Depression: avoidance learning and physiological correlates in clinical and analog populations

The behavioral and physiological components of depression were investigated in two experiments comparing eight student and seven non-student depressed females with an equal number of students and non-student controls on avoidance tasks and electrodermal responsivity to an aversive audiotape. Avoidance behavior was assessed in both active and passive paradigms where the correct response or response suppression, respectively, function to avoid a noxious buzzer. Physiological activity and reactivity were compared using measurements of skin resistance level and SRR fluctuations during resting and aversive tape periods. It was found that the depressed groups showed inferior active and superior passive avoidance learning as compared to controls. Depressed subjects were also more emotionally responsive (showed a greater number of SRR) during presentation of the audiotape. A passive avoidance model for depression is suggested for the explanation of the phenomena observed. A distinct difference was also found between student and non-student populations. The utility of college student analogs for depression is questioned.