Electrophysiological evidence for reduced inhibitory control in depressed patients in partial remission: a Go/Nogo...

Major depressive disorder (MDD) can be characterized by a wide-ranging profile of cognitive deficits including attention, memory, and executive functions which is possibly due to reduced volumes and a hypometabolism of the anterior cingulate cortex, orbitofrontal, and dorsolateral prefrontal cortex. We examined 21 patients with MDD in partial remission and 21 age-, sex-, and education matched healthy controls using event-related potentials (ERPs). Participants performed a hybrid flanker Go/Nogo task while multichannel EEG was recorded. Two ERP components were of interest which repeatedly have been linked to response inhibition: the Nogo-N2 and the Nogo-P3 which can be observed in Nogo trials of a Go/Nogo task. MDD patients showed a specifically reduced Nogo-P3 while the Nogo-N2 and the P3b in Go trials were unaffected. These results provide further evidence of impaired response monitoring and control processes in patients with MDD.