The study is likely to increase the controversy over whether depressed teenagers should routinely be prescribed newer antidepressants like Paxil and Zoloft.

In October 2004, the Food and Drug Administration ordered drug companies to add strong warnings to the labels of antidepressants after clinical trials suggested that some drugs increased the risk of suicidal thinking and behavior in children and teenagers. The drugs seem to make a small number of patients extremely agitated, a reaction that can lead to violent or suicidal thoughts, psychiatrists say.

Since the warning, prescriptions for antidepressants have been flat for adults, according to NDCHealth, which tracks pharmaceutical information, and they have fallen slightly for adolescents.

Now some psychiatrists say they believe that the pendulum has swung unfairly against the drugs and that depressed people are not receiving treatment that could help them.

But other doctors continue to say that the drugs should be prescribed cautiously, especially because clinical trials have found that the drugs work only modestly better than placebo pills for most patients.

Antidepressants are among the most widely prescribed drugs in the United States, with almost 200 million prescriptions written each year.