St. John's wort not effective for treating ADHD

Children and teens with attention-deficit/hyperactivity disorder (ADHD) who were treated with the herb St. John's wort did not have any greater improvement in ADHD symptoms compared to those who received placebo, according to a study in the June 11 issue of JAMA, the Journal of the American Medical Association.

ADHD affects 3 to 12 percent of children in the United States. Up to 30 percent of these children do not respond to pharmaceutical medications or have adverse effects such as nausea, insomnia, or weight loss from the medications, according to background information in the article. "For these reasons, many parents seek complementary or alternative medicine for their children with ADHD. Complementary or alternative medicine treatments used for pediatric ADHD include massage, dietary changes, dietary supplements, and herbal treatments. In the United States, the most common herbal treatments used by children with ADHD are St John's wort, Echinacea species, and Ginkgo biloba," the authors write.

Wendy Weber, N.D., Ph.D., M.P.H., of Bastyr University, Kenmore, Wash., and colleagues conducted a clinical trial of St. John's wort (Hypericum perforatum) with 54 children and adolescents with ADHD, age 6 to 17 years, to determine whether this agent was effective in lessening the severity of ADHD symptoms. Twenty-seven participants were randomly assigned to receive 300 mg of H perforatum standardized to 0.3 percent hypericin (a compound derived from H perforatum) and 27 participants received a matched placebo, three times daily for eight weeks. Other medications for ADHD were not allowed during the trial.

The researchers found that there were no significant differences between the two groups in the change in ADHD rating scale scores from the start of the trial to week 8 and in change in scores rating inattentiveness and hyperactivity. There was also no difference in the proportion of participants who were rated as much or very much improved regarding ADHD symptoms on another measurement scale. No statistically significant difference was found between the two groups in the proportion of participants who experienced 1 or more rash, nausea/vomiting, headache, or sunburn during the trial.

"To our knowledge, this is the first placebo-controlled trial of H perforatum in children and adolescents. The results of this study suggest that administration of H perforatum has no additional benefit beyond that of placebo for treating symptoms of child and adolescent ADHD," the authors write.

(JAMA. 2008;299[22]:2633-2641.