Does Depression Predict Physical Function in Coronary Artery Disease, or Vice Versa?

Depression is associated strongly with the onset, course, and outcome of coronary artery disease (CAD), but temporal relations are unclear. German investigators explored the specific association of depression and physical function in 883 patients who underwent coronary artery bypass graft surgery. Depression and physical function were assessed with structured questionnaires 1 to 3 days before surgery and at 2 months and 1 year after surgery.

The prevalence of major depression was 8.5% at baseline; during follow-up, depressive symptoms declined and physical function improved. Path analysis (a technique to examine whether an association between two variables could be causal) showed a reasonably strong relation between presence of depression an…