[Clinical aspects of sleep disorders--experiences with 817 patients of an ambulatory sleep clinic; comment].

Between 1992, the year in which the Sleep Out-Patient Clinic at the Department of Psychiatry, University of Vienna, Allgemeines Krankenhaus (General Hospital) Vienna, was established, and 1996, 817 patients (58% females, average age 52 years; 42% males, average age 48 years) were treated for sleep disorder. According to the International Statistical Classification of Diseases and Related Health Problems (ICD-10) of the World Health Organization (WHO), 70% of the patients presented with a non-organic sleep disorder and 30% with an organic sleep disorder as main diagnosis. Non-organic insomnia was by far the most frequently diagnosed sleep disorder (48%), while within the organic sleep disorders sleep apnea was dominant (12%). In regard to the additional non-organic (mental disorder) diagnoses rounding off the clinical picture, neurotic, stress related, and somatoform disorders were the most common (41%), followed by affective disorders (31%) and mental and behavioural disorders due to intake of psychoactive substances, e.g. alcohol, drugs (15%). Additional organic diagnoses related to sleep disorders involved primarily endocrine disorders such as adipositas (23%), followed by cardiovascular disorders (19%), and primary snoring (17%). The sleep out-patient clinic has at its disposal a supportive diagnostic armamentarium such as all-night sleep polysomnography, 24-hour polysomnography, the Multiple Sleep Latency Test, EEG and EEG-mapping in the affiliated sleep laboratory, the evaluation of event-related potentials (P300) and actometry in the psychophysiological laboratory, as well as psychological and psychophysiological tests in the clinical psychodiagnostic laboratory, in order to determine the right treatment or preventive measures for the individual patients.