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Although
medication treatment is helpful for an estimated 70 to 90% of children
with ADHD, the development of effective alternative treatments is
important for several reasons. First, even for children who
respond well to medication, there often remain residual difficulties
that need to be addressed. Second, some children experience
intolerable side effects that preclude the ongoing use of meds.
Finally, most studies documenting the beneficial effects of stimulant
medication treatment are relatively short-term, and data showing that
stimulant medication improves the long-term prognosis for children with
ADHD is still scarce.
Dietary supplementation of long-chain fatty acids as an intervention
for ADHD has generated considerable interest in recent years.
Certain highly unsaturated fatty acids (HUFAs) are known to play an
important role in many aspects of physical health, and may also play a
role in a wide range of neuro-developmental and psychiatric conditions.
For example, children with ADHD have been shown in several studies to
have low blood levels of HUFAs. Because HUFAs are important for healthy
brain development and functioning, some researchers have suggested that
increasing HUFA levels via dietary supplements could enhance brain
functioning and reduce ADHD symptoms.
In a prior issue of Attention Research Update - www.helpforadd.com/2002/june.htm
- I reviewed 2 studies examining the impact of fatty acid
supplementation on ADHD symptoms. In the first study, 63 children who
were being treated effectively with stimulant medication were randomly
assigned to receive Docasahexaenoic acid (DHA, a type of long-chain
fatty acid) or a placebo over a 4-month period. Computerized tests of
attention and parents' ratings of children's ADHD symptoms did not
differ for treatment vs. placebo groups at 4 months; the authors
interpreted this as evidence against the benefit of fatty acid
supplementation for children with ADHD.
A problem with this conclusion, however, is that participants remained
on medication during the trial. Because these children were all
positive medication responders, their symptoms would already have been
substantially reduced, thus making it difficult to demonstrate
additional benefits of an additional intervention. In children
with ADHD who were not being treated with meds, however, DHA
supplementation might provide benefits that could not be detected here.
In the second study previously reviewed, 41 8-12 year-old children with
developmental dyslexia were randomly assigned to receive either HUFA
supplementation, containing both omega 3 and omega 6 fatty acids, or an
identical-looking placebo. None had been formally diagnosed with
ADHD, although all had above-average scores for high levels of ADHD
based on parent responses to the Conners Rating Scale. After 12
weeks, children receiving active treatment had significantly lower
ratings for inattention and global ADHD symptoms than children who had
received the placebo. Average scores for treated children now
fell towards the upper end of the "normal" range while average scores
for children in the placebo group remained elevated. The degree to
which the results would generalize to children carrying a formal
diagnosis of ADHD was not clear.
At the time, my overall conclusion on the effects of fatty acid
supplementation on children's ADHD symptoms was the following:
"At this point in our knowledge, it seems premature to conclude either
that fatty acid supplementation has no benefits for children with ADHD,
or that such benefits are clearly established. Hopefully, research will
soon be available that will permit a more definitive evaluation."
A study published in the May 2005 issue of Pediatrics (Richardson, A.J., et
al. The Oxford-Durham Study: A randomized, controlled trial of dietary
supplementation with fatty acids in children with developmental
coordination disorder, Pediatrics, 115, 1360-1366) provides important
new data on this interesting issue. This study was conducted in
England, and involved 117 5-12 year old children - about one-third were
girls - diagnosed with Developmental Coordination Disorder (DCD).
Many of these children had elevated levels of ADHD symptoms, although
they were not formally diagnosed with ADHD as part of the study.
DCD involves specific impairments of motor coordination that interferes
significantly with a child's academic achievement and/or activities of
daily living. DCD is believed to affect approximately 5% of children,
and frequently overlaps with ADHD dyslexia. Manifestations of the
disorder in school-age children frequently include difficulties with
the motor aspects of handwriting, playing ball, assembling puzzles,
etc. In the school setting, children with DCD frequently struggle with
written language and/or problems with organizational skills and
attention. Thus, although this is a different disorder from ADHD,
children with DCD experience many similar problems in school.
Participants were randomly assigned to receive dietary fatty acid
supplementation treatment or a placebo. The initial assignment to
treatment vs. placebo lasted for 3 months. At the end of 3 months,
those in the treatment group continued to receive fatty acid
supplementation for 3 additional months while children who had been
receiving placebo were switched to active treatment as well.
Active treatment was a supplement containing 80% fish oil and 20%
evening primrose oil in gelatin capsules. The daily dose of 6
capsules (2 capsules in the early morning, at lunch, and in the late
afternoon provided both omega-3 fatty acids (Dose
received: 558 mg of eicosapentaenoic acid and 174 mg of docosahexaenoic
acid)
, omega-6 fatty acids (Dose received: 60 mg of y-linoleic acid), plus
vitamin E (Dose received: 9.6 mg). Note:
Although this information reflects the doses used in the study,
the authors specifically comment that the optical dosage and
combination of fatty acids remains unknown and that additional studies
are required to determined this. Placebo
treatment consisted of
olive oil capsules that were carefully matched to the active treatment
in both appearance and flavor. Capsules were administered by teachers
during the week and by parents on the weekend.
MEASURES
Several different measures were collected at baseline, 3 months, and 6
months to determine whether fatty acid supplementation improved
children's functioning. First, teachers completed the Conners
Rating Scale, a widely used behavior rating scale to assist in the
assessment of ADHD and other behavioral/emotional problems in
children. Children's reading and spelling achievement was
assessed using a standardized measure of academic achievement.
This measure of reading achievement focused on the ability to read
single words and did not examine reading comprehension. Finally, motor
functioning was assessed with the Movement Assessment Battery for
Children.
RESULTS
The authors first compared children in the treatment and placebo groups
after 3 months to determine whether fatty acid supplementation was
associated with improvements in motor and academic functioning and with
reductions in ADHD symptoms. Results of these analyses indicated
the following:
- There
was little change in children's motor skills and no indication that
treated children showed greater improvement than children receiving
placebo.
- Before
treatment, average reading and spelling achievement scores were about 1
year below age level for children in both groups. After 3 months,
children receiving fatty acid supplementation gained an average of 9.5
months in reading and 6.6 months in spelling. Children receiving
placebo, in contrast, gained only 3.3 months in reading and 1.2 months
in spelling. Thus, compared to the placebo group, gains made by treated
children were highly significant.
- At
baseline, the average score on the ADHD scale of the Conners was
elevated in both groups. Scores for treated children showed a
significant decline while scores for placebo children were essentially
unchanged. Within the treated group, 16 children initially had scores
on the ADHD scale in the clinically elevated range; after 3 months, 7
no longer fell in this range. Among children in the placebo
group, only 1 of 16 children showed this same improvement.
Recall that after 3 months, children in the placebo group began
receiving fatty acid supplementation and treated children continued
receiving the supplement. Assessments of motor functioning,
academic achievement, and ADHD symptoms were examined again 3 months
later. Here is a summary of what was found:
- As
before, gains in motor functioning were modest.
- Children
who began receiving treatment showed an average gain of 13.5 months in
reading and 6.2 months in spelling. Children who continued on
active treatment continued to make substantial gains as well: 10.9
months in reading and 5.3 months in spelling.
- ADHD
symptoms declined significantly in children who began receiving
supplementation. Scores continued to decline among children
continuing on active treatment.
SUMMARY
AND
IMPLICATIONS
The results of this double-blind,
placebo controlled study are
exciting: among 117 children with developmental coordination disorders,
dietary supplementation of omega-3 and omega-6 fatty acids was
associated with substantial gains in reading and spelling as well as
significant reductions in ADHD symptoms. Although these children
were not diagnosed with ADHD, many had elevated levels of ADHD
symptoms, and may have qualified for an ADHD diagnosis had they been
formally evaluated.
The gains in children's reading and
spelling achievement were
particularly noteworthy: children who received 6 months of treatment
showed an average gain of over 20 months and a spelling gain of about
12 months. Thus, despite not receiving any specific academic
intervention during this time, they went from being about a year below
age level to essentially catching up with their peers.
Although this is a very important
finding, as with all exciting new
findings, replicating this result in a second study would be very
important to do. In addition, because the measure of reading
achievement focused on single-word reading, the extent to which
comparable gains may have occurred in children's reading comprehension
is unknown. This would be an important issue to examine in
subsequent research. The authors also note that additional
studies are needed to establish the optimal composition of fatty acid
treatments - they used a 4:1 ratio of omega 3 to omega 6 fatty acids -
as well as the optimal dosage.
It is important to emphasize that
this was a carefully conducted and
well-controlled study, in which neither participants, teachers,
parents, or those administering the achievement tests were aware of
when children were receiving active supplementation and when they were
receiving placebo. Because of these controls, the benefits
reported can confidently be attributed to the effects of the fatty acid
supplementation. As the authors note, however, the study was not
designed on the possible mechanisms by which these effects were
obtained (e.g., what specific changes in brain functioning were induced
by the supplements that resulted in children's gains).
It is also important to emphasize
that although many children in this
sample of children with DCD showed elevated levels of ADHD symptoms,
and that ADHD symptoms improved with treatment, participants in this
study did not carry an ADHD diagnosis. Thus, the extent to which
children with ADHD would benefit from this treatment approach is
unclear, and, as noted above, a prior study of fatty acid
supplementation in children with ADHD failed to find such
benefits. In this study, however, children were already being
managed effectively on medication, making additional gains hard to
document, and only a single fatty acid was supplemented rather than
both omega-3 and omega-6 fatty acids as was done here.
Given the extremely positive results
of the current investigation, it
would appear that new research on the impact of fatty acid
supplementation on the behavior and academic functioning in children
with ADHD would be extremely important to carry out. To my
knowledge, the gains in academic achievement that were demonstrated
here have not been reported in any prior study of ADHD interventions,
and are truly exciting. Learning whether children with ADHD, many
of whom struggle academically, would also benefit from fatty acid
supplementation should thus be a high research priority.
Thanks again to Cogmed for supporting this issue of Attention Research
Update
(c) 2006 David Rabiner, Ph.D.
Information presented in Attention Research Update is for informational
purposes only, and is not a substitute for professional medical
advice. Although newsletter sponsors offer products and services
that I believe will be of interest to subscribers, sponsorship of
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