University of Illinois at Chicago researchers are comparing two drugs commonly used to treat attention deficit hyperactivity disorder to determine if genetic factors predict which children will respond to either or both drugs.
Many different medications are used to treat ADHD, including stimulants and non-stimulants, says Dr. Mark Stein, principal investigator of the National Institute of Mental Health-funded study and director of the Hyperactivity, Attention, and Learning Problems Clinic at UIC.
"Unfortunately, clinicians are unable to predict in advance who will respond or not respond to a particular medication," Stein said.
The study will be conducted in Chicago and New York. Stein and colleagues will enroll 160 children and adolescents between ages 7 and 17 in Chicago. Dr. Jeffrey Newcorn of Mt. Sinai School of Medicine heads the New York site.
Participants will undergo psychiatric evaluations, IQ and achievement tests, a blood test, an electrocardiogram and a physical exam. They will then receive several doses of atomoxetine (a non-stimulant medication), melthylphenidate (a stimulant medication), and a placebo, during a carefully monitored blinded dosing sequence to determine their optimal response to each medication.
During the 12 to 15-week study, researchers will assess the children's ADHD symptoms, social functioning, problem-solving skills and sleep patterns to determine the efficacy and tolerability of each medication.
Previous research conducted by Stein and colleagues found that children with a variant form of a dopamine transporter gene -- a variant known to be associated with ADHD -- responded poorly to stimulant medication and had more side effects at lower doses. The new study will test whether patients with this genetic marker respond better to non-stimulant medication.