Affective startle modulation in clinical depression: Preliminary findings

Background: Modulation of the startle reflex by affective foreground stimul i was investigated in a group receiving inpatient treatment for major depre ssive episodes (n = 14) and an age and gender matched nondepressed group (n = 14). Methods: Participants viewed 27 pleasant, neutral, and unpleasant pictures chosen from the International Affective Picture System. Acoustic startle pr obes were presented during picture viewing and participants also rated the affective qualities of the pictures. Results: While ratings of the pictures were largely similar between the dep ressed and nondepressed groups, they displayed dissimilar patterns of start le modulation. In the nondepressed group, blinks elicited during unpleasant pictures were significantly larger than during pleasant pictures, whereas the depressed group failed to show this effect. Analyses which separated th e depressed participants into moderate and severe groups based on Beck Depr ession Inventory scores, revealed that while the moderately depressed group also showed a normal pattern of startle modulation, the severely depressed showed potentiated startles during the pleasant pictures. Conclusions: These preliminary results suggest that severely depressed pati ents may respond to some pleasant stimuli as if they are aversive, possibly because such stimuli are seen as signals of frustrative nonreward. Biol Ps ychiatry 1999;46:542-550 (C); 1999 Society of Biological Psychiatry.