St. Johns Wort Fails to Improve ADHD

KENMORE, Wash.— St. John’s wort (Hypericum perforatum)failed to improve attention-deficit/hyperactivity disorder (ADHD) symptoms in a recent randomized control trial at Bastyr University (JAMA. 2008;299(22):2633-2641). The trial was conducted between March 2005 and Aug. 2006 among a volunteer sample of 54 children, aged 6 to 17 years, who met criteria for ADHD. After a placebo run-in phase for one week, participants were randomly assigned to receive 300 mg of H. perforatumstandardized to 0.3% hypericin(n=27), or a matched placebo (n=27) three times daily for eight weeks. Other ADHD medications were not allowed during the trial. No significant difference was found in the change in ADHD Rating Scale-IV scores from baseline to week eight between treatment and placebo groups: inattentiveness improved 2.6 points within the h. perforatum  group vs. 3.2 points with the placebo group (P=0.68); hyperactivity improved 1.8 points vs. 2.0 points in the placebo group (P=0.89). There was also no difference between the two groups in the percentage of participants who met criteria for improvement on the Clinical Global Impression Improvement Scale or the number of participants who experienced adverse effects during the study period.
Michael McGuffin, president of the American Herbal Products Association (AHPA) commented on the study’s findings: “The degradation of the product to less than half the amount of the marker compound means the quality of this product was seriously impaired by the end of the study. Overall, this is a study of an uncommon use of St. John’s wort that used a poor quality product.”  He also pointed out that the marketing of St. John’s wort for ADHD is not common and the supporting reference for the authors’ assertion was a survey conducted in 2000 to 2001 that found five out of 117 children with ADHD had taken St. John’s wort at some time in their life. These five children had not necessarily taken St. John’s wort for ADHD, and were not necessarily taking it at the time of the survey.