What's the link between depression and heart disease?
Depression and loneliness put a terrible strain on the heart, and not just in the emotional sense: Psychological distress can turn a survivor of heart disease into a victim. Consider the words of physician Dean Ornish in his book Love and Survival: The Scientific Basis for the Healing Power of Intimacy. "Among heart patients, depression is as good a predictor of imminent death as smoking, obesity, or a previous heart attack," he says. "Study after study shows that people who are lonely, depressed, and isolated are three to five times more likely to die prematurely than people who feel connection in their life."
Here are a few studies that back up Dr. Ornish's point. Researchers in France looked at nearly 6,000 men and women found that those who were depressed and had heart disease had at least a three times higher risk of dying early than those who were neither depressed nor had heart disease. Researchers at the Montreal Heart Institute tracked 222 heart attack survivors and found that those suffering from depression were roughly six times more likely than others to die within six months of their attack. The researchers later found that depression also led to an eight-fold increase in death rates 18 months after a heart attack.
Loneliness takes a similar toll. In a Duke University Medical Center study of 1,400 men and women with at least one severely blocked artery, the unmarried patients without close friends were three times more likely than the others to die over the next five years.
Depression may even help heart disease get its start. Several studies have suggested that depressed people who are otherwise healthy are more likely to develop heart disease than peers who aren't depressed. For example, a 13-year study of 1,500 subjects conducted at Johns Hopkins University found that an episode of depression increased the risk of a heart attack more than four-fold. These studies take smoking and other factors into account, providing strong evidence that depression alone is enough to cut down a once-healthy heart.
Women may be at particular risk, according to a study supported by the National Heart, Lung, and Blood Institute. After studying more than 6,000 men and women over a period of six years, researchers concluded that women who suffered depression were more likely to have risk factors for heart disease. Specifically, the study found that depressed women were twice as likely to have "metabolic syndrome" -- a condition in which at least three of five known risk factors for heart disease are present. Depressed men in the study didn't show any increase in metabolic syndrome.
Finally, a study from the Centers for Disease Control and Prevention found that severe depression and anxiety could more than double the risk of developing hypertension, a major contributor to heart disease.
Why is depression so hard on the heart?
Doctors don't know exactly why the blues appear to be so dangerous, but it's clear that depression affects the heart in numerous ways. Some research into the connection is straight forward and shows that depression leads to poor health behaviors like not exercising, which in turn leads to a higher risk of heart disease. Other research shows no difference in physical activity levels in depressed patients, but does show a connection between depression and increased belly fat -- which suggests a biological link. One large study published in the Journal of the American College of Cardiology shows that people who are mentally distressed have higher levels of C-reactive protein, a substance in the body that increases with the risk of heart disease. Some experts speculate that depression tends to smooth out the normal ups and downs in heart rate, a sign that the organ may be weaker and less flexible. And for unknown reasons, mental distress seems to encourage blood cells called platelets to clump together, possibly setting the stage for artery-clogging blood clots.
Can depression treatments fight heart disease?
If you suffer from heart disease, easing your mind just might prolong your life. A study from Duke University Medical Center found that a stress-management program cut the chances that a heart patient would suffer a heart attack or need surgery by 74 percent. And while nobody knows if anti-depressants can help fight heart disease, there's reason to be optimistic. A psychiatrist at Emory University School of Medicine has found that giving the antidepressant paroxetine to heart attack survivors made their platelets less "sticky" and reduced their risks of blood clots. Although antidepressant use has been linked in different studies to both increased and decreased heart problems, sertraline and citalopram are safe and effective for depressed patients with coronary heart disease, according to the American Heart Association.
National Institute of Mental Health 5600 Fishers Lane Rockville, MD 20857 Phone: (800) 421-4211
National Foundation for Depressive Illness, Inc. P.O. Box 2257 New York, NY 10016 Phone: (800) 826-3632
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