[The neuroendocrine aspects of chronic alcoholism: the effect of alcohol intake and its withdrawal]

Abstract

Neuroendocrine dysfunctions, in part similar to those found in depression, are present in chronic alcoholism. The aim of this investigation was to evaluate the effects of chronic alcohol intake on cortisol secretion in basal conditions, after dexamethasone (DXT) suppression or corticotropin (ACTH) stimulation in 10 alcoholic men, during active drinking and after two weeks of alcohol withdrawal. The 24-hour, day- and night-time urinary cortisol and melatonin levels, and the effects of thyrotropin releasing hormone (TRH) on thyrotropin (TSH) and prolactin (PRL) secretions were studied in the same subjects. The data were correlated to the scores obtained by the Hamilton Rating Scale for depression and compared to those found in healthy subjects. Increased cortisol levels and the lack of DXT suppression of cortisol secretion are considered to be alcohol-dependent inasmuch as they disappear in most patients after alcohol withdrawal. The cortisol response to ACTH 1-24 infusion measured before and after alcohol withdrawal was similar in the patients we studied; moreover no significant difference was found between patients and controls. The increment of urine free cortisol levels in active alcoholics was not statistically significant. Urine cortisol levels became similar to those of the control subjects after alcohol withdrawal. The increased diurnal values of urine melatonin and the inversion of the physiological ratio between nocturnal and diurnal levels observed during alcohol intake became normal upon alcohol withdrawal. The TSH and PRL responses after the administration of 50 or 200 micrograms TRH were higher in alcoholics than in controls, while a blunted response is known to occur in depression.