Further neuroendocrine evidence for reduced D2 dopamine receptor function in alcoholism.

D2 dopamine receptor function, as assessed by growth hormone (GH) responses to apomorphine (APO; 0.18-0.24 mg i.v.), was investigated in 15 male alcoholics with reported long-term abstinence. Results from only nine subjects could be evaluated. These subjects had been heavy alcohol consumers for a mean of 15 +/- 10 years and had thereafter been abstinent for a mean of 7 +/- 6 years prior to the investigation. Eight male healthy subjects, all of whom were light social drinkers, were selected as controls. The maximum GH responses to APO were significantly lower in the alcoholics (5.8 +/- 5.8 mU/l) than in the controls (22.1 +/- 19.2 mU/l). This finding gives neuroendocrine evidence for reduced D2 dopamine receptor function in alcoholics with long-term abstinence.