The experiments, to determine the safety and efficacy of Ritalin in preschoolers, have advocates up in arms - they think researchers are playing fast and loose with the brains of children.

"Where's the limit?" asked Dr. Ellen Isaacs, a member of the Coalition Against the Violence Initiative, a grass-roots group in the Washington Heights section of Manhattan. "Are they going to give it to kids in the womb?"

The rationale of the nationwide experiment on the preschoolers seems noble - Ritalin is already prescribed by doctors like lollipops without any sound medical evidence to show that it's safe for a child's developing brain.

About 2 million kids nationwide, nearly a quarter-million of them between ages 2 and 4, take Ritalin and other psychiatric drugs, according to a March 2000 report by the Journal of the American Medical Association.

The report inspired then-First Lady Hillary Clinton, who was a candidate for the U.S. Senate at the time, to prod the White House to look at ways to stop the alarming trend, and that translates into experiments. Some thought Clinton's motives were political, others applauded her.

The National Institute of Mental Health subsequently gave $6 million to a consortium of six institutions, led by Dr. Laurence Greenhill of Columbia University, to conduct the Ritalin study. New York University also is part of the group.

Two-thirds of the more than 300 kids in the nationwide study called Preschool ADHD Treatment Study (PATS) will be under 6 years old.

They are looking for kids with symptoms of Attention Deficit Hyperactivity Disorder who have never been medicated.

Members of the coalition two weeks ago protested outside Columbia Presbyterian Medical Center, which is affiliated with Columbia University, handing out leaflets alerting parents, schools and community groups.

The coalition is worried researchers will offer money for subjects or give parents false hopes that their children will be cured. They also worry that the unknown, long-term side effects of the drugs might harm kids.

Advocates are also wondering how researchers are going to properly diagnose the preschoolers - some of who can't express themselves thoroughly.

"Obviously, if it's the researchers doing the diagnosis, it is in their interest to diagnose kids with ADHD because they need them for the study," said Leonard H. Glantz, a law professor at Boston University and author of a book on the ethics of researching on children.

"Unlike doctors, researchers don't have the best interest of the patient in mind."

Greenhill said the five-stage, 40-week study has been reviewed and re-reviewed by five ethics panels "to make sure the rights of the children and their families' rights are protected."

Researchers will seek kids by advertising, by referrals from local doctors and by sending flyers to private schools - since they are prohibited from recruiting at public schools, Greenhill said.

The children will be diagnosed by a special group of researchers composed of up of six institutions, including Johns Hopkins, University of California at Los Angeles, University of California at Irvine, and Duke, said Greenhill, who insisted the parents will only be given money to get and from the hospital.

Greenhill is seeking more than 60 kids whose parents will first receive training to see if their child's behavior improves. The second stage involves low-dose medication that's later upgraded, Greenhill said.

The fourth stage includes a placebo experiment, where some kids get a sugar pill. Advocates say children will suffer from withdrawal symptoms because Ritalin is addictive.

Parents have to sign consent forms for each stage, including the last, which includes a gradual tapering off or continuation of the drug.

Informed of the study she inspired, Clinton spokeswoman Karen Dunn said, "Hillary Clinton is very concerned about the increased use of Ritalin in young children and has strongly supported efforts to determine whether it is being used appropriately and effectively."

That sounds politically and morally correct, but the folks in Washington, D.C., aren't going to be around to see what becomes of these kids who donate their brains to science.