Depression following myocardial infarction (MI) can be a first-ever episode for some, whereas for others, it may represent a recurrent episode or one that was present at the onset of the infarction. We investigated if there are differences in pre- and post-MI characteristics between these subtypes.

Four hundred sixty-eight patients admitted for an MI were assessed for the presence of an ICD-10 depressive disorder following MI. A comparison was made between first-ever and ongoing or recurrent depression on demographic and cardiac data, personality, and depression characteristics.

Depressive disorder during the first post-MI year was present in 25.4% of the MI patients (n=119), and almost half were ongoing or recurrent (n=53, 44.5%). Recurrent and ongoing depression was related to high neuroticism (Z=2.77, P<.01), whereas first-ever depression was associated with MI severity (poor left ventricular ejection fraction: Z=1.64, P=.05; PTCA or CABG during hospitalization: Z=1.88, P=.03; arrhythmic events: Z=1.49, P=.06).

Our results suggest that in the first-ever post-MI depression cases, depression may be triggered by the severity of the MI, whereas ongoing and recurrent depression is more related to personality. Future research should address the question whether these subtypes of depression differ in cardiovascular prognosis and response to psychiatric treatment.