Studies of late have found associations between depression and heart disease.
Those who suffer from a mood disorder, for instance, may be twice as likely to have a heart attack compared to individuals who are not depressed, according to recent data.
But the relationship between depression and heart disease has been poorly understood.
A new study may help to clarify the link, suggesting that depressed people also suffer from a dysfunctional biological stress system. In it, researchers found depressed individuals have a slower recovery time after exercise compared to those who are non-depressed.
Cardiovascular disease is the number one cause of death in the United States, accounting for more that 28 percent of annual deaths, making the association with depression a life or death matter.
“There have been two competing theories as to why depression is linked to cardiovascular disease,” said first author Jennifer Gordon, a doctoral candidate at McGill University.
“Depressed people may have poorer health behaviors, which may in turn lead to heart problems. The other possibility is physiological: a problem with the stress system known as the fight or flight response. Our study was the first to examine the role of a dysfunctional fight or flight response in depression in a large population.”
In the study, 886 participants with an average age of 60 years old, were followed. Approximately 5 per cent of participants were diagnosed with a major depressive disorder.
All individuals were asked to undergo a stress test after which their heart rate and blood pressure were recorded. Recovery heart rates and blood pressure levels were compared between depressed and non-depressed individuals.
“We found that it took longer for the heart rate of depressed individuals to return to normal,” said senior author Simon Bacon, Ph.D.
“Heart rate recovery from exercise is one way to measure the fight or flight stress response. The delayed ability to establish a normal heart rate in the depressed individuals indicates a dysfunctional stress response. We believe that this dysfunction can contribute to their increased risk for heart disease.”
Published in the journal Psychophysiology, the research warns of the importance of testing for cardiovascular disease among people suffering from major depression.
“The take-home message of this study is that health care professionals should not only address the mental disorder, but also the potential for heart disease in patients who are suffering from major depression,” said Bacon. “Both of these health issues should be treated to minimize risk of severe consequences.”
Source: Concordia University