Functional Incapacity and Physical and Psychological Symptoms: How They Interconnect in Chronic Fatigue Syndrome

Background: It has been argued that perceived functional incapacity
might be a primary characteristic of chronic fatigue syndrome (
CFS) and could be explained by physical symptoms. If so, it could
be expected to be closely associated with physical, but not
psychological symptoms. The study tests this hypothesis. Sampling
and Methods: The sample consisted of 73 patients, with a diagnosis
of CFS according to the Oxford criteria, randomly selected from
clinics in the Departments of Immunology and Psychiatry at St.
Bartholomew's Hospital, London. The degree of fatigue experienced
by patients was assessed using the Chalder Fatigue Questionnaire
and a visual analogue scale. Self-rated instruments were used to
measure physical and social functioning, quality of life, and
physical and psychological symptoms. Results: Principal-component
analysis of all scale scores revealed 2 distinct components,
explaining 53% of the total variance. One component was
characterized by psychological symptoms and generic quality of life
indicators, whilst the other component was made up of physical
symptoms, social and physical functioning and indicators of
fatigue. Conclusions: The findings suggest that perceived
functional incapacity is a primary characteristic of CFS, which is
manifested and/or explained by physical symptoms. Copyright (C)
2008 S. Karger AG, Basel