title: Sleep problems and hospitalization for self-harm: a 15-year follow-up of 9,000 Norwegian adolescents. The Young-HUNT Study.
abstract: OBJECTIVE
  To investigate the association between sleeping problems in adolescence and subsequent hospital admission for self-harm (SH).
  
  
  METHODS
  Prospective cohort study, linking health survey information on sleep problems to hospital-based patient records.
  
  
  METHODS
  Residents of Nord-Trøndelag County, Norway, aged 13-19 years in 1995-97.
  
  
  METHODS
  10,202 adolescents were invited to participate in the Young-HUNT study; 8,983 (88%) completed the health survey.
  
  
  RESULTS
  10% of participants reported difficulties initiating sleep, 4% reported early morning wakening. Ninety-eight participants (27% male) were hospitalized following SH over a mean 12 years follow-up. Difficulties initiating sleep/early morning wakening were associated with increased risk of SH (HR 2.11, 95% CI 1.29-3.46, sex- and age-adjusted) compared with no problems, yet coexistent symptoms of combined anxiety/depression explained most of the association with sleep problems (fully adjusted HR 1.19, 95% CI 0.66-2.16). The HR of combined difficulties initiating sleep/early morning wakening differed in those with and without anxiety/depression at baseline (P interaction = 0.03); among those without caseness symptoms of anxiety/depression it was 5.58 (95% CI 2.02-15.40), while in those with caseness symptoms of anxiety/ depression it was 0.82 (95% CI 0.19-3.44).
  
  
  CONCLUSIONS
  Sleep problems are common among Norwegian adolescents. The strong association between sleep problems and subsequent hospitalization for self-harm could mainly be related to coexistent symptoms of anxiety and depression. Prevention of adolescent sleep problems, anxiety and depression should be targeted when seeking to reduce and prevent self-harm.
authors.affiliation: Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Asbjørn
authors.initials: A
authors.lastname: Junker
authors.affiliation: Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway ; Forensic Department and Research Centre Brøset, St. Olavs University Hospital, Trondheim, Norway.
authors.forename: Johan Håkon
authors.initials: JH
authors.lastname: Bjørngaard
authors.affiliation: School of Social and Community Medicine, Bristol University, Bristol, UK.
authors.forename: David
authors.initials: D
authors.lastname: Gunnell
authors.affiliation: Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway ; Faculty of Health Sciences, Nord-Trøndelag University College (HiNT), Levanger, Norway.
authors.forename: Ottar
authors.initials: O
authors.lastname: Bjerkeset
mesh_terms: D000293:Adolescent; D001007:Anxiety / Q000150:complications / Q000453:epidemiology; D015331:Cohort Studies; D003863:Depression / Q000150:complications / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006306:Health Surveys; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D009664:Norway / Q000453:epidemiology; D011446:Prospective Studies; D012306:Risk; D016728:Self-Injurious Behavior / Q000150:complications* / Q000453:epidemiology*; D012893:Sleep Wake Disorders / Q000453:epidemiology* / Q000523:psychology*; D055815:Young Adult
keywords: Difficulties initiating sleep; adolescents; anxiety and depression; cohort study; early morning wakening; self-harm