• Public health

Since the mid-1980s, an impressive body of epidemiological research has examined links between depression and coronary heart disease (CHD). Depression is more common in patients with CHD than in those without heart disease, with ≥20% of hospitalised patients after a myocardial infarction (MI) meeting modified psychiatric criteria for major depressive disorder (MDD).1 While available data suggest that depression rates are lower in patients with stable CHD than in hospitalised patients, depression is still more common than in the general community. Depression is associated with increased chances of developing CHD in apparently healthy subjects. In patients with CHD depression predicts cardiac admissions and death, increased healthcare costs and utilisation of services.2 3 There is evidence of an increased cardiac risk associated with measures of depression symptoms as well as with diagnosed MDD, and of a dose–response relationship between depression severity and prognosis in patients with CHD. Many plausible biological explanations have been suggested. The quantity and strength of the epidemiological data is comparable to that leading to the general acceptance of several other cardiac risk factors. Why, then, is depression not considered a major risk factor? Should it be?