Electrodermal activity in relation to diagnostic subgroups and symptoms of depressive patients.

The electrodermal activity (EDA) in 59 depressive patients was investigated during stimulation with neutral tone stimuli. The patients were classified according to six dichotomies: 1) dysthymic disorder vs major depressive episode (DSM-III); 2) melancholic vs nonmelancholic major depressive episode (DSM-III); 3) endogenous vs nonendogenous (Newcastle scale); 4) high vs low inhibition; 5) psychomotor inhibition vs agitation; and 6) indices of high vs low hypothalamic disturbance. The low EDA usually found in depressive patients seems to be more pronounced in endogenous patients and in patients with symptoms of inhibition. Relationships between indices of hypothalamic dysfunction and low EDA were found, but lacked homogeneity. Early debut and long duration of current depression were related to small magnitude of the skin conductance response.