title: The prevalence of mixed episodes during the course of illness in bipolar disorder.
abstract: OBJECTIVE
  To investigate the prevalence of mixed episodes during the course of illness in bipolar disorder.
  
  
  METHODS
  A total of 1620 patients with an ICD-10 diagnosis of bipolar affective disorder at the first psychiatric contact were identified in a period from 1994 to 2003 in Denmark and the prevalence of mixed, depressive and hypomanic/manic episodes were calculated at each episode.
  
  
  RESULTS
  The prevalence of mixed episodes increased from the first episode to the tenth episode, however, only for women (6.7% of the first episodes leading to psychiatric care compared with 18.2% of the tenth episodes). For men, the prevalence of mixed episodes was constantly low. At all episodes, the presence of a current mixed episode increased the risk substantially of getting a future mixed episode.
  
  
  CONCLUSIONS
  Clinicians should pay more attention to mixed episodes, especially among women, as they may represent an increasing treatment challenge as the illness progress.
authors.affiliation: Department of Psychiatry, University of Copenhagen, Rigshospitalet, Denmark. lars.kessing@rh.dk
authors.forename: L V
authors.initials: LV
authors.lastname: Kessing
mesh_terms: D000328:Adult; D000437:Alcoholism / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D001714:Bipolar Disorder / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003718:Denmark; D018450:Disease Progression; D005260:Female; D006801:Humans; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012042:Registries; D012737:Sex Factors; D019966:Substance-Related Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology