This study was designed to provide an estimate of the
prevalence of neuropsychological impairment in chronic fatigue
syndrome (CFS), to evaluate the concordance between impairment
found on standardized tests and self-reported
neuropsychological problems, and to study the relationship
between neuropsychological functioning and fatigue severity
and psychological processes. We adopted an individual approach
to determine neuropsychological impairment as contrasted with
the group- comparisons approach used in previous studies.
Also, correction for premorbid functioning and confounders was
done on an individual basis. The results show that a minority
of participants were impaired in neuropsychological
functioning. There was no relationship between
neuropsychological impairment on standardized tests and
self-reported memory and concentration problems.
Neuropsychological functioning was not related to fatigue or
depression. Slowed speed of information processing and motor
speed were related to low levels of physical activity.