Suffering from heart disease and depression at the same time can dramatically increase the risk of death, researchers have revealed.
Experts studied the combination of both factors after a previous investigation revealed that individually they can raise the chances of dying from a stroke or heart attack.
But results have shown that suffering from both heart disease and depression creates a higher risk of death, experts writing in the journal Heart said.
The researchers looked at more than 6,000 middle-aged men and women across Britain over a six-year period.
The study was led by researchers from the University of Versailles in France and University College London.
Around one in five of those taking part had both heart disease and depression.
Overall, 170 people died during the study period, including 47 from cardiovascular disease such as heart attacks or strokes.
The results showed that people with heart disease alone had a 67% higher chance of dying from any cause than those without either heart disease or depression.
Meanwhile, people only with depressive symptoms were more than twice as likely to die as those with neither heart disease or depression.
When experts looked at those people with both depression and heart disease, and adjusted the results to take account of factors likely to influence the results such as age and sex, they found the combination tripled the risk of death from any cause and quadrupled the risk of dying from cardiovascular disease.
They said: "A major implication of these results is the need for healthcare professionals to pay more attention to depression in their cardiac patients."