© 2003 Canadian Medical Association or its licensors

Over the past decade, evidence has accumulated tosuggest that depression may be a risk factor for car-diac mortality in patients with established coronary artery disease (CAD), as well as in previously healthy individ-uals. The authors of several excellent review papers have con-cluded that the evidence supporting the impact of depression is strong.1–3 Most published, prospective studies have docu-mented a marked association between different measures of depression and objective cardiac outcomes in patients with different clinical presentations of CAD, and usually this link has been demonstrated to be independent of traditional car-diac risk factors. Some recent studies have reported a dose–response relation between severity of depression symp-toms and prognosis.4–6 Also, there are plausible biological mechanisms that could account for the association.7 Further investigation is needed to evaluate the possibility that depres-sion may be caused by vascular disease of the brain (the vascu