Mean manganese superoxide dismutase (Mn-SOD) concentrations in the serum of patients suffering from alcohol dependence is almost twice as high as in serum of non-dependent controls. In order to investigate the time course of this parameter during abstinence, we determined it at different time points. Patients had mean Mn-SOD serum concentrations (+/-S.D.) of 150.4 +/- 76.3, 121.1 +/- 40.7, 94.6 +/- 37.8 micrograms/ml at 1, 10 and 40 days after abstinence compared to 76.3 +/- 16.9 micrograms/ml as mean Mn-SOD value in the control group. Although the Mn-SOD concentration tended to normalise during abstinence, the differences between index and control group remained significant up to the last measurement at day 40.