A new Gallup poll finds that Americans who experience heart attacks are twice as likely to have been diagnosed with depression — 30.1 percent vs. 15 percent. In addition, twice as many heart attack survivors (16.5 percent) report being currently treated  for depression when compared to people who've never had a heart attack (8.1 percent).
 

The figures are derived from interviews with 164,102 Americans who participated in the Gallup-Healthways Well-Being Index. Of that total, 6,236 had suffered at least one heart attack.
 

The Gallup poll isn't the first report to link heart attack and depression. Last year, a study conducted at Emory University and published in the Journal of the American Heart Association found that women 55 and younger were twice as likely to have a heart attack or to require an artery-opening procedure if they were depressed.
 

A study at Loyola University Medical Center found that people with major depression had much higher levels of an inflammatory biomarker associated with cardiovascular disease — interleukin-6 — than healthy controls. Researcher Dr. Angelos Halaris said that 40 to 60 percent of heart patients have clinical depression, and 30 to 50 percent of depressed patients are at risk of cardiovascular disease.
 

Researchers have also linked depression with mortality.

A study at the Montreal Heart Institute found that depressed patients were six times more likely to die within six months after having a heart attack than heart patients who didn't have depression.
 

The link between heart attack and depression emphasizes the importance of the psychological facets of living with an illness, and that patients need to have strong support networks and make positive changes in their lifestyles, say researchers.