Affective Processing in Depression Risk: Insights From Event-Related Potentials

A mechanism that might be implicated in the etiopathogenesis of depression is a blunted activation of the Positive and Negative Valence Systems, leading to a reduced elaboration of emotional stimuli. Yet, relatively little attention has been devoted to disentangling the distinct temporal phases that constitute this process, namely, emotional anticipation and emotional stimulus processing. Hence, the primary aim of the present study was to investigate distinct phases of emotional responses as potential psychophysiological correlates of vulnerability to depression. Data was collected from young adults with a high vulnerability to depression, which was determined by the presence of a family history of the condition but no current symptoms (n = 23, 19 F), or the presence of subclinical depressive symptoms (n = 39, 25 F), and 30 (19 F) controls with neither a family history nor current symptoms. Participants performed an S1-S2 task, in which an emotional picture (pleasant, neutral, unpleasant) (S2) was anticipated by a cue (S1) that predicted its valence. During the task, the electroencephalogram was recorded. Emotional anticipation was indexed by the Cue-P300, whereas emotional elaboration was indexed by the late positive potential (LPP) at three processing windows (300-600, 600-1000, 1000-2000 ms). Both vulnerability groups showed reduced Cue-P300 for pleasant and unpleasant cues relative to controls, indicating diminished preparatory allocation of attentional resources to upcoming emotional events. During image processing, both at-risk groups exhibited reduced initial motivated attention (i.e., LPP amplitude in 300-600 ms time window) to pleasant, but not unpleasant, stimuli compared to controls, whereas no between-group differences emerged in later LPP time windows. These findings suggest that depression vulnerability is characterized by broadly blunted emotional anticipation and a selective reduction in motivated attention to pleasant stimuli.