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News
and Notes about Scientific Research on Autism
and other Developmental and Behavioral Disorders
Editor:
Bill Ahearn, Ph.D., BCBA
Director of Research, The New England Center
for Children
Diet
Therapies as Treatment for Autism
Dietary restrictions and
fad diets have been suggested as treatments
for autism and a variety of other disabilities
(e.g., Feingold, 1975; Reiten, 1987). The
theory that food allergies cause or contribute
to autism has no sound scientific evidence
supporting it. Moreover, New York State’s
Department of Health sponsored an independent
panel of parents and professionals to develop
clinical practice guidelines for providing
services to children with autism or pervasive
developmental disorders (NYSDHEIP, 1999).
One of the many of the tasks of this panel
was to review interventions for children
with autism. The panel found no evidence
to support the use of diet therapies as
treatments for autism and does not recommend
their use. There was also no sound scientific
evidence to support the theory that food
allergies cause or contribute to autism.
Additionally, they concluded that intradermal
testing or blood tests for specific antibodies
do not help to develop treatments for autism.
Research conducted at NECC has found that
children with autism seem to be prone to
have eating habits that are highly selective
(Ahearn, Castine, Nault, & Green, 2001).
That is, they tend to be picky eaters and
starches are the foods they are most likely
to prefer. Reiten (1987) suggested that
it is likely these picky eating habits were
produced by the children having difficulty
tolerating the foods they rejected. One
of the substances that some speculate children
with autism are unable to adequately process
is a wheat product, gluten. There is no
reason to believe that a substance, if it
produced an unpleasant reaction or feeling,
would continue to be readily consumed by
the child. More importantly, because children
with autism are prone to selective eating
habits, placing them on diets that will
further restrict the foods that they are
presented with may cause the child with
selective eating habits to become more selective,
they may produce selective eating habits
for children that are not selective, and
they can lead to nutritional deficiencies.
Ahearn,
W.H., Castine, T., Nault, K., & Green,
G. (2001). An assessment of food
acceptance in children with autism or pervasive
developmental disorder - not otherwise specified.
Journal of Autism and Developmental
Disorders, 31, 505-512.
Feingold, B.F. (1975). Why your child
is hyperactive. New York: Random House.
New York State Department of Health Early
Intervention Program. (1999). Clinical
Practice Guideline: Report of the Recommendations.
Autism/Pervasive Developmental Disorders,
Assessment and Intervention for Young Children
(Age 0-3 Years) (Publication No. 4215, pp.
163-194). Albany, NY: Author. (http://www.health.state.ny.us/nysdoh/eip/autism/index.htm#Table_of_Contents)
Reiten,
D.J. (1987). Nutrition and developmental
disabilities: Issues in chronic care. In
E. Schopler & G.B. Mesibov (Eds.), Neurobiological
issues in autism (pp.373-388). New
York:Plenum
Potential
Genetic Links to Autism
It has long been thought
that genetic inheritance plays a significant
role in autism. Several studies were conducted
with fraternal and identical twins that
revealed strong evidence that there is a
genetic component to autism (see Folstein
and Rosen-Sheidley, 2001 for a review of
genetics and autism). The International
Molecular Genetic Study of Autism Consortium
(IMGSAC, 2001) recently completed a study
in which one of two types of genetic testing
was conducted with 152 pairs of siblings
with autism. They reported that a portion
of chromosome 2 was very strongly linked
to the disorder while portions of two other
chromosomes 7 and 16 were also identified
as likely linkages. The goal of studying
the genetics of autism is to come to a better
understanding of what autism is and how
it develops. Identifying particular genes
that contribute to autism may lead to earlier
and more accurate diagnoses.
Early identification of
autism is of obvious importance and improvements
in our understanding of the genetic makeup
of autism will ultimately aid diagnosticians
and clinicians. However, the identification
of genes involved in autism is not likely
to immediately translate into biologically
based interventions. An NIH news release
(NICHD, August 21, 2001) announcing the
findings of the IMGSAC study notes that
the wide range of symptoms displayed by
the persons with autism may suggest that
the disorder is a result of a “complex
interaction between several different genes
involved in brain signaling and development
(and) (un)identified environmental factors
are also likely to play a role.” Therefore,
there is still much research to be done.
Folstein, S.E., & Rosen-Sheidley,
B. (2001). Genetic of autism: Complex aetiology
for a heterogeneous disorder. Nature
Reviews: Genetics, 2(12), 943-955.
International Molecular Genetic Study of
Autism Consortium (2001). A genomewide screen
for autism: Strong evidence for linkage
to chromosomes 2q, 7q, and 16p. American
Journal of Human Genetics, 69, 570-581.
National
Institute of Child Health and Human Development
(2001, August 21). Researchers find new
insights into the genetic foundations of
autism. Retrieved August 21, 2001, from
http://www.nichd.nih.gov/new/releases/genetics_in_autism.cfm.
Further
evidence of secretin ineffectiveness as
a treatment for autism
In a previous version of
the NECC Research Newsletter (April-May
2001), the use of secretin as an intervention
for autism was reported as an unproven treatment.
Secretin is a hormone that exists naturally
in the body and is involved in gastrointestinal
functioning. It was reported in a medical
journal that a single intravenous injection
of secretin had resulted in substantial
improvements in language and behavioral
difficulties for three children diagnosed
with autism. However, this was not a controlled
study and the means of determining whether
the injection had an effect was questionable.
Strong scientific evidence has been growing
that secretin has no clinically meaningful
impact.
Several recent studies
have confirmed secretin’s failure
to improve skill performance or behavior
problems and have addressed some of the
criticisms of earlier investigations. One
criticism of several controlled studies
has been that the children injected with
secretin have not had gastrointestinal problems.
A study, conducted by scientists from Harvard
University’s Medical School and the
University of California, looked at children
diagnosed with autism who were also reported
to have gastrointestinal difficulties (Lightdale
et al., 2001). They found that secretin
produced no increases in language or other
social skills and no decreases in problem
behavior.
Another criticism has been that some children
require multiple injections of secretin
to show beneficial effects. A study by Roberts
and colleagues (2001) investigated the effects
of repeated injections of secretin relative
to injections of a placebo with 64 children
diagnosed with autism. They found no evidence
that secretin was an effective treatment.
They noted that both groups improved in
receptive and expressive communication but
that these gains “were likely attributable
to familiarity with the testing situation,
maturation, and/or ongoing behavioral interventions.”
The study also found that the secretin injection
was associated with: a rash for one child;
a fever, rapid heartbeat, and vomiting for
another child; an increase in irritability
in 3 children; and, a flushing of the skin
for 21% of the children who were injected
with secretin.
Lightdale, J.R., Hayer, C.,
Duer, A., Lind-White, C., Jenkins, S., Siegel,
B., Elliot, G.R., & Heyman, M.B. (2001).
Effects of intravenous secretin on language
and behavior of children with autism and
gastrointestinal symptoms: A single-blinded,
open-label pilot study. Pediatrics, 108(5).
URL:http://www.pediatrics.org/cgi/content/full/108/5/e90.
Roberts, W., Weaver, L., Brian, J., Bryson,
S., Emelianova, S., Griffiths, A., MacKinnon,
B., Yim, C., Wolpin, J., & Koren, G.
(2001). Repeated doses of porcine secretin
in the treatment of autism: A randomized,
placebo-controlled trial. Pediatrics, 107(5).
URL:http://www.pediatrics.org/cgi/content/full/107/5/e71
Research
at The New England Center
There have been several studies conducted
at NECC that have been recently published
or accepted for publication.
Editor’s
note: Rumination is a potentially life-threatening
condition in which food is regurgitated
from the stomach to the mouth and either
re-swallowed or expelled. The following
study describes a treatment that was implemented
to successfully treat a student’s
rumination. Meals were followed by supplementary
feedings of starchy foods.
Dudley,
L.L., Johnson, C., and Barnes, R.S. (2002).
Decreasing rumination using a starchy food
satiation procedure. Behavioral Interventions,
17, 21-29.
A starchy food satiation
procedure was evaluated in an ABAB withdrawal
design on the post-meal rumination of a
nine-year-old girl with autism. During treatment
unlimited quantities of starchy foods were
provided following each meal. High rates
of rumination occurred during baseline conditions,
followed by an immediate decrease in rumination
during treatment. Rumination decreased to
82 and 97% of baseline during the first
and second treatment conditions, respectively.
In addition, follow-up probes were conducted
at irregular intervals for 4 years following
treatment, during which zero or near-zero
rates of rumination were sustained. This
study extends the literature on the functional
relation between increased starchy food
quantity and rumination in adults to rumination
with a young child, and demonstrates maintenance
of the treatment effect for 4 years.
Web
Resources
For information about
autism, visit the National Library of Medicine’s
autism site www.nlm.nih.gov/medlineplus/autism.html.
For information about
applied behavior analysis in the treatment
for autism visit www.behavior.org.
For science-based information
on biomedical treatments and theories in
autism visit www.autism-biomed.org.
For professionally screened
information on health care (including some
treatments for autism and other developmental
disabilities), visit www.quackwatch.com.
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