Although medication treatment is effective for many individuals with ADHD, there remains an understandable need to explore and develop other interventions that can complement or even substitute for medication.  This is true for a variety of reasons including:

1) Not all individuals with ADHD benefit from medication

2) Among those who do benefit, many have residual difficulties that need to be addressed via other means

3) Some individuals experience adverse effects that prevent them from remaining on medication

4) Many parents have concerns about their child remaining on ADHD medications for a sustained period of time

Over the years, a wide variety of non-medical interventions have been explored.  To date, behavior therapy would generally be considered to be the non-medical intervention with the strongest research support.

Because of the widespread interest in new ADHD interventions - particularly non-pharmaceutical approaches- researchers are trying to discover if there are other ways to help those with ADHD.   A study conducted several years ago in Czechoslovakia tested the effectiveness of  Pycnogenol - an extract from French maritime pine bark - for treating children with ADHD [Trebaticka et. al.(2006). Treatment of ADHD with French maritime pine bark  extract, Pycnogenol. European Journal of Child and Adolescent Psychiatry, 15, 329-325.]

Method -

Participants were 61 6-14-year-old children (50 boys and 11 girls) diagnosed with ADHD using the diagnostic criteria employed in Europe; these are similar but not identical to the criteria used in the USA.  These children were randomly assigned to receive either Pycnogenol (44 participants) or a placebo (17 participants).  Neither parents or teachers were aware of which condition the child had been assigned to; as a result, the ratings that they provided of children's behavior would not be biased by this knowledge.

At breakfast, children in the Pycnogenol condition receive 1 mg/kg of body weight of the extract; children in the placebo condition received a pill with the identical shape and appearance.  This lasted for one month during which no child was supplemented with any other drugs or medications.

Measures

Parent and teacher ratings of children's behavior were obtained just prior to initiating treatment, immediately following 1 month  of treatment, and a final time after treatment had been discontinued for 1 month.  At each time point, parents and teachers completed the appropriate version (i.e., parent or teacher) of the Conners Rating Scale, a widely used behavior rating scale in the assessment of ADHD and which includes sub-scales that specifically measure inattentive and hyperactive-impulsive symptoms. Teachers also completed another measure of inattention/hyperactivity called the Child Attention Problems scale.  Finally, all children were given a modified version of the Wechsler Intelligence Scale for Children, an assessment of intellectual functioning. This was administered by examiners who were also blind to children's  condition.

Results

Teacher ratings - Ratings on the Child Attention Problems Scale indicated a significant decline in attention problems for the Pycnogenol group - but not for children who received placebo - after 1 month of treatment.  Unfortunately, means and standard deviations are not provided so it is difficult to estimate the actual magnitude of the effect.  One month after treatment ended, attention problem scores for children in the Pycnogenol group had returned to their initial level. Similar results were obtained for the items assessing hyperactivity on this scale, i.e., a significant decline after 1 month for the Pycnogenol group only and a return to baseline level a month  after discontinuing treatment. 

Results based on teachers' ratings from the Conners scale were consistent with those reported above; interpretation was complicated, however, by the fact that Pycnogenol and placebo groups were found to differ on this measure at baseline.

Parent ratings - In contrast to the significant treatment effects found for teachers, parent ratings indicated no treatment vs. control group differences. 

Wechsler IQ Scale - After 1 month, children treated with Pycnogenol showed a significant increase in their IQ result relative to children in the control condition. This difference was maintained at the final assessment conducted 30 days after testing ended.  Once again, because means and standard deviations are not provided, it is not possible to estimate the actual magnitude of the obtained effect.

No serious side effects were reported by any of the children receiving Pycnogenol or by their parents.

Summary and Implications

Results of this randomized, placebo-controlled trial of Pycnogenol as a treatment for children and early adolescents with ADHD yielded encouraging results. As summarized above, Pycnogenol treatment was associated with significant declines in teacher, but not parent, ratings of inattentive and hyperactive symptoms. It was also associated with statistically significant increases in estimates of children's intellectual functioning using an abbreviated version of the Wechsler Intelligence Scale. 

It is interesting and important that reductions in ADHD symptoms were only evident in teachers' ratings.  This may reflect the fact that children received Pycnogenol once per day at breakfast, and the beneficial effects that this appeared to provide for many children may have worn off by the later afternoon/early evening when they were back with their parents. If so, this would be equivalent to providing a child with medication only once per day.  Even if this were a long-acting medication, one would not expect the benefits to still be evident throughout the evening when parents would be in a position to observe their child.  The authors provide no discussion of what the expected duration of any benefits provided by Pycnogenol would be, however, so this remains a speculative hypothesis. It would be interesting to test whether providing children with a second dose after school resulted in parents observing benefits as well.

While this appears to be a carefully conducted study, there are several limitations that are important to recognize.  As noted above, because the authors only report the statistical significance of the results they obtained, but not the actual mean values for each group at the different time points, it is not possible to precisely estimate the magnitude of the treatment effects that were obtained. Thus, while we know that Pycnogenol treatment was associated with a significant decline in teachers' ratings of ADHD symptoms, how the size of this decline compares to what is typically obtained in medication studies cannot really be estimated. This is an important point as understanding the likely magnitude of benefits is critically important when evaluating the clinical significance of a treatment.  We also do not know what proportion of children who received Pycnogenol appeared to benefit, which is another important piece of information.

While not a limitation of the study per se, no real information is provided about the mechanism by which Pycnogenol is presumed to have an effect on ADHD symptoms. While it is true that a treatment can be shown to be clearly effective without our necessarily knowing how it works, developing a plausible mechanism by which Pycnogenol treatment would be expected to reduce ADHD symptoms would be an important next step.

Clearly, another important next step would be to replicate these findings in a new sample of children as replicating results for new treatments helps tremendously in making definitive judgements about their effectiveness. Ideally, these would be children diagnosed with the DSM-IV criteria for ADHD - this is what is used in the states - so that the applicability of this treatment to ADHD as diagnosed in North America can be definitively determined. As suggested above, investigating whether a second dose administered after school would eventuate symptom reductions would also be interesting to look at.  Determining the magnitude of any benefits obtained, as well as the proportion of children who derive significant benefit, would also represent important additions to the current work.

Finally, it should be recognized that the fact that Pycnogenol is a "natural" extract does not mean that it may not have potentially adverse effects.  Thus, although there significant side effects were not apparent in this study, one should not assume that the safety of Pycnogenol has been established from this study alone. It is important to document the safety of such "natural" products as would be the case for any pharmaceutical product.