Thyrotropin and prolactin response to thyrotropin-releasing hormone in depressed and nondepressed alcoholic men

Thyrotropin-releasing hormone (TRH) stimulation tests were performed on 81 alcoholic men after at least 3 weeks of abstinence. Subjects were given 500 micrograms of TRH intravenously, and thyroid-stimulating hormone (TSH) and prolactin (PRL) were measured at baseline, and then 15 and 30 min later. Comparisons were made among alcoholics with (n = 27) and without (n = 54) a lifetime history of depression as determined by the Diagnostic Interview Schedule. Nine nondepressed, nonalcoholic subjects served as controls. Alcoholics with or without a depression history did not differ from each other or from control in TSH or PRL response area under the curve. Blunted TSH responses were present in 10 (12%) of the alcoholics and none of the controls when blunting was defined as a delta max TSH less than 5 microU/ml. When blunting was defined as a delta max TSH less than 7 microU/ml, 18 (22%) of the alcoholics and 1 (1%) of the controls were blunted. Conversely, 2 (2.5%) of the alcoholics had a delta max TSH greater than 32 microU/ml. All subjects were clinically euthyroid. Contrary to expectation, depressed subjects were slightly less likely to show blunted responses than nondepressed subjects. No relationship was found between neuroendocrine measurements and several measurements of alcoholism or depression. Some alcoholic subjects show a blunted TSH response to TRH injection, which may be a function primarily of the alcoholism itself. The precise mechanism remains unknown.