A new research suggests that the depression and heart disease combo is far more lethal than having either of these conditions in isolation.
Previous research has indicated that people, who are depressed, but otherwise healthy, are more likely to develop coronary heart disease, irrespective of what other risk factors they might have.
The authors have concluded their findings on just under 6,000 middle aged adults, whose mental and physical health were tracked for an average of five and a half years.
Around one in seven of the 6,000 (14.9%) scored highly on a depressive symptom scale. And one in five (20%) of those with established heart disease were depressed compared with one in seven (14%) of those without heart problems.
During the five and a half year monitoring period, 170 people died. Heart attack or stroke accounted for 47 of these deaths.
Those with coronary heart disease alone were 67% more likely to die of all causes, while those who were depressed, but otherwise healthy, were twice as likely to do so as those who had neither condition.
But those who were both depressed and had heart disease were almost five times as likely to die as their mentally and physically healthy peers.
After taking account of age and sex, and other relevant influential factors, the combination of depression and heart disease tripled the risk of death from all causes and quadrupled the risk of dying from a heart attack or a stroke.
The results emphasized the need for healthcare professionals to pay more attention to depression in their cardiac patients in the study.
The research has been published online in Heart Journal.