Cognitive deficits in patients with chronic fatigue syndrome compared to those with major depressive disorder and healthy controls.
OBJECTIVE
Chronic fatigue syndrome (CFS) patients report usually cognitive complaints. They also have frequently comorbid depression that can be considered a possible explanation for their cognitive dysfunction. We evaluated the cognitive performance of patients with CFS in comparison with a control group of healthy volunteers and a group of patients with MDD.


METHODS
Twenty-five patients with CFS, 25 patients with major depressive disorder (MDD), and 25 healthy control subjects were given standardized tests of attention, working memory, and verbal and visual episodic memory, and were also tested for effects related to lack of effort/simulation, suggestibility, and fatigue.


RESULTS
Patients with CFS had slower phasic alertness, and also had impaired working, visual and verbal episodic memory compared to controls. They were, however, no more sensitive than the other groups to suggestibility or to fatigue induced during the cognitive session. Cognitive impairments in MDD patients were strongly associated with depression and subjective fatigue; in patients with CFS, there was a weaker correlation between cognition and depression (and no correlation with fatigue).


CONCLUSIONS
This study confirms the presence of an objective impairment in attention and memory in patients with CFS but with good mobilization of effort and without exaggerated suggestibility.
Department of Psychiatry, Université Catholique de Louvain, 1200 Brussels, Belgium. Eric.Constant@uclouvain.be
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Constant
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Adam
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Gillain
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Lambert
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Masquelier
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Seron
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D003072:Cognition Disorders / Q000209:etiology / Q000523:psychology*; D003865:Major Depressive Disorder / Q000150:complications / Q000523:psychology*; D004522:Educational Status; D015673:Fatigue Syndrome, Chronic / Q000150:complications / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009042:Motivation; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time; D013404:Suggestion; D011795:Surveys and Questionnaires; D055815:Young Adult