"Guanfacine appears to be a safe and effective treatment for children with tic disorders and ADHD," said first author Lawrence Scahill, associate professor in the Yale Child Study Center at Yale School of Medicine.
Scahill said this is the first controlled study of guanfacine in children with ADHD. The researchers looked at 34 boys and girls diagnosed with ADHD and a tic disorder. They reported that guanfacine was associated with an average improvement of 37 percent in total score on the ADHD Rating Scale, compared to 8 percent improvement for the placebo. Guanfacine also improved tics and performance on tests of attention and impulse control.
ADHD causes learning and behavioral problems in mostly male children and some adults. The disorder has been treated effectively with Ritalin, methylphenidate and d-amphetamine, but these drugs can have side effects. Over 20 years ago, Donald J. Cohen, M.D., director of the Yale Child Study Center, found that another drug called clonidine could lessen tics and improve ADHD symptoms, but clonidine wears off quickly and can have serious side effects.
Guanfacine was identified as a superior drug to clonidine in the Yale laboratory of Amy F. T. Arnsten, associate professor of neurobiology. Arnsten's team found guanfacine has fewer side effects in animals and strengthens functioning in the brain's prefrontal cortex, which is known to malfunction in ADHD patients.
"This research represents an excellent example of how clinical and basic researchers, collaborating together, can discover new treatments for neuro-psychiatric disorders," said Arnsten.
In addition to Scahill, Cohen and Arnsten, the study authors at Yale include Phillip B. Chappell, M.D., Young S. Kim, M.D., Robert T. Schulz, Lily Katsovich, Elizabeth Shepherd and James F. Leckman, M.D.
The study was supported in part by grants from the Children's Clinical Research Center, Mental Health Research Center and the Tourette Syndrome Association.
Journal
American Journal of Psychiatry