The present study was performed in order to establish, with a simple and safe neuroendocrinological test, whether alcoholism is associated with alterations in sensitivity to benzodiazepines. For this purpose, we tested the stimulatory effects of diazepam on GH secretion. An intravenous bolus of 10 mg diazepam was injected in 51 (33-51-year-old) alcoholic men after at least 5 weeks of abstinence and in 20 age- and weight-matched normal controls. On a different occasion, a control test with placebo (physiological saline) was performed in the same subjects. Diazepam but not placebo administration induced a striking increase of GH secretion in the normal controls. In contrast, neither diazepam nor placebo treatment significantly changed the basal serum GH levels in alcoholic men. These data show that alcoholism is associated with disrupted benzodiazepine activity on the hypothalamic-pituitary control of GH secretion. The simplicity of the diazepam GH-releasing test makes the drug suitable for clinical research in alcoholism.