Current genetic and biological approaches to alcoholism.

Three out of 4 adoption and 2 out of 3 twin studies imply a genetic contribution to alcoholism in males. A recent study of moderate drinking in male twins suggests that familial factors account for some two-thirds of the variance in alcohol consumption, and that the genetic component slightly outweighs the effects of the within family culture. There has been little support for the notion of a genetic entity which expresses itself as alcoholism in males and depressive illness in females, but among normal male twins anxiety and depression are genetically correlated with alcohol consumption. Increased liability to form acetaldehyde and the potentially additive tetrahydroisoquinolines could be one factor predisposing to alcoholism but human studies have been less convincing than their animal counterparts.