An international team of researchers have identified certain genetic factors that might explain why individuals with heart disease are prone to suffer from depression.
The team from The Miriam Hospital, The Montréal Heart Institute, University of Montréal and McGill University has discovered certain genes related to vascular system that might help predict depression in individuals with heart disease.
"Depression can significantly impact quality of life for heart disease patients and can increase the risk for additional cardiac events or even death," said lead author Dr Jeanne M. McCaffery, of The Miriam Hospital's Weight Control and Diabetes Research Centre.
"Although it's too early to begin to speculate about the possible clinical implications of these findings, it's intriguing to think that there may be a genetic explanation as to why people with heart disease are more susceptible to depression," she added.
Previous studies have shown that approximately 15 to 20 percent of heart disease patients experience depression, with the highest rates seen among those who recently experienced a cardiac event.
In the study involving 977 heart patients, the researchers looked at 59 different candidate genes because of their relevance to a biological pathway of interest or their prior association with depression in medical literature.
The genes include those related to inflammation; platelet aggregation, or clumping; endothelial function involving the cells that line the inner surface of blood vessels; and omega-3 fatty acid metabolism, which can affect the hardening of the arteries.
They discovered that genetic variations involving endothelial dysfunction - a hallmark for vascular diseases, such as atherosclerosis - and platelet aggregation appear to contribute to depressive symptoms.
"Although further study is needed, our findings suggest that endothelial dysfunction may be a novel mechanism contributing to depressive symptoms among heart disease patients," said McCaffery, who is also an assistant professor of psychiatry and human behavior at The Warren Alpert Medical School of Brown University.
The study is published in American Journal of Medical Genetics Part B: Neuropsychiatric Genetics.