Without specific etiology or effective treatment, Chronic fatigue syndrome (CFS) remains a contentious diagnosis. Individuals with CFS complain of fatigue and poor sleep - symptoms that are often attributed to psychological disturbance. To assess the nature and prevalence of sleep disturbance in CFS and to investigate the widely presumed presence of psychological maladjustment we examined sleep quality, sleep disorders, physical health, and daytime sleepiness, fatigue, and psychological adjustment in three samples: individuals with CFS, a healthy control group, and individuals with a definite...