Background: We investigated whether depressive disorder and Type D personality refer to different forms of distress in the Myocardial INfarction and Depression - Intervention Trial (MIND-IT).
Method: A total of 1205 myocardial infarction (MI) patients were screened at 3, 6, 9 and 12 months post-MI; those with a Beck Depression Inventory (BDI) score 10 underwent the World Health Organization (WHO) Composite International Diagnostic Interview (CIDI). Patients completed the DS14 measure of Type D personality at 12 months and were stratified to one of four subgroups: depressed/Type D, depressed/non-Type D, non-depressed/Type D, or non-distressed.
Results: Two hundred and six (17%) patients were diagnosed with depression and 224 (19%) with Type D. Only 7% (n=90) had both forms of distress, and 60% of Type D patients were free of depression in the first year post-MI. Type D moderated the relationship between depressive and cardiac disorder. Depressed patients without Type D had the worst clinical status (left ventricular dysfunction, heart failure, Killip class 2) as compared to other patients, whereas depressed patients with a Type D personality did not differ in clinical status from non-distressed patients. Contrasting 'pure' Type D and depression subgroups showed that Type D patients without depression were less likely to have left ventricular dysfunction [odds ratio (OR) 0.47, 95% confidence interval (CI) 0.35-0.65, p<0.0001] than depressed patients without Type D.
Conclusions: Depression and Type D refer to different forms of distress in post-MI patients; most Type D patients display non-psychiatric levels of distress and Type D moderates the relationship between depressive and cardiac disorder. Different depression/Type D subgroups may be involved in the prediction of cardiac prognosis.