This article provides a comprehensive and critical review of
the neuropsychological and related literature on chronic
fatigue syndrome (CFS). Despite the methodological limitations
observed in several studies, some consistent findings are
noted. The most consistently documented neuropsychological
impairments are in the areas of complex information processing
speed and efficiency. General intellectual abilities and
higher order cognitive skills are intact. Emotional factors
influence subjective report of cognitive difficulty, whereas
their effect on objective performance remains uncertain.
Although the neuropathological processes underlying cognitive
dysfunction in CFS are not yet known, preliminary evidence
suggests the involvement of cerebral white matter. Directions
for future research are outlined.