title: [Insomnia].
abstract: BACKGROUND
  Insomnia is the most prevalent sleep disorder. Chronic insomnia affects about 10% of the adult population.
  
  
  METHODS
  This review is based on the authors' experience, as well as articles identified through non-systematic searches in Pubmed.
  
  
  RESULTS
  Insomnia is characterized by problems with falling asleep, difficulty maintaining sleep, waking up to early and/or poor sleep quality. The diagnosis implies that the problem causes some type of daytime impairment. Insomnia is divided into several different subtypes. Recent studies indicate that insomnia is an independent risk factor for sick leave and disability pension. Non-pharmacological treatment, i.e. stimulus control and sleep restriction yields better outcome than hypnotics, particularly on a long-term basis.
  
  
  CONCLUSIONS
  Insomnia is highly prevalent, and non-pharmacological therapy is the best documented treatment.
authors.affiliation: Institutt for samfunnsmedisinske fag Universitetet i Bergen, Postboks 7804, 5020 Bergen og Nasjonalt kompetansesenter for søvnsykdommer, Haukeland universitetssykehus, Bergen, Norway. bjorn.bjorvatn@isf.uib.no
authors.forename: Bjørn
authors.initials: B
authors.lastname: Bjorvatn
authors.forename: Børge
authors.initials: B
authors.lastname: Sivertsen
authors.forename: Nicolas
authors.initials: N
authors.lastname: Øyane
authors.forename: Inger Hilde
authors.initials: IH
authors.lastname: Nordhus
authors.forename: Ståle
authors.initials: S
authors.lastname: Pallesen
mesh_terms: D000328:Adult; D006801:Humans; D001523:Mental Disorders / Q000209:etiology; D011788:Quality of Life; D012307:Risk Factors; D018582:Sick Leave; D007319:Sleep Initiation and Maintenance Disorders / Q000145:classification / Q000150:complications / Q000175:diagnosis / Q000628:therapy