title: The impact of depression heterogeneity on inhibitory control.
abstract: OBJECTIVE
  Major depressive disorder (MDD) is associated with deficits in executive cognitive function, including inhibitory control. However, inconsistencies have been found across studies. Depression is a heterogeneous disorder and these inconsistencies may therefore relate to heterogeneity in relatively small samples.
  
  
  METHODS
  Here we sought to examine event-related potentials (ERPs) during a cognitive Go/No-Go task in melancholic (n = 60) and non-melancholic depressed patients (n = 54) relative to controls (n = 114).
  
  
  RESULTS
  Behavioural responses indicate that inhibitory control processes are differentially affected by subtypes of depression such that melancholic patients exhibit a greater number of commission errors and more variable response rates in comparison to non-melancholic patients and controls respectively. However, ERPs do not differ during a cognitive Go/No-Go task when ERPs associated with correct responses are examined.
  
  
  CONCLUSIONS
  These findings indicate that while patients with melancholia differ from patients without melancholia and controls, no neurophysiological differences are observed when controlling for observable behavioural impairment.
authors.affiliation: Discipline of Psychiatry, Sydney Medical School, University of Sydney, Australia.
authors.forename: Candice R
authors.initials: CR
authors.lastname: Quinn
authors.forename: Anthony
authors.initials: A
authors.lastname: Harris
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Kemp
mesh_terms: D000328:Adult; D001007:Anxiety / Q000150:complications / Q000503:physiopathology / Q000523:psychology; D058256:Brain Waves / Q000502:physiology; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology*; D018913:Event-Related Potentials, P300 / Q000502:physiology; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology