The error processing system in major depressive disorder: cortical phenotypal marker hypothesis.

Major depressive disorder (MDD) ensues reduced goal-directed cognition and behaviour. Cognitive and emotional flexibility to disengage and adapt future responses was examined in the error processing system (error-related negativity/ERN, error-positivity/Pe event-related potentials) of 58 depressed patients (21 current, 37 remitted) vs. 27 controls undergoing cognitive and affective Go/NoGo paradigms. ERN was equivalent between patient and controls for the cognitive task, albeit amplitude attenuated in patients during the affective task. Blunted ERN amplitudes were evident between patients and controls in males compared to females, plausibly underpinned by disparities in dopaminergic pathways. Patients displayed enhanced Pe amplitudes for both cognitive and affective tasks. Abberations in cortical error processing in MDD appear specific to affective systems for the pre-attentive ERN, opposed to cognitive and affective processing for the consciously-integrated Pe. Heightened Pe, observed in both current and remitted patients, advocates the possibility of the Pe waveform as a candidate intermediate phenotype of depression.