title: Severity of depressive episodes according to ICD-10: prediction of risk of relapse and suicide.
abstract: BACKGROUND
  The ICD-10 categorisation of severity of depression into mild, moderate and severe depressive episodes has not been validated.
  
  
  OBJECTIVE
  To validate the ICD-10 categorisation of severity of depression by estimating its predictive ability on the course of illness and suicidal outcome.
  
  
  METHODS
  All psychiatric in-patients in Denmark who had received a diagnosis of a single depressive episode at their first discharge between 1994 and 1999 were identified. The risk of relapse and the risk of suicide were compared for patients discharged with an ICD-10 diagnosis of a single mild, moderate or severe depressive episode.
  
  
  RESULTS
  At their first discharge, 1103 patients had an ICD-10 diagnosis of mild depressive episode, 3182 had a diagnosis of moderate depressive episode and 2914 had a diagnosis of severe depressive episode. The risk of relapse and the risk of suicide were significantly different for the three types of depression--increasing from mild to moderate to severe depressive episode.
  
  
  CONCLUSIONS
  The ICD-10 way of grading severity is clinically useful and should be preserved in future versions.
authors.affiliation: Department of Psychiatry, University of Copenhagen, Rigshospitalet, Blegdamsvej 9, DK 2100 Copenhagen Ø, Denmark. lars.kessing@rh.dk
authors.forename: Lars Vedel
authors.initials: LV
authors.lastname: Kessing
mesh_terms: D000328:Adult; D000368:Aged; D003718:Denmark; D003866:Depressive Disorder / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012307:Risk Factors; D012720:Severity of Illness Index; D013405:Suicide; D013997:Time Factors