SUNDAY, June 20, 2004 (HealthDayNews) -- A growing body of research suggests that state of mind -- not clogged arteries or high blood pressure -- is a big risk factor for heart disease among older women.
Mildly and moderately depressed women are estimated to be 50 percent more likely to die of heart attacks than other women, research shows. Meanwhile, scientists and doctors are trying to untangle the connection between the two illnesses.
"There's got to be a physiological link, and people are trying to look at it," said Sylvia Wassertheil-Smoller, a professor of epidemiology and population health at the Albert Einstein School of Medicine in New York City.
But the chicken-and-egg question remains: Which comes first, depression or heart disease?
In a recent study, Wassertheil-Smoller and her colleagues examined the medical records of 93,676 postmenopausal women aged 50 to 79. The study, which followed the subjects for an average of four years, was the first of its kind to track women over time, instead of looking backward by studying them after they had had heart attacks, she said.
The women were healthy when the research began, and those suffering from untreated severe depression did not participate. Fifteen percent of the women were eventually diagnosed with depression, with symptoms most common in those aged 50 to 59. Symptoms dropped by ages 70 to 79.
"Maybe by the time you're getting to be 70 to 79, you're accepting life and it doesn't get you down so much," Wassertheil-Smoller said.
Although their symptoms were mild or moderate -- perhaps due to help from antidepressants -- the depressed women were 50 percent more likely to die of a heart attack and 30 percent more likely to die of other causes.
What's more, death rates were higher for the depressed women, regardless of whether they smoked or were overweight.
The researchers based their findings on results from the Women's Health Initiative, the largest study of U.S. women's health ever undertaken. They appeared in a recent issue of the Archives of Internal Medicine.
Wassertheil-Smoller isn't sure why depression may contribute to heart disease. Depression might boost levels of dangerous inflammation in the body, or it may disrupt the blood's ability to clot properly, she said.
It's also possible that depression could be an early warning sign, a kind of "sentinel symptom" that appears before heart disease becomes obvious, she said.
For now, she suggests that doctors pay attention to signs of depression in older women, especially when they're not connected to an event such as the loss of a spouse. Doctors also need to follow up with depressed patients, just as they would schedule future appointments to check on a patient who reported a high cholesterol level, she said.
Dr. Francine Welty, director of cardiovascular care for women at Beth Israel Deaconess Medical Center in Boston, agreed that doctors need to pay more attention to the mental health of their patients. She added that women may become depressed or take less care of themselves when they're alone.
"A lot of my older female patients with heart disease no longer have their spouse or they may be divorced, have little family support," she said.
According to Welty, exercise can be a good antidote to both depression and heart disease in women. "No matter what their age, they need to get out there and do aerobic exercise. Walking is sufficient," she said. "Studies have shown that walking is as beneficial as other exercise."
Walking can also help combat depression by virtue of the fact that it's an enjoyable activity, she said. "If you get outside and it's a nice, sunny day and you go on a walk, you'll feel better."
The American Psychological Association has more information on women and depression.