BAKERSFIELD, Calif. -- Depression is so common among heart patients that last month the American Heart Association recommended patients be routinely screened for depressive symptoms.

Results from a new study following 1,000 people with stable heart disease have shown that experts have good reason to be concerned: patients who had symptoms of depression were 50 percent more likely to suffer a heart attack, stroke, or a mini-stroke.

But upon further analysis, doctors discovered the depression itself did not appear to hurt the heart. Depressed patients did not take good care of themselves, and it was their unhealthy lifestyle that raised the odds of heart attack and stroke.

Patients with depression were twice as likely to smoke and to lack physical exercise. They were also less likely to take their medications as prescribed -- drugs like aspirin, blood pressure pills, and statin drugs that help prevent heart attacks and strokes.