moderate effects, the number of potential G×E interactions is large, therefore G×E interactive effects are not likely to contribute to a major part of the variance. Finally, important phenotypes with relevance for treatment that should be explored in G×E studies are craving and stress-induced relapse.
