Sleep disorders in patients with chronic fatigue.

This prospective, cohort study examined the prevalence of sleep disorders among highly selected patients with chronic fatigue. On the basis of responses suggestive of sleep pathology on a screening questionnaire, 59 patients from a university-based clinic for chronic fatigue who had undergone a medical and psychiatric evaluation underwent polysomnography. Criteria for chronic fatigue syndrome (CFS) were met by 64% of patients and those for a current psychiatric disorder were met by 41%. Overall, 41% of patients had abnormal results for a multiple sleep latency test and 81% had at least one sleep disorder, most frequently sleep apnea (44%) and idiopathic hypersomnia (12%). In comparing patients who did and did not meet CFS criteria, no significant differences were found in individual sleep symptoms or sleep disorders. Likewise, symptoms and sleep disorders were unrelated to psychiatric diagnoses. In conclusion, chronically fatigued patients with suggestive symptoms may have potentially treatable coexisting sleep disorders that are not associated with meeting criteria for CFS or a current psychiatric disorder.