And because none of the elderly people actually had symptoms of heart trouble at the start of the exercise, it is unlikely that heart problems could have sparked the depression.

Complaints are dismissed by GPs who fail to investigate properly and simply tell people they're suffering from a panic attack

MIND

But, according to mental health charity, MIND, there is a real problem with people suffering from depression not being taken seriously by their GPs when they report physical symptoms.

A study by the charity found that one third of people with depression felt that they had been badly treated or misdiagnosed by their GP.

"We find that complaints are dismissed by GPs who fail to investigate properly and simply tell people they're suffering from a panic attack or stress," a spokeswoman said.

Risk exposure

There are several reasons why depression might expose people to more cardiac risk.

Elderly people with these feelings are less likely to take exercise, and more likely to smoke or eat badly.

Mental stress is thought to increase the formation of plaques on the side of blood vessels, which can lead to blocking of vital arteries.

Dr Curt Furberg, who led the study, said: "We have shown an association, but the next step is whether treatment will stave off or slow the progression of heart disease."