Passiflora incarnata in the treatment of attention-deficit hyperactivity disorder in children and adolescents

Author(s): Shahin Akhondzadeh, MR Mohammadi and F Momeni

Background: Attention-deficit hyperactivity disorder (ADHD) is a common early-onset childhood disorder that is estimated to occur in 3 to 5% of school-aged children. Stimulants are the first-line medication in the pharmacotherapy of ADHD. Nevertheless, approximately 30% of children and adolescents either do not respond to or do not tolerate stimulants. Therefore, new treatments, including alternative medicine, are still needed. Passion flower consists of the fragmented or cut, dried aerial parts of Passiflora incarnata L., and is a folk remedy for anxiety and ADHD. However, there is no evidence-based document that confirms its efficacy in the treatment of ADHD. Objectives: We hypothesized that passion flower would be beneficial for the treatment of ADHD and report the results of a controlled trial of tablets of passion flower and methylphenidate in the treatment of this disorder. Patients & methods: A total of 34 children with ADHD as defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM IV) were randomized to receive tablets of passiflora or methylphenidate, dosed on a weight-adjusted basis. Group 1 received passiflora 0.04 mg/kg/day (twice daily) and group 2 received methylphenidate 1 mg/kg/day (twice daily) in an 8-week, doubleblind, randomized clinical trial. The principal measure of outcome was the Parent and Teacher ADHD Rating Scale. Patients were assessed by a child psychiatrist at baseline, 14, 28, 42 and 56 days after the medication was started. Results: No significant differences were observed between passiflora and methylphenidate on the Parent and Teacher Rating Scale scores over the course of the trial (F = 0.007, df = 1, p = 0.93; and F = 0.006, df = 1, p = 0.94, respectively). Both treatment groups demonstrated significant clinical benefit over the period of treatment as assessed by both parents and teachers. Although the number of dropouts in the methylphenidate group was higher than in the Passiflora group, there was no significant difference between the two protocols in terms of dropouts. In addition, decreased appetite and anxiety/nervousness were observed more often in the methylphenidate group. Conclusions: The results suggest that passiflora may be a novel therapeutic agent for the treatment of ADHD. In addition, a tolerable sideeffect profile may be considered as one of the advantages of passiflora. Nevertheless, our study is relatively small and our results require confirmation in a larger study.