NEW YORK (July 17, 2007) -- Use of the attention deficit/hyperactivity disorder (ADHD) drug Ritalin by young children may cause long-term changes in the developing brain, suggests a new study of very young rats by a research team at Weill Cornell Medical College in New York City.
The study is among the first to probe the effects of Ritalin (methylphenidate) on the neurochemistry of the developing brain. Between 2 to18 percent of American children are thought to be affected by ADHD, and Ritalin, a stimulant similar to amphetamine and cocaine, remains one of the most prescribed drugs for the behavioral disorder.
"The changes we saw in the brains of treated rats occurred in areas strongly linked to higher executive functioning, addiction and appetite, social relationships and stress. These alterations gradually disappeared over time once the rats no longer received the drug," notes the study's senior author Dr. Teresa Milner, professor of neuroscience at Weill Cornell Medical College.
The findings, specially highlighted in the Journal of Neuroscience, suggest that doctors must be very careful in their diagnosis of ADHD before prescribing Ritalin. That's because the brain changes noted in the study might be helpful in battling the disorder but harmful if given to youngsters with healthy brain chemistry, Dr. Milner says.
In the study, week-old male rat pups were given injections of Ritalin twice a day during their more physically active nighttime phase. The rats continued receiving the injections up until they were 35 days old.
"Relative to human lifespan, this would correspond to very early stages of brain development," explains Jason Gray, a graduate student in the Program of Neuroscience and lead author of the study. "That's earlier than the age at which most children now receive Ritalin, although there are clinical studies underway that are testing the drug in 2- and 3-year olds."
The relative doses us
Contact: Andrew Klein
New York- Presbyterian Hospital/Weill Cornell Medical Center/Weill Cornell Medical College