title: Clinical analyses of sighted patients with non-24-hour sleep-wake syndrome: a study of 57 consecutively diagnosed cases.
abstract: OBJECTIVE
  The objective of this study was to clarify the clinical features of sighted patients with non-24-hour sleep-wake syndrome.
  
  
  METHODS
  Clinical analyses of consecutive patients suffering from non-24-hour sleep-wake syndrome.
  
  
  METHODS
  The sleep disorders clinic at Kohnodai Hospital, National Center of Neurology and Psychiatry, Japan.
  
  
  METHODS
  Fifty-seven patients who were diagnosed consecutively as having non-24-hour sleep-wake syndrome between 1991 and 2001 were included in the study.
  
  
  RESULTS
  The clinical features and sleep characteristics of the patients were analyzed. A semistructured psychiatric interview that included the criteria for Axis I or II disorders of Diagnostic and Statistical Manual of Mental Disorders, Third Edition-Revised was conducted, and relationships between psychiatric problems and non-24-hour sleep-wake syndrome were analyzed. The patient cohort included 41 (72%) men and 16 (28%) women. The onset of non-24-hour sleep-wake syndrome had occurred during the teenage years in 63% of the cohort, and the mean ( +/-SD) period of the sleep-wake cycle was 24.9 +/- 0.4 hours (range 24.4-26.5 hours). The mean sleep length of the patients was 9.3 +/- 1.3 hours, and 44% of them had a sleep length of between 9 and 10 hours. Psychiatric disorders had preceded the onset of non-24-hour sleep-wake syndrome in 16 patients (28%); of the remaining 41 patients, 14 (34%) developed major depression after the onset of non-24-hour sleep-wake syndrome.
  
  
  CONCLUSIONS
  These results represent the first detailed clinical review of a relatively large number of sighted patients with non-24-hour sleep-wake syndrome.
authors.affiliation: Department of Psychiatry, Kohnodai Hospital, National Center of Neurology and Psychiatry, Kohnodai, Ichikawa, Japan.
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Hayakawa
authors.forename: Makoto
authors.initials: M
authors.lastname: Uchiyama
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kamei
authors.forename: Kayo
authors.initials: K
authors.lastname: Shibui
authors.forename: Hirokuni
authors.initials: H
authors.lastname: Tagaya
authors.forename: Takashi
authors.initials: T
authors.lastname: Asada
authors.forename: Masako
authors.initials: M
authors.lastname: Okawa
authors.forename: Jujiro
authors.initials: J
authors.lastname: Urata
authors.forename: Kiyohisa
authors.initials: K
authors.lastname: Takahashi
mesh_terms: D000328:Adult; D001008:Anxiety Disorders / Q000175:diagnosis / Q000453:epidemiology; D002940:Circadian Rhythm; D015331:Cohort Studies; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000175:diagnosis / Q000453:epidemiology; D007406:Interview, Psychological; D008297:Male; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis / Q000453:epidemiology; D015995:Prevalence; D012017:Referral and Consultation; D012559:Schizophrenia / Q000175:diagnosis / Q000453:epidemiology; D012720:Severity of Illness Index; D020178:Sleep Disorders, Circadian Rhythm / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*