Associations of type-D personality and depression with somatic health in myocardial infarction patients

Objective: Depression and type-D, personality have both been associated with worse cardiac prognosis in myocardial infarction (MI) patients. There is some debate, however, that the association between depression and cardiac prognosis is confounded by somatic health. We therefore compared to what extent depression and type-D personality are associated with somatic health. Method: We studied the association of depressive disorder and type-D with baseline somatic health in a subsample of 1205 post-MI patients from the Myocardial Infarction and Depression Intervention Trial study. Depressive disorder was assessed according to ICD-10 criteria with the Composite International Diagnostic Interview during the post-MI year and type-D with the DS14 at I-year follow-up. Somatic health was operationalized by baseline LVEF, Charlson Comorbidity Index, previous MI, and CABG or PTCA during hospital admission. Results: Prevalence rates were 17.1% for post-MI depression and 18.7% for type-D. After controlling for potential confounders, post-MI depression was associated with poorer baseline LVEF [odds ratio (OR)=3.17, 95% confidence interval (Cl)=2.28-4.41] and greater comorbidity (OR=1.46, 95% CI=1.02-2.09), whereas type-D personality was not (LVEF: OR=1.31, 95% CI=0.93-1.87; comorbidity: OR=0.92, 95% CI=0.63-1.35). Conclusion: Post-MI depression during the post-MI year is more related to somatic health than type-D personality at 12 months post-MI and, specifically, somatic symptoms of depression. Confounding of cardiovascular effects of psychological distress by poor somatic health status is thus more likely to occur in post-MI depression than in type-D personality. (c) 2007 Elsevier Inc. All rights reserved.