Doors P300 moderates the relationship between reward positivity and current depression status in adults

Background: Previous research has found deficits in both the reward positivity (RewP) and P300 components of the event-related potential (ERP) in relation to depression. The current study examined whether the P300, elicited from imperative stimuli in a gambling task, relates to depression - and can be utilized in tandem with the RewP to better account for individual differences in depression. Methods: In the current study, 80 adults with current depression (Mage = 39.65, 79% female) and 43 healthy controls (Mage = 37.02, 81% female) completed clinical interviews, self-report questionnaires, and the doors gambling task while EEG was recorded. Results: Results indicated a reduced P300 to doors stimuli (i.e., doors P300) in depression, especially among depressed individuals reporting heightened anhedonia. Gain and loss feedback P300s did not differ between groups. Moreover, the doors P300 moderated the association between RewP and depression status: individuals with relatively intact reward processing (i.e., larger RewP) were more likely to be currently depressed if they exhibited a reduced P300. Limitations: The majority of the sample identified as Caucasian which reduces generalizability of current results. Additionally, the current study is cross sectional design which limits insight into how these ERPs coincide with changes in the disorder. Conclusions: The current study demonstrates that a novel P300 component to the doors stimulus appears to be blunted in currently depressed individuals, and that using the doors P300 in combination with the RewP accounts for significantly more variance in depression.