1. Basal cortisol levels were significantly lower in 4 week abstinent alcoholics (n=11;group A) than in normal controls (n=9;- group C), whereas no significant difference was found between alcoholics abstinent greater than 1 year (n=9; group B) and controls. 2. In all groups, dexamethasone induced a similar decrease in circulating cortisol concentrations. Computed tomographic examinations showed a significantly higher ventricular-brain ratio VBR) and wider 3rd ventricle width in group A than in group B; no significant differences were observed between groups B and C. 3. In contrast, the number of cerebral sulci was similar in all groups. A negative relationship was found between neuroradiological findings and basal cortisol values in group A, but not in groups B and C. The neuropsychological tests showed worse scores in group A than in the other groups. 4. These findings show subcortical damages and reduced cortisol levels in alcoholics after 4 weeks of abstnence. These alterations appear to be at least in part reversible after a long period of abstinence.