Depression Remission Over Six Months Characterized by Elevated Target-Locked P300 ERP Component: Prospective Evidence Employing an Affective Visual Oddball Task.

Depression is a mental health disorder characterized by dysfunction in cognitive and motivational neural systems. Event-related potential (ERP) research has explored these issues and has found that depression is associated with a reduced P300 ERP component, which likely reflects deficits in processes related to attentional allocation, decision-making, and context updating. However, most of the extant research has employed cross-sectional designs, limiting insight into the temporal precedence between the P300 and depression. Prospective investigations of the P300 and depression association are scarce and would provide further insight into the etiopathology of depression. The present study sought to examine the relationship between baseline P300 amplitude, elicited from an affective visual oddball paradigm, and depression remission after 6 months in a sample of adults (n = 48) suffering from current depressive disorders. Findings indicated that a larger P300 amplitude to target stimuli at baseline was associated with depression remission at the six-month follow-up visit, while no differences were observed for P300 components elicited by the distractor or standard stimuli. The present findings suggest that a reduced P300 amplitude to imperative stimuli may indicate a trait-like neural vulnerability of cognitive and motivational deficits contributing to a greater risk of relapse and a more chronic course of depression. Trial Registration: NCT01941862.