UC Irvine pediatricians, led by Child Development Center director Jim Swanson (pictured), have found that after three years children who take the popular attention deficit hyperactivity disorder drug, Ritalin, are about an inch shorter and smaller by 4.4 pounds than children who don’t take the drug. In a second study, the researchers found that children with ADHD differed in their response to medications. The UCI research was part of four studies published in the current issue of the Journal of the American Academy of Child and Adolescent Psychiatry, which evaluated the outcomes of children who participated in a nationwide study of ADHD. Swanson is also primary investigator of a $14.6 million grant from the National Institutes of Health to establish a vanguard site for the National Children’s Study in Orange County.