Error-monitoring in major depression 1 Running head: ERROR-MONITORING IN MAJOR DEPRESSION Electrical brain imaging reveals the expression and timing of altered error monitoring functions in major depression

Major depressive disorder (MDD) is characterized by disturbances in affect, motivation, and cognitive control processes, including error detection. However, the expression and timing of the impairments during error monitoring remain unclear in MDD. Accordingly, the behavior and event-related brain responses (ERPs) of 20 patients with MDD were compared to those of 20 healthy controls (HCs), while they performed a Go/noGo task. Errors during this task were associated with two ERP components, the error-related negativity (ERN/Ne) and the error positivity (Pe). Results show that the ERN/Ne-correct-related negativity (CRN) amplitude difference was significantly larger in MDD patients (after controlling for speed), compared to HCs, while MDD patients exhibited overactive medial frontal cortex (MFC) activation. By comparison, the subsequent Pe component was smaller in MDD patients compared to HCs and this effect was accompanied by a reduced activation of ventral anterior cingulate cortex (ACC) regions. These results suggest that MDD has multiple cascade effects on early error monitoring brain mechanisms.