On June 11th, JAMA published a study concluding that St. John’s Wort doesn’t work for Attention Deficit Hyperactivity Disorder (ADHD). The study compared St. John’s Wort (300 mg) to a placebo in 54 children (ages 6-17), who took one of the two treatment options for eight weeks. In the end, researchers said the herb didn’t work any better than placebo.

Following publication of the study, the American Herbal Products Association (AHPA), Silver Spring, MD, came forward to point out several crucial flaws. First and foremost, said AHPA president Michael McGuffin, the marketing of St. John’s Wort for ADHD is very uncommon. In fact, the supporting reference for the authors’ assertion was a survey conducted in 2000-2001, which found five out of 117 children with ADHD had taken St. John’s Wort at some time in their life. According to AHPA, 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. In other words, this is hardly a supportive reference for the researchers’ assertion.

Furthermore, AHPA points out, the authors admitted that the product had seriously degraded by the end of the trial. The H. perforatum used in the study was reported to be standardized to 0.3% hypericin; however, at the end of the study the product contained only 0.13% hypericin and 0.14% hyperforin. “I don’t believe that this test material would pass muster if the proposal was submitted to NIH’s National Center for Complementary and Alternative Medicine (NCCAM) today because something as basic as ensuring the quality through the duration of the trial was not assured,” said Steven Dentali, PhD, AHPA’s CSO and past chairperson of NCCAM’s Product Quality Working Group.
 
“It is possible that a product standardized to at least 3% hyperforin could benefit children with ADHD symptoms if it were delivered in a method that limits oxidation,” Weber et al. note in the study.

“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,” said Mr. McGuffin. “Overall, this is a study of an uncommon use of St. John’s Wort that used a poor quality product.”