title: Rates and predictors of remission, recurrence and conversion to bipolar disorder after the first lifetime episode of depression--a prospective 5-year follow-up study.
abstract: BACKGROUND
  In depression, non-remission, recurrence of depressive episodes after remission and conversion to bipolar disorder are crucial determinants of poor outcome. The present study aimed to determine the cumulative incidences and clinical predictors of these long-term outcomes after the first lifetime episode of depression.
  
  
  METHODS
  A total of 301 in- or out-patients aged 18-70 years with a validated diagnosis of a single depressive episode were assessed from 2005 to 2007. At 5 years of follow-up, 262 patients were reassessed by means of the life chart method and diagnostic interviews from 2011 to 2013. Cumulative incidences and the influence of clinical variables on the rates of remission, recurrence and conversion to bipolar disorder, respectively, were estimated by survival analysis techniques.
  
  
  RESULTS
  Within 5 years, 83.3% obtained remission, 31.5% experienced recurrence of depression and 8.6% converted to bipolar disorder (6.3% within the first 2 years). Non-remission increased with younger age, co-morbid anxiety and suicidal ideations. Recurrence increased with severity and treatment resistance of the first depression, and conversion to bipolar disorder with treatment resistance, a family history of affective disorder and co-morbid alcohol or drug abuse.
  
  
  CONCLUSIONS
  The identified clinical characteristics of the first lifetime episode of depression should guide patients and clinicians for long-term individualized tailored treatment.
authors.affiliation: Psychiatric Centre Copenhagen,Research Unit for Affective Disorders,Department O,Rigshospitalet,Copenhagen,Denmark.
authors.forename: J D
authors.initials: JD
authors.lastname: Bukh
authors.affiliation: Department of Biostatistics,University of Copenhagen,Copenhagen,Denmark.
authors.forename: P K
authors.initials: PK
authors.lastname: Andersen
authors.affiliation: Psychiatric Centre Copenhagen,Research Unit for Affective Disorders,Department O,Rigshospitalet,Copenhagen,Denmark.
authors.forename: L V
authors.initials: LV
authors.lastname: Kessing
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001007:Anxiety / Q000150:complications; D001714:Bipolar Disorder / Q000453:epidemiology*; D015897:Comorbidity; D003863:Depression / Q000150:complications / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007297:Inpatients / Q000523:psychology; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010045:Outpatients / Q000523:psychology; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D012008:Recurrence; D012074:Remission Induction; D012720:Severity of Illness Index; D059020:Suicidal Ideation; D055815:Young Adult
keywords: Conversion to bipolar disorder; course of illness; depression; recurrence; remission