Researchers in England, Finland, France, and the U.S. examined data from about 6,000 middle-aged adults from the British Whitehall II study, which is investigating the effect of social and economic factors on long-term health.
About 14.9% of the study participants scored high on a test designed to determine whether they were depressed.
Study Links Depression to Cardiac Death
Researchers found that:
- Patients with coronary heart disease alone were 67% more likely to die of any cause.
- People who were depressed but otherwise healthy were twice as likely to die as patients who were neither depressed nor had heart disease.
But patients who were both depressed and had heart disease were almost five times as likely to die as people who were mentally and physically healthy.
However, after adjusting for age, sex, and other factors, the combination of depression and heart disease tripled the risk of death from all causes and quadrupled the risk of death from a stroke or heart attack, the researchers write.
More Research Needed to Pinpoint Reasons
Researchers say the biological reasons for the impact of depression on death risk are not clear but possibly involve the stimulation of the body’s inflammatory system and clot formation process.
What is more, depression may alter cellular responses or the metabolism of blood fats, study researcher Hermann Nabi, PhD, of the French National Institute of Health and Medical Research at Hospital Paul Brousse, tells WebMD in an email.
He and the other authors write that their findings stress “the need for healthcare professionals to pay more attention to depression in their cardiac patients.”
“This study provides evidence that depressive symptoms are associated with an increased risk of all-cause and cardiovascular death and that this risk is particularly marked in depressive participants” with diagnosed heart disease, the researchers write.
The findings “stress the importance of developing interventions that are effective in reducing mortality due to depression.”
The study is published online in the medical journal Heart.