The results provide additional evidence that antidepressants may play a key role in helping improve the mental health of suicidal youth, said Cynthia Fontanella, co-author of the study and assistant professor of social work at Ohio State University.

The findings are especially important now, because antidepressant use dropped in 2003 after the Food and Drug Administration issued a black box warning that some antidepressants may increase the risk of suicidal behavior for pediatric patients. A black-box warning is the most serious type of warning in prescription drug labeling.

"We found that antidepressant treatment had a protective effect on readmission," Fontanella said. "Although the findings are preliminary, our results should be reassuring to child psychiatrists who may have been concerned about prescribing antidepressants since the FDA warning."

But another key finding from the study showed that hospitalized youth who were prescribed three or more medications from different drug classes for mental health issues had a 3-fold increased risk of being readmitted within a month of discharge.

Fontanella conducted the study with Ohio State researchers Jeffrey Bridge, assistant professor of pediatrics, and John Campo, chief of child and adolescent psychiatry. Both are also associated with the Research Institute at Nationwide Children's Hospital in Columbus.

The study appears in the December issue of The Annals of Pharmacotherapy.

The researchers did a retrospective study of 318 Medicaid-covered adolescents who were admitted to three major psychiatric hospitals in Maryland because of attempted suicide or suicidal behaviors.

They examined hospital medical records for the adolescents and recorded all medication changes - including additions, discontinuations and changed dosages that occurred during the hospital stay.