Here are some details on a National Institute of Mental Health study, launched in 2001, which is designed to help determine if Ritalin is effective, and safe, for very young children. Although very little is known about the short- or long-term effects of stimulant medications on this age group, prescription rates for them are rising dramatically.

Zito examined data from two state Medicaid programs and a health maintenance organization, and found that as many as 1.5 percent of children between the ages of 2 and 4 were being prescribed stimulants, anti-depressants, or anti-psychotic drugs. The findings suggested that prescription rates had increased as much as 50 percent between 1990 and 1995. Although the study did not identify which conditions the children were being treated for, in the Washington Post, Zito said she believed that the rise in prescription rates for very young children was definitely related to the recent national increase in Ritalin prescriptions for school-aged children.

Zito's report drew strong media coverage and also attracted the attention of Hillary Clinton, who embarked on a campaign to learn more about the effects of drugs like Ritalin on preschoolers. Subsequently, the National Institute of Mental Health gave $6 million to a consortium of six institutions, led by Dr. Laurence Greenhill of Columbia University, to conduct a five-stage, 40-week study on Ritalin use in preschoolers. This is the first extensive study to be done on this issue.

The Preschool ADHD Treatment Study (PATS) will examine dosing issues, side effects questions, and the efficacy of Ritalin in preschool aged children. As of April 2001, the recruitment of children into the study is underway at the six sites across the country. The effort is to find out how well children ages 3-6 do on a trial of methylphenidate in the short term and over the relative long term (1 year). In order to compare how Ritalin affects younger children to older children, the study will also recruit subjects between 6 and 8 years old.

Some critics have expressed concerns about the recruitment process, saying that it may be hard to diagnose ADHD in such young children. Dr. Howard Abikoff, who is heading up the study at one of the sites at the NYU Child Study Center, says those concerns, while valid, have been addressed by the design of the study. Subjects are required to show persistent symptoms of ADHD for 9 months, rather than the 6 months required by the DSM-IV criteria. Subjects must be attending a school-type setting, and data must be gathered from a teacher or professional in that setting, rather than parents alone. And finally, before a subject is approved for the study, the parents undergo a 10-week training in behavioral therapy specifically designed for parents young kids with ADHD. The child is then reevaluated, and if he or she no longer meets the criteria, will not be considered for the study. "We are not interested in putting children on medication for whom there is not an obvious need," Abikoff said.

The study is designed in the hopes that the resulting data will be extensive enough to meet the FDA requirements for making a ruling as to whether Ritalin is appropriate and safe for use in young children. The researchers are planning to follow up with the subjects of the study over the long term, in order to see how the children treated with Ritalin early in life fare as they grow older.