Depression at any point in life tied to heart risk

By Amy Norton

NEW YORK (Reuters Health) - Older adults who've suffered a bout of major depression at any time in their lives appear to face an elevated risk of heart disease, new research suggests.

In a study of more than 10,000 U.S. adults ages 60 or older, researchers found that those who ever had an episode of major depression were more than twice as likely as those without such a history to have coronary heart disease.

The link remained when the researchers accounted for other factors related to mental health and heart health -- such as obesity, smoking, drug use and high blood pressure.

The findings, published in the journal Psychosomatic Medicine, add to a body of evidence tying depression to an increased risk of heart disease.

In contrast to many past studies, though, the investigators looked at lifetime depression, rather than only recent depression, explained Dr. Nancy M. Petry of the University of Connecticut School of Medicine in Farmington, the senior researcher on the work. They also looked at diagnoses of clinical depression, rather than simply symptoms suggestive of depression, Petry told Reuters Health.

For people with a history of major depression, Petry said, the findings suggest that early and regular check-ups for their heart health might be wise. Managing other heart risk factors -- by lowering blood pressure, quitting smoking or making diet and exercise changes, for example -- may help counter the heightened risk.

The findings are based on data from a national health survey of 10,573 older U.S. adults. Participants completed a standard questionnaire used to diagnose major depression and certain other mood disorders.

Men and women with a single lifetime episode of major depression had a risk of heart disease comparable to that of participants who'd suffered multiple bouts of depression, a "noteworthy" finding, according to Petry.

Experts suspect that depression may affect heart disease risk through direct physiological effects. For example, research suggests that depression boosts the activity of platelets, cells that promote blood clotting. It may also have effects on the immune system or the sympathetic and parasympathetic nervous systems, which help regulate the heart's response to everyday stresses.

Depression may also affect heart health in indirect ways. People with depression may, for instance, be less likely to make healthy lifestyle choices, or to stick with treatments for heart risk factors like high blood pressure.

SOURCE: Psychosomatic Medicine, October 2007.