Young and middle-aged depressed women are twice more likely to suffer from heart attacks or premature deaths as compared to those who are not sad, according to an Emory University study.

Researchers said that doctors should be aware of the link as depression puts adults at an increased risk of developing heart problems. They also said that underlying depression could explain lower survival rates among women aged 55 years and younger as compared to men.

"Women in this age group are also more likely to have depression, so this may be one of the "hidden" risk factors that can help explain why women die at a disproportionately higher rate than men after a heart attack," said Dr Amit Shah, study author and assistant professor of Epidemiology, in a press release.

For the study, the researchers examined depression symptoms in 3,237 patients with known or suspected heart disease scheduled for coronary angiography. One-third of the participants were women of an average age of 62 years.

After a follow-up of three years, researchers found that women aged 55 years and younger were 2.17 times more likely to suffer a heart attack, premature death or require artery-opening procedures if they were moderately or severely depressed. For every one-point increase in symptoms of depression among younger women, there was a seven percent increase in heart disease incidents.

On the other hand, symptoms of depression were not linked to heart disease among men and older women.

"Depression itself is a reason to take action, but knowing that it is associated with an increased risk of heart disease and death should motivate people to seek help. Providers need to ask more questions. They need to be aware that young women are especially vulnerable to depression, and that depression may increase the risk to their heart," Shah said in a press release.

Dr Viola Vaccarino, senior author of the study, said that the risks of depression and heart problems in younger women had been well-studied.

"Although the risks and benefits of routine screening for depression are still unclear, our study suggests that young women may benefit for special consideration," Vaccarino said.

The finding is published in the Journal of the American Heart Association.