Researchers assessed 235 older people diagnosed with depression. The patients were randomly assigned to receive either antidepressants and psychotherapy or standard care determined by their doctor.
Patients who had no evidence of heart disease at the study start who received antidepressants and therapy for their depression almost halved their risk of a heart attack or stroke during the eight years of the study, compared with the standard care group, the researchers found.
"Ultimately, this line of research could produce a new approach to preventing cardiovascular disease," said study author Jesse Stewart, an associate professor of psychology at Indiana University-Purdue University Indianapolis.
Depression a risk factor
Health-care professionals have long known that depression is a risk factor for heart attack and stroke. However, few studies have looked at whether depression treatment can reduce the risk of cardiovascular problems, Stewart noted.
Some studies that have looked at whether treatment can help have found no effects, he said. But he wondered if the timing of the treatment might make a difference.
In his study, the patients enrolled between 1999 and 2001. All were aged 60 or older and diagnosed with depression. In each group, some had existing cardiovascular disease and some did not.
The study was designed to look at the effect of medication and therapy compared to standard care on depression, not heart disease. The researchers took another look at the data to assess the benefits of depression treatment on heart and brain health.
Over the study period, 119 patients had a cardiovascular problem such as a heart attack or stroke.
Of the 168 who had no heart disease at the study's start, those in the group getting therapy and medication were 48% less likely to have a stroke or heart attack than those in the standard care group, the researchers found.
Those who received both medicine and therapy but had heart disease when they enrolled in the study did not have a lower risk of heart attack or stroke than those receiving standard care.
Stewart cautioned that the results are preliminary. The finding did not prove cause and effect, but only an association.
However, depression is linked with physiological changes, such as an increase in inflammation, a known risk factor for heart disease, Stewart noted.
Those who are depressed may also be "more likely to smoke, be less physically active, have a poor diet and be less adherent to medications," Stewart said. Those behaviours could also increase heart attack and stroke risk.
The study was published in Psychosomatic Medicine.
One expert said the findings give doctors valuable information.
The new study explores an additional potential avenue to reduce the risk of heart disease, and that's a plus, said Dr Charles Chambers, an interventional cardiologist at Penn State University College of Medicine, Hershey.
Much attention has already been focused on depression after a heart attack, he said. "Depression is very common in heart attack patients," noted Chambers, the president-elect of the Society for Cardiovascular Angiography and Interventions.
Limitations of the study
One limitation of the study, he said, is that it was designed originally to look at the effects of different treatments on the depression only.
When doctors talk about preventing first heart attacks, Chambers said, they talk about "the big five risk factors – high blood pressure, smoking, diabetes, cholesterol and family history."
However, other issues that boost heart attack and stroke risk should not be overlooked, he noted.
"Sedentary lifestyle, stress and psychosomatic issues such as depression should not be underestimated," Chambers said.