[Epidemiology of sleep disorders].

Epidemiological investigations on subjectively reported sleep disturbance suggest an average prevalence of 26.2%. About 12.8% of the general population suffer from moderate to severe sleep disturbance. With a narrow definition, a prevalence of disorders of initiating and maintaining sleep associated with daytime sleepiness of 1.6% was found. Female gender and increasing age are risk factors for sleep disturbances. Psychological stress and psychiatric symptoms, especially anxiety and depressive disorders, are associated with sleep disturbances.