Keeley Schwindt was a high school freshman who became moody and angry, and one day swallowed a massive dose of aspirin to see what would happen.

Kevin Rider was a cerebral 12-year-old who gradually lost interest in his schoolwork and pleasure in his precious Boy Scout activities.

Like millions of boys and girls beginning adolescence, they were diagnosed with depression, and their parents decided to put them on medication.

Soon Schwindt, of Garden City, Kan., was thriving, playing on the basketball team, later heading off to college. Last year, at age 19, she won a teen beauty pageant, and her parents believe antidepressants helped saved the girl's life.

Rider, of Orem, Utah, wasn't so fortunate. He had good and bad stretches on the medication. One day, at age 14, he was found dead with a gunshot wound to the head, an apparent suicide that his mother, Dawn Rider, blames on the drugs. "He was not at all a suicidal person, not at all," she said. "The drugs ended his life."

In public hearings today a panel of experts convened by the Food and Drug Administration is set to address the underlying question: Could the same drugs that doctors say have helped make life more enjoyable and fulfilling for millions also increase the risk of suicide in some children?

The hearings come weeks after health officials in England effectively banned doctors from prescribing a range of antidepressants to children, citing concerns over suicide risk. As the debate heats up in this country, some psychiatrists say that the uncertainties could vastly alter the treatment of depression in American minors.

"The potential implications of this are enormous, because FDA decisions carry so much weight in terms of what medications are available to patients and families," said Dr. James McCracken, director of child and adolescent psychiatry at UCLA's Neuropsychiatric Institute. McCracken said concerns over suicide "are genuinely confusing to many doctors who've used these drugs for some time and are comfortable with them. To suggest that the drugs may be harmful for kids is an about-face that is very hard to understand."

The debate is over how to interpret research on SSRIs (selective serotonin reuptake inhibitors), the popular class of antidepressants that includes Prozac, Paxil and Zoloft. All agree that a risk of suicide shadows any treatment for depression. It's not just that the disease itself puts a person at increased risk, psychiatrists say; it's also that effective therapy can lift mood and energy level just enough to prompt someone to action.

Nonetheless, U.S. government researchers who reviewed adult studies of SSRIs decided in the early 1990s that the medications had mostly minor side effects and did not increase suicide risk. Subsequent trials of drugs such as Prozac, Paxil and Zoloft in children and adolescents suggested to most psychiatrists that the drugs were safe and effective in younger patients too.

But no law compels drug manufacturers to publish all the relevant information on a drug, and often negative findings are withheld. In recent years, a raft of previously unpublished information has emerged from SSRI trials in children — convincing some scientists that the drugs are not as safe and effective as initially portrayed.

"What you're seeing is one of the greatest divides in medicine, between what published articles and their authors say, and what the data actually show," said Dr. David Healy, director of the North Wales Department of Psychological Medicine in Britain. Healy is one of several researchers who contend that authors of industry-sponsored SSRI trials in children have made the drugs look better than they really are. In one trial, he said, researchers masked serious side effects by noting vaguely that some children became "emotionally labile [changeable]," when actually the youngsters reported thoughts of taking their own lives, what's known as suicidal thinking.

In its warning on SSRI use in children last December, the British Medicines and Healthcare Products Regulatory Agency, Britain's version of the FDA, cited evidence of a twofold to threefold increase in suicidal thinking with some of the drugs — from about 1.5% to 3% or more, in some trials. (The agency exempted Prozac from this warning, but the drug is not licensed for use for children or adolescents in England.)

Yet Dr. Graham Emslie, a psychiatrist at the University of Texas Southwestern Medical Center in Dallas, who has conducted dozens of SSRI trials in children, said this evidence amounted to little more than scattered case reports. Emslie heads a task force of specialists reviewing data from some 2,000 children in antidepressant trials. Late in January, the group reported that "taking SSRIs or other new generation antidepressant drugs does not increase the risk of suicidal thinking or suicide attempts."

"It's very hard to interpret single case reports without investigating them more thoroughly," Emslie said. "I've been doing these kinds of studies for more than 10 years now, and I've never seen any of these problems" of suicidal thinking.

Many members of the task force have received drug company funding for research. They deny that those arrangements bias their judgment. They also point out that thoughts of suicide are not the same thing as the act itself, and that no child committed suicide during the trials. The dark thoughts need to be taken very seriously, they said; but the teenage years are often colored with morbid fantasies, even in those who are not clinically depressed.

Dr. Jane Garland, a psychiatrist and director of the Mood and Anxiety Disorders Clinic at BC Children's Hospital in Vancouver, Canada, has noticed that a small number of children in her practice have an "odd" reaction to SSRI medications. "Generally speaking, if you're really suicidal, the antidepressants will make you less so," she said. "But then there's this subgroup of young patients who aren't suicidal who take the drugs and report this odd and sudden onset of obsessive suicidal thinking. They say, 'I think I'm losing my mind,' and 'I don't want to feel this way.' "

Rider, the Utah mother, who is scheduled to testify in Washington today, said this described what happened with her son. "He was telling me the drugs made him feel strange, he said he didn't like what they did to him, and all along I took the advice of our doctor" to continue the medication, she said. "Here I thought I was such a good mother, and I listened to a doctor over my own son. I'll feel guilty about that for the rest of my life."

Already, many parents of troubled youngsters who might benefit from treatment with SSRIs are weighing the possibility, however remote, of an increased risk of suicidal thinking.

Deborah Gongora, 30, a mental health patient advocate in Victorville, has two children prone to depression, 14-year-old David and his sister, 12-year-old Devin. David has struggled with bouts of depression since grade school, but recently has found some relief in group and individual counseling sessions, without antidepressants.

Devin has tried talk therapy too, but doesn't like it or find it helpful. "With her, right now, I believe antidepressants are the right thing to do," said Gongora. "I was depressed myself at her age. I was suicidal, so I know what it looks like. For me, the most important thing is having an open and honest relationship with her, so I have some idea what she's thinking. If a child is depressed and contemplating suicide already, you have to do anything to stop them."

Some signs of suicidal thinking are obvious, child psychiatrists say: talking about death; total withdrawal from friends; giving away prized possessions. A sudden increase in drug or alcohol use also can be a warning. Mock attempts, and actions such as Kansas teenager Schwindt's experiment with aspirin, are ominous. So is erratic, wildly uncharacteristic behavior. Not long before his death, Kevin Rider was caught climbing on a neighbor's roof in the middle of the night — a bizarre stunt, like nothing the boy had ever done before, said his mother.

Those doctors who believe that suicidal thinking is a risk with some SSRIs say that reaction is most likely to occur within the first two weeks of starting on the antidepressant or if the patient quits the drug suddenly. For now, the only thing all sides agree on is that researchers need to focus directly on the possible link between SSRIs and suicidal thinking, rather than leaving the subject open to debate.