Depression and Heart Disease: Link Is Clear

Article excerpt

Despite mounting evidence that major depression is a major risk factor for heart disease, the American Heart Association has thus far refused to add the condition to its list of predisposing factors.

This is a remarkable story. Studies in the literature show an increased risk of depression in patients with ischemic heart disease. Other researchers have found that depression is a risk factor for poorer outcome after a myocardial infarction. In fact, depression is as important a risk factor for development of heart disease as cigarette smoking.

Recent evidence implicates excessive platelet reactivity as a possible physiologic link between depression and heart disease. In another study, researchers found that selective serotonin reuptake inhibitor therapy can reverse many of the depression-specific effects on platelet clotting.

Over more than a decade, researchers have demonstrated that depression raises the risks of morbidity and mortality in patients with various forms of heart disease. The strength of the scientific evidence is so great that it can no longer be ignored--more than 50,000 patients are in the database now linking depression and coronary artery disease.

The screening and treatment of heart disease patients for depression has important health and safety implications for our patients. Despite our efforts, the American Heart Association (AHA) has not agreed to include depression as a risk factor. Researchers have written to the AHA and sent them data on several occasions over the past 5 years, to no avail.

Depression should be a risk factor along with genetics, diabetes, hypertension, thrombocyte dysfunction, hyperlipidemia, smoking, and obesity.

In the National Health Examination study, researchers followed 2,832 participants for 12 years (Epidemiology 1993;4:285-94). The results were quite striking--fatal and nonfatal ischemic heart disease was significantly associated with depressed affect and hopelessness over the follow-up period.

Another study demonstrated almost a sixfold increase in cardiovascular mortality among depressed patients, compared with their nondepressed counterparts (JAMA 1993;270:1819-25). This naturalistic study included 222 patients interviewed 7 days after a myocardial infarction and followed for 6 months. Despite an equal cardiovascular disease burden, depressed patients had a 16.5% adjusted relative risk of heart-related death at 6 months vs. 3% for nondepressed patients. Another follow-up at 18 months found that the risk increased to 20% in the depressed group, compared with 6% in the nondepressed patients (Circulation 1995;91:999-1005).

A higher risk of death was related to severity of depression as measured by the Beck Depression Inventory in another study (Circulation 2002;105:1049-53). …