CHICAGO - Doctors may want to give stroke victims antidepressants right away instead of waiting until they develop depression, a common complication, a small new study suggests.

The findings could lead to an expanded use for antidepressants. Someday, high-risk people such as stroke patients might take the drugs before suffering depression - just as people now take cholesterol drugs to prevent heart attacks, the lead author said.

The researchers gave low doses of the antidepressant Lexapro to stroke patients. The patients on the drug were 4.5 times less likely to develop depression than patients taking a dummy pill.

More than 700,000 Americans suffer strokes each year, and more than one-third will develop depression in the next two years. Stroke patients with depression recover more slowly and are more likely to die, according to previous research.

"We showed you could in fact prevent the development of depression after stroke," said Robert Robinson of the University of Iowa, who led the study. "I hope I don't have a stroke, but if I do, I would certainly want to be placed on an antidepressant."

Experts say strokes may damage parts of the brain affecting mood. Add to that the stress of relearning simple tasks and adjusting to impairments, and you have a recipe for depression.

The research - funded by the National Institute of Mental Health and appearing in today's Journal of the American Medical Association - was based on an analysis of 176 stroke patients, ranging in age from 50 to 90.

None suffered depression at the start, when they were randomly assigned to three groups: One-third took Lexapro, another third took matching dummy pills, and another received talk therapy focused on problem-solving skills.

After one year, about 9 percent of the Lexapro group had developed depression. That compared with 22 percent of the placebo-takers and 12 percent of those who got problem-solving therapy.

Charles Reynolds, a geriatric psychiatrist at the University of Pittsburgh Medical Center, said he hoped doctors start prescribing preventive antidepressants after stroke.

But with prevention, some patients take pills who never would have needed them, putting them at risk for unnecessary side effects.