title: An increase in depressive symptoms after myocardial infarction predicts new cardiac events irrespective of depressive symptoms before myocardial infarction.
abstract: BACKGROUND
  Depression after myocardial infarction (MI) is associated with poor cardiovascular prognosis. There is some evidence that specifically depressive episodes that develop after the acute event are associated with poor cardiovascular prognosis. The aim of the present study was to evaluate whether an increase in the number of depressive symptoms after MI is associated with new cardiac events.
  
  
  METHODS
  In 442 depressed and 325 non-depressed MI patients the Composite International Diagnostic Interview interview to assess post-MI depression was extended to evaluate the presence of the ICD-10 depressive symptoms just before and after the MI. The effect of an increase in number of depressive symptoms during the year following MI on new cardiac events up to 2.5 years post-MI was assessed with Cox regression analyses.
  
  
  RESULTS
  Each additional increase of one symptom was significantly associated with a 15% increased risk of new cardiac events, and this was stronger for non-depressed than for depressed patients. This association was independent of baseline cardiac disease severity. There was no interaction with the number of depressive symptoms pre-MI.
  
  
  CONCLUSIONS
  Our findings suggest that an increase in depressive symptoms after MI irrespective of the state of depression pre-MI explains why post-MI depression is associated with poor cardiovascular prognosis. Also increases in depressive symptoms after MI resulting in subthreshold depression should be evaluated as a prognostic marker. Whether potential mechanisms such as cardiac disease severity or inflammation underlie the association remains to be clarified.
authors.affiliation: Department of Psychiatry, University of Groningen, Groningen, the Netherlands. m.zuidersma@med.umcg.nl
authors.forename: M
authors.initials: M
authors.lastname: Zuidersma
authors.forename: J
authors.initials: J
authors.lastname: Ormel
authors.forename: H J
authors.initials: HJ
authors.lastname: Conradi
authors.forename: P
authors.initials: P
authors.lastname: de Jonge
mesh_terms: D000928:Antidepressive Agents / Q000627:therapeutic use; D003863:Depression / Q000188:drug therapy / Q000453:epidemiology* / Q000523:psychology; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D038801:International Classification of Diseases; D007406:Interview, Psychological; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology* / Q000523:psychology; D011379:Prognosis; D011569:Psychiatric Status Rating Scales; D012008:Recurrence
chemical_list: D000928:Antidepressive Agents