Lack of association between dopamine D1 and D2 receptor genes and bipolar affective disorder.

Fifty-six patients with bipolar affective disorder and 69 healthy control subjects were tested for association of restriction fragment length polymorphism alleles at the dopamine D1 and D2 receptor loci. No significant associations were found; thus, the hypothesis that a single mutant form of either receptor gene is responsible for the phenotype of patients with bipolar affective disorder was not supported.