People who develop depression after being diagnosed with heart disease may be more likely to have a heart attack or die than those without depression, a new study finds.
The study included nearly 23,000 heart patients in the Canadian province of Ontario who were diagnosed with heart disease between late 2008 and late 2013.
During an average follow-up of three years, those with depression were 83 percent more likely die of any cause and 36 percent more likely to have a heart attack than those without depression.
Depression did not affect the chances of needing bypass surgery or heart artery stents.
However, the study did not prove that depression caused an increased risk for heart attack and death in these patients. It only found an association between those factors.
The study will be presented at an American College of Cardiology meeting in Chicago. Research presented at meetings is considered preliminary until published in a peer-reviewed journal.
"Patients who develop depression after being diagnosed with heart disease have a much worse prognosis," said lead researcher Dr Natalie Szpakowski, an internal medicine resident at the University of Toronto.
"Our findings suggest that these patients may need to be screened for mood disorders, whether it's by their family doctor or cardiologist," she said in an American College of Cardiology news release.
The researchers also found that patients with depression were more likely to be women and to have more severe chest pain. Other factors associated with depression included smoking, diabetes and having a higher number of other health problems.
"This is consistent with the literature in that women are more prone to depression, whether it's due to sex hormones or social roles, we don't fully know," Szpakowski said. "Other studies have also found that more severe chest pain has been linked to depression, and we know people with more medical illnesses are more susceptible to being depressed."
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