New federally financed drug research reveals a stark disparity: children covered by Medicaid are given powerful antipsychotic medicines at a rate four times higher than children whose parents have private insurance. And the Medicaid children are more likely to receive the drugs for less severe conditions than their middle-class counterparts, the data shows.

Those findings, by a team from Rutgers and Columbia, are almost certain to add fuel to a long-running debate. Do too many children from poor families receive powerful psychiatric drugs not because they actually need them  but because it is deemed the most efficient and cost-effective way to control problems that may be handled much differently for middle-class children?

The questions go beyond the psychological impact on Medicaid children, serious as that may be. Antipsychotic drugs can also have severe physical side effects, causing drastic weight gain and metabolic changes resulting in lifelong physical problems.

On Tuesday, a pediatric advisory committee to the Food and Drug Administration met to discuss the health risks for all children who take antipsychotics. The panel will consider recommending new label warnings for the drugs, which are now used by hundreds of thousands of people under age 18 in this country, counting both Medicaid patients and those with private insurance.

Meanwhile, a group of Medicaid medical directors from 16 states, under a project they call Too Many, Too Much, Too Young, has been experimenting with ways to reduce prescriptions of antipsychotic drugs among Medicaid children.

They plan to publish a report early next year.

The Rutgers-Columbia study will also be published early next year, in the peer-reviewed journal Health Affairs. But the findings have already been posted on the Web, setting off discussion among experts who treat and study troubled young people.

Some experts say they are stunned by the disparity in prescribing patterns. But others say it reinforces previous indications, and their own experience, that children with diagnoses of mental or emotional problems in low-income families are more likely to be given drugs than receive family counseling or psychotherapy.

Part of the reason is insurance reimbursements, as Medicaid often pays much less for counseling and therapy than private insurers do. Part of it may have to do with the challenges that families in poverty may have in consistently attending counseling or therapy sessions, even when such help is available.

“It’s easier for patients, and it’s easier for docs,” said Dr. Derek H. Suite, a psychiatrist in the Bronx whose pediatric cases include children and adolescents covered by Medicaid and who sometimes prescribes antipsychotics. “But the question is, ‘What are you prescribing it for?’ That’s where it gets a little fuzzy.”

Too often, Dr. Suite said, he sees young Medicaid patients to whom other doctors have given antipsychotics that the patients do not seem to need. Recently, for example, he met with a 15-year-old girl. She had stopped taking the antipsychotic medication that had been prescribed for her after a single examination, paid for by Medicaid, at a clinic where she received a diagnosis of bipolar disorder.

Why did she stop? Dr. Suite asked. “I can control my moods,” the girl said softly.

After evaluating her, Dr. Suite decided she was right. The girl had arguments with her mother and stepfather and some insomnia. But she was a good student and certainly not bipolar, in Dr. Suite’s opinion.

“Normal teenager,” Dr. Suite said, nodding. “No scrips for you.”

Because there can be long waits to see the psychiatrists accepting Medicaid, it is often a pediatrician or family doctor who prescribes an antipsychotic to a Medicaid patient  whether because the parent wants it or the doctor believes there are few other options.

Some experts even say Medicaid may provide better care for children than many covered by private insurance because the drugs  which can cost $400 a month  are provided free to patients, and families do not have to worry about the co-payments and other insurance restrictions.

Image Dr. Derek H. Suite, a psychiatrist in the Bronx, says he sees many children on antipsychotic drugs who do not need them. Credit... Suzanne DeChillo/The New York Times

“Maybe Medicaid kids are getting better treatment,” said Dr. Gabrielle Carlson, a child psychiatrist and professor at the Stony Brook School of Medicine. “If it helps keep them in school, maybe it’s not so bad.”

In any case, as Congress works on health care legislation that could expand the nation’s Medicaid rolls by 15 million people  a 43 percent increase  the scope of the antipsychotics problem, and the expense, could grow in coming years.

Even though the drugs are typically cheaper than long-term therapy, they are the single biggest drug expenditure for Medicaid, costing the program $7.9 billion in 2006, the most recent year for which the data is available.

The Rutgers-Columbia research, based on millions of Medicaid and private insurance claims, is the most extensive analysis of its type yet on children’s antipsychotic drug use. It examined records for children in seven big states  including New York, Texas and California  selected to be representative of the nation’s Medicaid population, for the years 2001 and 2004.

The data indicated that more than 4 percent of patients ages 6 to 17 in Medicaid fee-for-service programs received antipsychotic drugs, compared with less than 1 percent of privately insured children and adolescents. More recent data through 2007 indicates that the disparity has remained, said Stephen Crystal, a Rutgers professor who led the study. Experts generally agree that some characteristics of the Medicaid population may contribute to psychological problems or psychiatric disorders. They include the stresses of poverty, single-parent homes, poorer schools, lack of access to preventive care and the fact that the Medicaid rolls include many adults who are themselves mentally ill.

As a result, studies have found that children in low-income families may have a higher rate of mental health problems  perhaps two to one  compared with children in better-off families. But that still does not explain the four-to-one disparity in prescribing antipsychotics.

Professor Crystal, who is the director of the Center for Pharmacotherapy at Rutgers, says his team’s data also indicates that poorer children are more likely to receive antipsychotics for less serious conditions than would typically prompt a prescription for a middle-class child.

But Professor Crystal said he did not have clear evidence to form an opinion on whether or not children on Medicaid were being overtreated.

“Medicaid kids are subject to a lot of stresses that lead to behavior issues which can be hard to distinguish from more serious psychiatric conditions,” he said. “It’s very hard to pin down.”

And yet Dr. Mark Olfson, a psychiatry professor at Columbia and a co-author of the study, said at least one thing was clear: “A lot of these kids are not getting other mental health services.”

The F.D.A. has approved antipsychotic drugs for children specifically to treat schizophrenia, autism and bipolar disorder. But they are more frequently prescribed to children for other, less extreme conditions, including attention deficit hyperactivity disorder, aggression, persistent defiance or other so-called conduct disorders  especially when the children are covered by Medicaid, the new study shows.

Although doctors may legally prescribe the drugs for these “off label” uses, there have been no long-term studies of their effects when used for such conditions.

The Rutgers-Columbia study found that Medicaid children were more likely than those with private insurance to be given the drugs for off-label uses like A.D.H.D. and conduct disorders. The privately insured children, in turn, were more likely than their Medicaid counterparts to receive the drugs for F.D.A.-approved uses like bipolar disorder.

Even if parents enrolled in Medicaid may be reluctant to put their children on drugs, some come to rely on them as the only thing that helps.

“They say it’s impossible to stop now,” Evelyn Torres, 48, of the Bronx, said of her son’s use of antipsychotics since he received a diagnosis of bipolar disorder at age 3. Seven years later, the boy is now also afflicted with weight and heart problems. But Ms. Torres credits Medicaid for making the boy’s mental and physical conditions manageable. “They’re helping with everything,” she said.