Psychological Medicine



Cognitive function in depression: a distinct pattern of frontal impairment in melancholia?


M.-P. AUSTIN a1c1, P. MITCHELL a1, K. WILHELM a1, G. PARKER a1, I. HICKIE a1, H. BRODATY a1, J. CHAN a1, K. EYERS a1, M. MILIC a1 and D. HADZI-PAVLOVIC a1
a1 Mood Disorders Unit, Prince Henry Hospital, Sydney, NSW, Australia

Abstract

Background. Although depressed patients demonstrate impaired performance on a range of neuropsychological tests, there is little research that examines either frontal cognitive deficits or possible differences in test performance between melancholic and non-melancholic subtypes.

Methods. Depressed subjects were administered a broad neuropsychological battery. In an overall analysis, 77 depressed subjects were compared with 28 controls. In a second set of analyses, the depressed sample was divided into melancholic and non-melancholic subsets according to DSM-III-R, the CORE system and the Newcastle scale. These depressed subsets were contrasted to controls and with each other using ANCOVA controlling for age, IQ, simple reaction time and Hamilton Depression scores where appropriate.

Results. The total depressed sample was impaired on most mnemonic tasks, simple reaction time and Trails B. Similar findings applied to DSM-III-R melancholic and non-melancholic subjects. When defined by the CORE and Newcastle (narrower definitions of melancholia), melancholic patients were additionally impaired on WCST (perseverative response) and (for Newcastle) digit symbol substitution. In contrast, the cognitive performance of the CORE and Newcastle-defined non-melancholic patients was largely unimpaired.

Conclusions. Using narrower definitions of melancholia, i.e. CORE and (in particular) Newcastle, melancholic patients were impaired on mnemonic tasks and tasks of selective attention, and set-shifting while non-melancholic subjects were largely unimpaired in their cognitive performance. These differences may be due to impairment of specific neuroanatomical regions in narrowly defined melancholic patients, in particular the anterior cingulate.


Correspondence:
c1 Address for correspondence: Dr M.-P. Austin, Department of Liaison Psychiatry, Prince of Wales Hospital, Randwick, Sydney, NSW 2031, Australia.


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