Psychiatric illness in patients with chronic fatigue and those with rheumatoid arthritis

To identify psychiatric differences between patients with chronic fatigue and those with rheumatoid arthritis and to investigate whether patients meeting Centers for Disease Control (CDC) criteria for chronic fatigue syndrome (CFS) can be differentiated from patients with chronic fatigue on measures of disability and psychosocial distress.

Cross-sectional study comparing 98 patients with chronic fatigue with 31 patients with rheumatoid arthritis on structured psychiatric interviews and patient questionnaires. Nineteen patients meeting CDC criteria for CFS were compared with 79 patients with chronic fatigue not meeting CDC criteria on questionnaires measuring disability and psychosocial distress.

Consecutive patients with chronic fatigue were selected from a chronic fatigue clinic at the University of Washington, and 31 consecutive patients with rheumatoid arthritis were sampled from a private rheumatology practice.

Patients with chronic fatigue had a significantly higher prevalence of lifetime major depression and somatization disorder than did patients with rheumatoid arthritis. Patients with chronic fatigue also had a significantly higher prevalence of current and lifetime psychiatric diagnoses. Only 19 of 98 patients with chronic fatigue met CDC criteria for CFS. Patients meeting CDC criteria for CFS could not be differentiated from the larger group of patients with chronic fatigue on any study variable.

Patients with chronic fatigue have a significantly higher burden of psychiatric illness than do patients with rheumatoid arthritis. The psychiatric illness preceded the development of chronic fatigue in over half the patients. Centers for Disease Control criteria for CFS did not select a subset of chronic fatigue patients who could be differentiated on disability or psychosocial parameters from patients with chronic fatigue who did not meet CDC criteria.