Dopamine D2-receptor gene polymorphisms in Scandinavian chronic alcoholics.

Alterations in the dopamine system have been hypothesized as a predisposing factor in alcoholism. The presence of the TaqI A1 and B1 alleles adjacent to the dopamine D 2-receptor gene (DRD2) was studied in Scandinavian alcoholic inpatients (n = 74), alcoholics autopsied at a forensic clinic (n = 19) and controls (n = 81). There were no significant differences between controls and the alcoholics, but a tendency of increased DRD2 TaqI A1 or B1 allele frequencies in alcoholic groups selected for severity (i.e. severity according to DSM-III-R criteria, early onset or severe medical complications due to alcohol abuse) and decreased frequencies in the corresponding less severe alcoholic group. The present study does not yield evidence for the hypothesis of an association between the DRD2 TaqI A1 or B1 alleles and alcoholism.