Facial and autonomic activity in depression: social context differences during imagery.

Previous research indicates that depressed patients show reduced facial expression as well as a lack of social context differences in frowning in response to sad imagery. The present study examined social context differences in facial electromyogram (EMG), self-reported emotion, skin conductance level and heart rate in 21 depressed and 22 non-depressed women assessed by the Beck Depression Inventory. Subjects were asked to imagine happy and sad situations both with and without visualizing other people. Depressed subjects showed a lack of social context differences in EMG-brow activity during sad imagery while heart rate was increased during sad-social compared to sad-solitary imagery. In contrast, non-depressed subjects showed increased EMG-brow activity during sad-social compared to sad-solitary imagery but no social context differences in heart rate. EMG-cheek activity and heart rate were increased during happy-social compared to happy-solitary imagery in depressed and non-depressed subjects. Skin conductance level was reduced in depressed compared to non-depressed subjects during baseline but failed to respond to imagery. Social context differences in heart rate and a lack thereof of frowning during sad imagery may indicate an altered psychosocial functioning in depression.