Growth hormone (GH), blood pressure, and pulse rate responses to clonidine (100-mu-g IV) were studied three times during the first week of alcohol withdrawal in 19 alcohol-dependent patients. Fifteen healthy men were used as controls. The results suggest reduced sensitivity of the alpha-2-adrenoceptors involved in GH secretion for at least 1 week after the end of alcohol intake. In contrast, very short-lasting subsensitivity was found in the alpha-2-adrenoceptors regulating blood pressure.