title: Parasomnia among psychiatric outpatients: a clinical, epidemiologic, cross-sectional study.
abstract: OBJECTIVE
  Epidemiologic studies from general population and clinical case series suggest association of parasomnias with mental illnesses and psychotropic medications. This cross-sectional study aimed at determining the prevalence rate of sleepwalking, sleep-related eating disorder (SRED), rapid eye movement sleep behavior-like disorder (RSBD-like disorder), and sleep-related injury (SRI) and their associated factors in an adult psychiatric outpatient clinic.
  
  
  METHODS
  Subjects aged 18 to 65 years who were attending an outpatient clinic in Hong Kong from May 2006 through June 2006 were included in this cross-sectional study. A 3-phase design was employed, including a structured questionnaire on parasomnias, followed by clinical interviews of both questionnaire-positive and -negative groups, and polysomnography for subjects having active parasomnias in recent 1 year. In addition, the principal psychiatric diagnoses, medical illnesses, and detailed drug history over recent 1 year were retrieved from the computerized records.
  
  
  RESULTS
  Twelve hundred thirty-five subjects completed the phase 1 interview. The estimated prevalence of the lifetime diagnoses of sleepwalking, SRED, SRI, sleep violence, and RSBD-like disorder were 8.5%, 4.0%, 21.0%, 3.6%, and 5.8%, respectively, while the 1-year prevalence of these conditions were 2.9%, 2.4%, 8.8%, 2.5%, and 3.8%, respectively. These conditions were associated with depression and a constellation of sleep disturbances. Specific combinations of psychotropics were found to pose risk in particular parasomnias: sedative antidepressants and nonbenzodiazapine hypnotics in sleepwalking, regular zolpidem and antidepressants in SRED, and selective serotonin reuptake inhibitors in RSBD-like disorder.
  
  
  CONCLUSIONS
  Sleepwalking, SRED, RSBD-like disorder, and SRI were common and underrecognized among the psychiatric population in this study. Their occurrences were likely contributed by interacting effect of mental illnesses, sleep disturbances, and specific psychotropic medications. Further prospective study is warranted for clarification of the etiology and clinical management of these potentially dangerous and "hidden" parasomnias.
authors.affiliation: Department of Psychiatry, Shatin Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong SAR.
authors.forename: Siu P
authors.initials: SP
authors.lastname: Lam
authors.forename: Samson Y Y
authors.initials: SY
authors.lastname: Fong
authors.forename: Crover K W
authors.initials: CK
authors.lastname: Ho
authors.forename: Mandy W M
authors.initials: MW
authors.lastname: Yu
authors.forename: Yun K
authors.initials: YK
authors.lastname: Wing
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000553:Ambulatory Care / Q000706:statistics & numerical data; D015897:Comorbidity; D003430:Cross-Sectional Studies; D004347:Drug Interactions; D005260:Female; D006306:Health Surveys; D006723:Hong Kong; D006801:Humans; D015994:Incidence; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology* / Q000523:psychology; D008875:Middle Aged; D020447:Parasomnias / Q000139:chemically induced / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D017286:Polysomnography; D011619:Psychotropic Drugs / Q000009:adverse effects / Q000627:therapeutic use; D012307:Risk Factors; D055815:Young Adult
chemical_list: D011619:Psychotropic Drugs