Non-stimulant curbs ADHD in fragile X syndrome

NEW YORK (Reuters Health) - L-acetylcarnitine (LAC), a natural substance devoid of side effects, may be considered an alternative to stimulants to control attention deficit hyperactivity disorder (ADHD) in children with the genetic disorder known as fragile X syndrome, researchers conclude based on study they conducted.

Fragile X syndrome is an inherited form of mental retardation. The condition, which may also cause autism and ADHD, results from a genetic defect on the X chromosome.

ADHD is common in young boys with fragile X syndrome and alternatives to methylphenidate and other stimulant medications are needed, note Dr. Giovanni Neri from Universita Cattolica in Rome and colleagues in a Rapid Publication of their study posted online by the American Journal of Medical Genetics.

In a previous study, the team showed that LAC treatment significantly reduced hyperactive behavior in fragile X syndrome boys.

With the current study, the investigators sought to determine the effectiveness of LAC in a larger sample of boys with fragile X syndrome and an established diagnosis of ADHD.

The 63 boys who participated in the study were between 6 and 13 years old. Seven dropped out while 56 completed one year of treatment, and 51 were included in the final analysis. Of these, 24 received LAC and 27 received placebo.

"We observed a stronger reduction of hyperactivity and improvement of social behavior in patients treated with LAC, compared with the placebo group," Neri told Reuters Health.

"LAC is a natural substance, playing an important role in the energy metabolism of the cells, and it is devoid of adverse side effects," the researcher emphasized. "Therefore, in our view, it represents a safe alternative to the use of stimulant drugs for the treatment of ADHD in fragile X syndrome children."

These findings might, in the future, be extended to ADHD in non-fragile X children, who represent a much larger group of individuals, Neri added.

SOURCE: American Journal of Medical Genetics 2008.