Study: How depression increases risk of heart attack
Depression is linked to higher risk of heart disease and recent data shows people suffering from mood disorders may have double the risk of heart attack compared to people who are not depressed.
Now researchers have more information about how that happens that goes beyond the theory that depressed people engage in poor health behaviors.
A new investigation suggests depression and heart disease have a biological link that was previously poorly understood.
First author of the study, Jennifer Gordon, who is a PhD candidate at McGill University explains “There have been two competing theories as to why depression is linked to cardiovascular disease. 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.”
The study, conducted by Concordia and the Montreal Heart Institute, McGill University, the Hôpital Sacré-Coeur de Montréal, the Université du Québec à Montréal and the University of Calgary enrolled 886 participants whose average age was 60.
The participants underwent stress tests that measured heart rate and blood pressure. Approximately five percent suffered from major depressive disorder. The researchers compared heart rate recovery and blood pressures between depressed participants and those without depression.
Simon Bacon, a professor in the Concordia University Department of Exercise Science and a researcher at the Montreal Heart Institute explains “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.”
The study found heart rates of people suffering from depression took longer to return to baseline normal.
Bacon says the finding shows patients with depression should also be treated for potential heart disease. Patients with depression may be twice as likely to have a heart attack, from a dysfunctional 'fight or flight' stress response. The results are published in the journal Psychophysiology.
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