Note
- Additional information on the herbal compound tested in the study described
below can be found at
www.adhd-clarity.com/index.html
This link is provided because many subscribers may be interested in learning
more about the herbal compound. I have no relationship whatsoever with the
clinic/company that distributes this compound and am not recommending that
anyone try it.
Many parents, health care professionals, and educators agree that there is
a pressing need to develop effective treatments for ADHD to complement or
substitute for traditional medication and behavior therapy approaches.
This is because such treatments do not work for everyone, important difficulties
often remain even when these treatments are effective, and evidence for the
long-term benefits of these treatments remains less compelling than one would
like. In addition, in the case of medication treatment, some individuals experience
intolerable side effects and many have concerns about taking ADHD medication
for an extended period.
One alternative approach to treating ADHD has relied on the use of Compound
Herbal Preparations (CHP) derived from traditional Chinese medicine.
Practitioners of this approach believe that such preparations have important
cognitive enhancing properties because they supply essential nutrients, fatty
acids, phospholipids, amino acids, B vitamins, minerals, and other micronutrients
that are important for optimal brain growth and development. As a treatment
for ADHD, the idea is that many individuals with ADHD have deficiencies in
essential nutrients that compromise healthy brain development and result
in ADHD symptoms. Providing these nutrients via an appropriately prepared
herbal compound thus has the potential to be therapeutic and reduce these
symptoms.
This idea was tested recently in a randomized-controlled trial of a specific
CHP for children with ADHD [Katz, Kol-Degani, & Kav-Venaki (2010). A
compound herbal preparation (CHP) in the treatment of ADHD: A randomized
controlled trial.
Journal of Attention
Disorders. Published online on March 12, 2010.] Participants
were 120 6-12 year-old children newly diagnosed with ADHD based on a comprehensive
diagnostic evaluation. These children were all evaluated at the Sheba
Medical Center, one of the largest university-affiliated tertiary care centers
in Israel.
Children were randomly assigned to receive either the CHP (n=80) or a placebo
(n=40) that was specially prepared to taste, smell, and look similar to the
herbal formula. Randomization was done in a 2:1 ratio because the treatment
was to last 4 months, and investigators wished to minimize the number of
children who would receive placebo treatment for which no benefit was anticipated.
Active ingredients in the CHP - brand name Nurture & Clarity - included
Paeoniae Alba, Withania Somnifera, Centella Asiatica, Spirulina Platensis,
Bacopa Monieri, and Mellissa Officinalis. All raw herbs used in the
preparing the compound were approved by the Israeli Ministry of Health as
safe, food-grade herbs.
Neither parents, children, research assistants who tested the children or
staff members who distributed the appropriate formula to participants knew
who received the CHP and who was given the placebo. To confirm that
the placebo preparation could not be distinguished from the CHP, 20 Israeli
medical students were provided with both preparations and asked which was
which; these students were unable to reliably tell them apart. Based on the
information provided, therefore, this appears to have been a carefully conducted
trial with strong randomization and blinding procedures.
Prior to beginning treatment with the CHP or placebo, children were administered
the Test of Variables of Attention (TOVA), a widely used computerized test
of attention and impulsivity. In the TOVA, children sit in front of
a computer and are instructed to respond using a particular key whenever
a designated stimulus appears. When any other stimulus flashes they
are not supposed to respond. The test lasts for over 20 minutes and good
performance requires the child to sustain attention to an uninteresting task
for a reasonably long period of time.
Failing respond when a response is required - errors of omission - are believed
to reflect problems with sustaining attention. Responding when the
wrong stimulus appears - errors of commission - reflect impulsive responding.
Other measures from the TOVA include response reaction time and reaction
time variability. Children receive a score on each scale that compares
their performance to age-matched peers from a large normative sample.
They are also assigned an overall score, again based on age appropriate norms.
Following baseline administration of the TOVA, children were treated with
the CHP or placebo preparation over a 4-month period. At the end of
4 months the TOVA was administered a second time. This enabled the
researchers to determine whether children receiving the CHP demonstrated
significant improvement on the test compared to those who received placebo.
-
Results -
At the follow-up assessment, data was obtained on 73 of 80 children who received
the CHP compared to only 19 of 40 who received placebo. The significantly
greater drop-out rate among placebo-treated children reflected the greater
number of parents who were not satisfied with their child's response and
who withdrew to pursue other options.
Results from the TOVA were analyzed in 2 primary ways. First, within
each group, researchers tested whether there was significant improvement
from pre-test to post-test. Then, they directly compared CHP vs. placebo
differences controlling for age and sex. Because preliminary analyses
indicated that results were consistent across different ADHD subtypes, i.e.,
inattentive, hyperactive-impulsive, and combined, children with each subtype
were combined in all analyses.
For the within group analyses, children in the CHP group showed statistically
significant improvement on all indices of the TOVA. In fact, their
average fell well within the normal range on all TOVA variables. In
contrast, those in the placebo group showed small declines on each TOVA variable
and continued to perform in the below average range.
A direct comparison of the two groups yielded equally strong results, as
CHP- treated children made significantly greater improvement than placebo-treated
children on every TOVA scale. The magnitude of these group differences
would be considered large.
The authors conducted a final analysis in which they assumed that all control
children who withdrew would have improved as much as the average child in
the CHP group had they continued and that all CHP children who withdrew would
not have improved at all. Even when these conservative assumptions
were made, children in the CHP group were still performing significantly
better on average.
It should also be noted that careful assessments were conducted during the
4-month trial on the safety and tolerability of the CHP. No serious
adverse effects were reported and the rate of even mild adverse events among
CHP-treated children was actually lower than for children who received placebo.
-
Summary
and Implications -
Results from this randomized-controlled trial of a compound herbal treatment
for ADHD clearly indicate significant improvement on an objective measure
of sustained attention and impulsive responding, i.e., the TOVA. Given
how carefully the trial was conducted, and the magnitude of the effects that
were found, this is an encouraging and impressive result. Beyond the TOVA
results, the fact that over 90% of parents kept their child on the herbal
compound over 4 months - compared to under 50% of children receiving placebo
- suggests that they were observing real-world benefits in their child and
were not receiving pressure from teachers to 'do something'. Clearly,
these findings underscore the potential benefits of this herbal compound
in the treatment of ADHD.
Despite these impressive results, however, there remain several important
reasons for caution regarding the potential benefits of this treatment.
First, this is only a single study and replication with another sample would
be important for increasing confidence in the findings. The need for
replicating treatment effects is important for any treatment approach and
hopefully such work is already underway.
Second, and I believe this is especially important, the outcome measures
used to evaluate treatment impact were unfortunately limited. While
the TOVA certainly offers objective evidence of improved attention and reduced
impulsive responding, the measurement battery would have ideally included
behavior ratings made by parents and teachers. Such ratings would provide
a clearer indication than the TOVA results of whether treatment yielded reductions
in ADHD symptoms that were observed at home and at school, which are the outcomes
that really matter. Although the fact that most parents kept their
child on the herbal compound for the 4 months suggests that 'real-world'
reductions in ADHD symptoms were evident, collecting the standardized behavior
ratings is necessary to confirm this.
Finally, the study provides no real information on how long any benefits
of this treatment would be sustained. Is this compound something children
need to take indefinitely - as is often true for medication - or do the benefits
persist even after the compound is no longer administered? This would
be important information to collect in subsequent work.
These limitations not withstanding, this is an interesting and important
study that highlights the need for additional research on this promising
intervention approach for children with ADHD.