Side Effects of Ritalin Greater in Preschool

Times Staff Writer

The first systematic study of using Ritalin to treat preschool children with attention deficit hyperactivity disorder has found that the drug reduced their symptoms but caused greater side effects than usually seen in older children, researchers said Monday.

The findings mean “very small children may benefit but they should be closely monitored,” said Dr. Thomas R. Insel, director of the National Institute of Mental Health, which paid for the $18-million study.

Among the side effects, researchers said the drug appeared to slow children’s growth rates. They grew about a half-inch less in height and weighed 3 pounds less than expected, based on estimates of their growth.

Stephen Hinshaw, chair of the psychology department at UC Berkeley who was not involved in the study, said the findings showed that the drug should be given only to children ages 3 to 5 with more severe symptoms -- and only if they can be regularly seen by their doctors.


Ritalin, also called methylphenidate, is approved as a treatment for ADHD only in children age 6 and older.

The research was initiated in response to the outcry that ensued after the Journal of the American Medical Assn. reported in 2000 that as many as 200,000 preschoolers were on Ritalin, an unapproved, or “off-label,” use of the drug.

At the time, then First Lady Hillary Rodham Clinton expressed concern about widespread use of the drug and called for more research.

The research, published in the November issue of the Journal of the Academy of Child and Adolescent Psychiatry, was conducted at six academic centers in the U.S. over the course of 70 weeks. It looked at 183 children with moderate to severe ADHD.

“You have children who are very aggressive and doing things that are unsafe, like running into the middle of the road or jumping off high pieces of playground equipment,” said Dr. James McGough of UCLA, one of the study authors. “These are kids who, if they did not get treatment, would get kicked out of preschool.”

Before being assigned to receive Ritalin, children and their parents received 10 weeks of behavioral therapy.

The children were then assigned to receive up to 22.5 milligrams daily of Ritalin. Daily doses for older children range from 15 to 50 milligrams daily.

Side effects, including insomnia, weight loss and decreased appetite, caused 21 children, or 11%, to drop out of the study. One child had a seizure that was thought to be related to the medication.


Children who completed the study had improved symptoms according to assessments by their parents and preschool teachers. But about a third of parents reported moderate to severe side effects throughout the study, including emotional outbursts and irritability.

Researchers will follow the children for five years to see if their growth catches up as they get older.