Attenuated Doors-Locked P300 Amplitude and Elevated Depressive Symptoms: Effects of Age and Sex in Two Independent Samples of Youth.

Deficits in cognitive and reward-related functions, measured via reductions in the P300 and reward positivity (RewP) event-related potential (ERP) components, are commonly observed in adults suffering with depression. Considering higher risk for depression emerges among females in adolescence, examination of the neurological underpinnings of depression during this critical developmental period can help further elucidate our overall understanding of the etiology of depressive disorders. Therefore, the present study sought to first examine associations between doors-locked P300 amplitude, RewP amplitude, current depression symptoms, and age in an all-female youth sample (sample 1: n = 296; age, 8 to 14). Next, we examined these same associations, as well as sex, in a second independent sample consisting of male and female youths (sample 2: n = 605; age, 11 to 14). Blunted doors-locked P300 was associated with higher depressive symptoms in both samples. Moreover, the association between P300 and depression was stronger among older youths in both samples. Sex further moderated this relationship in sample 2 such that smaller P300 related to greater depression only in females. There were no consistent associations between RewP amplitude and depressive symptoms in either youth sample. These findings suggest that the doors-locked P300 component is a reliable neural correlate of depression in youth that might specifically relate to pathways linked to increased risk for depression among adolescent females.