In a study of 376 youngsters ages 6 through 17 with major depression, Zoloft worked better than dummy pills at reducing symptoms. Sixty-nine percent of children who took Zoloft for 10 weeks showed a substantial reduction in symptoms, compared with 59 percent who took dummy pills.
While that difference was not huge, the findings are significant because depression treatments have frequently failed to outperform placebos in previous research in children, said Dr. Christopher Varley a University of Washington psychiatry professor.
Children tend to respond to placebos more than adults do because they are more suggestible, said Varley, who wrote an editorial accompanying the study in Wednesday's Journal of the American Medical Association.
The study was funded by Pfizer Inc., which makes Zoloft.
Many doctors already prescribe Zoloft for depressed children based on evidence that it works in adults, and will welcome results affirming that practice, Varley said.
"There's a crying need for all sorts of studies like this one," Varley said.
Study author Dr. Karen Dineen Wagner agreed.
"We have very little information about what's safe and effective for treating this disorder in youth," said Wagner, director of child and adolescent psychiatry at the University of Texas Medical Branch in Galveston.
By some estimates, depression affects as many as 8 percent of teenagers and 3 percent of younger children.
Zolofty's side effects in children included diarrhea and agitation but were mostly mild and uncommon.
Prozac is the only newer anti-depressant officially approved for treating depression in children.
The government recently warned against using a similar drug, Paxil, in youngsters because of a potential increased risk of suicide.
Both drugs and Zoloft are called selective serotonin re-uptake inhibitors, which increase brain activity of the mood-regulating chemical serotonin.
By Lindsey Tanner