In the six-year study of nearly 4,500 people aged 65 and older who were free of heart disease when the study began, those who said they felt depressed most often were 40% more likely to develop heart disease than those who reported feeling down least often. The findings appear in Circulation: Journal of the American Heart Association.
Common symptoms of depression may include feeling scared, lonely and/or irritable, having difficulty concentrating, and experiencing sleep problems. Statistics show that as many as 30% of people 65 and older are depressed, yet only 1% receive treatment.
Just how depression can raise the risk of heart disease is unclear, but there are several theories. For example, depressed people may be less likely to take care of themselves and more likely to engage in unhealthy behaviors such as smoking and leading a sedentary life — both of which are known to increase heart-disease risk. Or depression may increase mental stress, which, in turn, encourages blockage of the blood vessels, the study authors speculate.
The new findings join others that link heart disease and depression, including a study published in July in Archives of Internal Medicine that found men with clinical depression were more than twice as likely to develop heart disease as their nondepressed counterparts.
To arrive at their findings, the researchers in the current study, led by Curt Furberg, MD, PhD, a professor of public health science at Wake Forest University in Winston-Salem, N.C., used a standard scale to measure depression among their study participants.
Overall, women reported having more symptoms of depression than men, and married people or those who lived with others were less likely to report feeling down. Smokers, sedentary people, and those who were overweight were more likely to report being depressed, Furberg and colleagues note.
“This study has established that symptoms of depression are an independent risk factor for … heart disease in older individuals,” Furberg says. “This doesn’t mean that depressive symptoms are a cause of … heart disease, but that the presence of depressive symptoms predicts the development of disease.”
Whether being treated for depression could lower risk a person’s risk of getting heart disease remains to be seen. “We have shown an association, but the next step is whether treatment will stave off or slow the progression of heart disease,” he says.
Martha Hill, RN, PhD, a professor of nursing at Johns Hopkins University in Baltimore and past president of the American Heart Association, tells WebMD that the new findings are a wake-up call for patients, family members, and doctors to look for signs of depression. “I think we have to go look for depression and ask about it, [because] we know that much depression in primary care goes unrecognized, and even when recognized, it goes untreated,” she says.
Approximately 19 million Americans suffer from depression. Even though 80% of people who seek help will get relief from medication, therapy, or a combination of the two, just one in three people actually gets treatment, according to the National Institute of Mental Health, in Bethesda, Md.
“If you are the child of elderly parents, look for signs of depression and if you see them, talk to your parents and make sure you [tell] it to their primary care providers,” she says, adding that there are many health benefits to treating depression.
Calling the new findings “a valuable addition,” James Muller, MD, director of clinical research in cardiology at Massachusetts General Hospital and Harvard Medical School, says that “this study fits into the larger context of other studies.”
Muller and colleagues have found that psychological factors, such as anger and/or bereavement, can trigger a heart attack. He says that while more study is needed to determine how treating depression might affect the prevention of heart disease, it’s still a good idea.
“Setting aside the [heart] risk, depression should be treated in and of itself. It’s a miserable condition and there is lots of good therapy for it,” he tells WebMD.
For more information from WebMD, visit our Diseases and Conditions Center on Depression.