Electrodermal activity in antidepressant medicated and unmedicated depressive patients and in matched healthy subjects.

A group of 59 depressive in- and outpatients displayed statistically significantly subnormal electrodermal activity (EDA) according to the skin conductance level, the skin conductance response magnitude, the skin conductance response rate, and the index of nonresponding during neutral tone stimulation, compared to 59 mentally and somatically healthy subjects, individually matched for age and sex. Comparisons between 20 antidepressant medicated and 20 unmedicated patients, matched for age, and comparisons between 21 drug-free patients and 10 patients medicated exclusively with antidepressants yielded no statistically significant difference in any EDA variable. However, all the electrodermal central values were somewhat lower in the medicated patients, possibly an effect of greater severity of symptoms. The present and previous findings offer strong support to the hypothesis of a subnormal function of the electrodermal activity in groups of depressive patients.