title: Predisposing factors in delayed sleep phase syndrome.
abstract: We classified 64 patients with chronic delayed sleep phase syndrome (DSPS) into the primary (n = 53) and secondary (n = 11) group according to presence or absence of such signs as difficulty in waking up which appeared much earlier than the onset of DSPS. The age at the onset of the early signs concentrated in adolescence. The familial occurrence of DSPS was noted in 11 patients of the primary group. In human leukocyte antigen (HLA) typing, the incidence of DR1 positivity alone was significantly higher in DSPS patients than in healthy subjects. Minnesota Multiphasic Personality Inventory revealed high scores on depression, psychoasthenia and hypochondriasis. We suggest that a predisposition to DSPS includes biological, genetic, social and psychological factors, various combinations of which may lead to DSPS.
authors.affiliation: Sleep Disorders Clinic, Seiwa Hospital, Neuropsychiatric Research Institute, University of Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Takahashi
authors.forename: H
authors.initials: H
authors.lastname: Hohjoh
authors.forename: K
authors.initials: K
authors.lastname: Matsuura
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D015798:HLA-DR1 Antigen / Q000235:genetics; D006801:Humans; D008950:MMPI; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D020178:Sleep Disorders, Circadian Rhythm / Q000175:diagnosis / Q000209:etiology* / Q000235:genetics; D013001:Somatoform Disorders / Q000175:diagnosis
chemical_list: D015798:HLA-DR1 Antigen