AN ASSOCIATION BETWEEN A MICROSATELLITE POLYMORPHISM AT THE DRD5 GENEAND THE LIABILITY TO SUBSTANCE-ABUSE - PILOT-STUDY

We have conducted a population-based association study of substance ab use and a microsatellite at the dopamine D5 receptor locus (DRD5) in a sample of European-American males and females with substance dependen ce (SA) or without any psychiatric disorder. Overrepresentation of the most frequent allele (148 bp) was found in males in the SA group (OR = 2.2, P = .02); this finding was reproduced in females (OR = 5.4, p < .001). The difference in the frequencies of this allele between SA ma les and SA females was statistically significant. The genotype coded i n accordance with the dose of this allele correlated with substance ab use liability in males and females (stronger in females) and with nove lty seeking in females. There was no evidence of correlation between t he genotypes of spouses that Could be induced by assortative mating fo r the liability to substance abuse. The data suggest that the DRD5 loc us is involved in the variation and sex dimorphism of substance abuse liability.