title: The impact of depression heterogeneity on cognitive control in major depressive disorder.
abstract: OBJECTIVE
  Depressed patients display a variety of deficits in neuropsychological function, and contradictory findings in the literature may be due to disorder heterogeneity. The aim of this study was to examine the impact of severity, subtype and symptoms on cognitive control.
  
  
  METHODS
  Neuropsychological function across a range of cognitive control tasks was examined in melancholic (n = 65) and non-melancholic depressed patients (n = 59) relative to controls (n = 124). The relationship between subtype (melancholia vs non-melancholia) and anxiety was also examined.
  
  
  RESULTS
  Melancholia was characterised by attention and working memory deficits typically associated with the dorsolateral prefrontal cortex, while non-melancholia was characterised by verbal memory recall deficits indicative of left frontal lobe and medial temporal lobe function. The severity of anxious arousal and psychomotor disturbance contributed to cognitive impairment more than the severity of depression symptoms and anxious apprehension.
  
  
  CONCLUSIONS
  Findings highlight a differential impact of depression subtype and severity, and suggest that anxious arousal and psychomotor disturbance may contribute to poorer performance on neuropsychological tasks associated with dorsolateral prefrontal cortex function.
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: Kim
authors.initials: K
authors.lastname: Felmingham
authors.forename: Philip
authors.initials: P
authors.lastname: Boyce
authors.forename: Andrew
authors.initials: A
authors.lastname: Kemp
mesh_terms: D000328:Adult; D001007:Anxiety / Q000453:epidemiology; D001288:Attention; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000209:etiology*; D003865:Major Depressive Disorder / Q000145:classification / Q000150:complications* / Q000453:epidemiology; D056344:Executive Function; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term; D008875:Middle Aged; D009483:Neuropsychological Tests