Depression in coronary heart disease. What is the appropriate diagnostic threshold?

The purpose of this study was to determine the threshold at which depression becomes important for the daily functioning of patients with heart disease. Data from a 1-year prospective cohort study of health maintenance organization patients undergoing coronary angiography for coronary heart disease were analyzed for differences in a standardized composite measure of functioning. Patients with major depression (N = 19) and patients with minor depression (N = 28) were significantly more functionally impaired at baseline and at 1-year follow-up than those with no depression (N = 110). The major and minor depression groups did not differ significantly. The significance of the depression group differences was reduced, but not eliminated, when controlling for differences in reported heart symptoms.