Context: Stimulant medication can effectively treat 60% to 70% of youth with attention-deficit/hyperactivity disorder (ADHD). Yet many parents seek alternative therapies, and Hypericum perforatum (St John's wort) is 1 of the top 3 botanicals used.
Objective: To determine the efficacy and safety of H. perforatum for the treatment of ADHD in children.
Design, setting, and participants: Randomized, double-blind, placebo-controlled trial conducted between March 2005 and August 2006 at Bastyr University, Kenmore, Washington, among a volunteer sample of 54 children aged 6 to 17 years who met Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) criteria for ADHD by structured interview.
Intervention: After a placebo run-in phase of 1 week, participants were randomly assigned to receive 300 mg of H. perforatum standardized to 0.3% hypericin (n = 27) or a matched placebo (n = 27) 3 times daily for 8 weeks. Other medications for ADHD were not allowed during the trial.
Main outcome measures: Performance on the ADHD Rating Scale-IV (range, 0-54) and Clinical Global Impression Improvement Scale (range, 0-7), and adverse events.
Results: One patient in the placebo group withdrew because of an adverse event. No significant difference was found in the change in ADHD Rating Scale-IV scores from baseline to week 8 between the treatment and placebo groups: inattentiveness improved 2.6 points (95% confidence interval [CI], -4.6 to -0.6 points) with H. perforatum vs 3.2 points (95% CI, -5.7 to -0.8 points) with placebo (P = .68) and hyperactivity improved 1.8 points (95% CI, -3.7 to 0.1 points) with H. perforatum vs 2.0 points (95% CI, -4.1 to 0.1 points) with placebo (P = .89). There was also no significant difference between the 2 groups in the percentage of participants who met criteria for improvement (score < or = 2) on the Clinical Global Impression Improvement Scale (H. perforatum, 44.4%; 95% CI, 25.5%-64.7% vs placebo, 51.9%; 95% CI, 31.9%-71.3%; P = .59). No difference between groups was found in the number of participants who experienced adverse effects during the study period (H. perforatum, 40.7%; 95% CI, 22.4%-61.2% vs placebo, 44.4%; 95% CI, 25.5%-64.7%; P = .78).
Conclusion: In this study, use of H. perforatum for treatment of ADHD over the course of 8 weeks did not improve symptoms.
Trial registration: clinicaltrials.gov Identifier: NCT00100295.