Cognitive, Behavioural and Social Determinants of Prolonged Fatigue and Chronic Fatigue Syndrome

Abstract

Background: The objective of the study was (1) to compare patients diagnosed with Chronic Fatigue Syndrome (CFS) to a (gender and age) matched sample of people suffering from prolonged fatigue (PF) with respect to fatigue severity, somatic complaints, psychological distress, physical functioning and use of health care resources, and (2) to examine to what extent cognitive, behavioral and social factors contributed to fatigue severity and physical functioning in each group. Methods: Sample size was 192 for each group (mean age = 40; 88% were female). Data were collected with self-report questionnaires; the study was a case-control cross-sectional study. Findings: The two groups differed from each other on each of the dimensions except psychological distress. For both groups, illness perceptions were the strongest determinants of fatigue and physical functioning. Activity avoidance contributed to fatigue severity in PF, whereas all-or-nothing behaviour contributed to fatigue severity in CFS. Adequate social support was associated with less fatigue in CFS only. Activity avoidance was associated with worse physical functioning in both groups. Discussion: Our findings suggest that activity avoidance leads to the development of chronic fatigue and ultimately CFS, whereas all-or-nothing behaviour maintains CFS.