Passiflora incarnata in the treatment of attention deficit hyperactivity disorder in children and adolescents: a double blind and randomized trial

S. Akhondzadeh, M.R. Mohammadi, F. Momeni, A. Moshaver. Psychiatric Research Centre, Roozbeh Hospital, Tehran University of Medical Sciences, Tehran, Iran.

Attention-deficit hyperactivity disorder (ADHD) is a common early-onset childhood condition that is estimated to occur in 3-5% of school-aged children. Stimulants are the first-line medication in the pharmacotherapy of attention-deficit hyperactivity disorder. Nevertheless, about 30% of children and adolescents do not respond to the stimulants or do not tolerate them. Therefore, the 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 attention-deficit hyperactivity disorder. However, there is no evidence-based document that confirms its efficacy in the treatment of attention-deficit hyperactivity disorder (Berdonces, 2001). We hypothesized that passion flower would be beneficial for the treatment of attention-deficit hyperactivity disorder and report the results of a controlled trial of tablets of passion flower and methylphenidate in the treatment of attention-deficit hyperactivity disorder.

A total of 34 children with attention deficit hyperactivity disorder as defined by DSM IV were randomised to tablet of Passiflora or methylphenidate dosed on weight-adjusted basis at Passiflora 0.04 mg/kg/day (BID) (group 1) and methylphenidate 1 mg/kg/day (BID) (group 2) for a 8 week double blind and randomised clinical trial. The principal measure of the 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 started. Informed consent was received before the administration of any study procedure or dispensing of study medication in accordance with the ethical standards of the investigative site’s institutional review board and with the Helsinki declaration of 1975, as revised in 2000. A two-way repeated measures analysis of variance (time- treatment interaction) was used. The two groups (passion flower and methylphenidate) served as a between-subjects factor (group) and the five measurements during treatment as the within-subjects factor (time) were considered. In addition, a one-way repeated measures analysis of variance with a two-tailed post-hoc Tukey mean comparison test were performed on the change in Parent and Teacher ADHD Rating Scale scores from baseline. To compare the demographic data and frequency of side effects between the protocols, Fisher’s exact test was performed. Intention to treat (ITT) analysis with the last observation carried forward (LOCF) procedure was performed.

No significant differences were observed between Passiflora and methylphenidate on the Parent and Teacher Rating Scale scores over the trial ((F = 0.007, d.f. = 1, P = 0.93 and F = 0.006, d.f. = 1, P = 0.94 respectively) . Two patients dropped out from the methylphenidate group and one from the passion flower group due to lost to follow up, leaving 31 patients who completed the trial. Although the number of dropouts in the methylphenidate group was higher than the Passiflora group, there was no significant difference between the two protocols in terms of the dropouts. In addition, decreased appetite and anxiety/nervousness were observed more often in the methylphenidate group.

The results suggest that Passiflora may be a novel therapeutic agent for the treatment of attention deficit hyperactivity disorder. In addition, a tolerable side effect profile may be considered as one of the advantages of Passiflora in the treatment of attention deficit hyperactivity disorder . Nevertheless , our study is relatively small and our results would need to be confirmed in a larger study.

Berdonces, JL. (2001). Rev. Enferm. 24, 11-14.