A large Swedish study published last week reports that men and women hospitalized for depression are about one and a half times as likely as others to develop coronary heart disease. The risk is even greater for people hospitalized before age 50.

The researchers identified 44,826 men and women hospitalized for depression from 1987 to 2001 in Sweden, and then traced their history of heart disease using the Swedish national discharge registry. The study appears in the December issue of The American Journal of Preventive Medicine.

As patients get older, the risk declines, and people ages 70 to 79 at the onset of depression have no increased risk for cardiac illness compared with people in control groups. But those hospitalized for depression from age 25 to 49 were almost three times as likely to suffer heart attacks as those not hospitalized.

The association between severe depression and heart disease held even after accounting for socioeconomic status and geography.

According to Dr. Kristina Sundquist, the senior author and an associate professor of medicine at the Karolinska Institute in Stockholm, this strong association between severe depression and heart disease suggests that treating depression could be a preventive.

"However," she said, "in order to find evidence that successfully treated depression would make the risk for heart disease decrease, other types of studies are needed, such as randomized controlled studies."

Dr. Sundquist said she doubted that such a study could be ethically undertaken because it would require a control group of untreated patients.