We evaluated the effect of DHEA complementary treatment in opiate addicts undergoing detoxification. DHEA (100 mg/day) or placebo was added to the routine medication protocol in a randomized, double blind controlled study. Follow-up for 12 months was conducted. Two separate DHEA-treated subgroups were identified by the Fuzzy clustering method: one showed statistically significant improvement in the severity of withdrawal symptoms, depression and anxiety scores (n=34; p<0.001 for all) and the other subgroup deteriorated in all measures (n=15). DHEA at the end of the detoxification program showed a tendency towards correlation with the duration of abstinence (r=0.6843; p>0.05; n=6), while a negative correlation was obtained with the cortisol level (r=-0.900; p=0.005, n=8). The completion-rate of the DHEA-improved subgroup was greater than in the DHEA-deteriorated subgroup (64.7% vs. 33.3%, respectively). The influence of supplementary DHEA treatment was mostly effective in heroin addicts who had not previously used either cocaine or benzodiazepines and who had experienced only few withdrawal programs.