NATIONAL INSTITUTES OF HEALTH
National Institute of Child Health and Human Development
NIH NEWS RELEASE
FOR IMMEDIATE RELEASE
Tuesday, November 27, 2001
Contact:
Robert Bock
(301) 496-5133
STUDY CONFIRMS SECRETIN *******NO****** MORE EFFECTIVE THAN PLACEBO IN
TREATING AUTISM SYMPTOMS
The latest in a series of studies on secretin has failed to
show that giving the digestive hormone to children with
autism alleviates symptoms of the disorder, according to a
study funded by the National Institute of Child Health and
Human Development.
The study, which appeared in the November 2001 issue of the
"Journal of the American Academy of Child and Adolescent
Psychiatry", found that patients with autism who received a
form of the hormone derived from swine showed no
statistically significant improvements in the core symptoms
of the disorder when compared to when the same patients
received a placebo. (The core symptoms of autism involve
social and communications skills.) In certain secondary
measures of autism, patients receiving secretin also showed
no improvement when compared to when they received a
placebo.
The researchers used porcine secretin, a form of the
hormone derived from pigs, and the form most commonly used
in diagnostic tests of the digestive system. Previous
studies have also tested laboratory manufactured secretin
as a treatment for autism. The current study tested
porcine secretin to rule out the possibility that the
naturally occurring form of the hormone might have a
different effect than does the synthetic version.
"These results, in addition to those from other secretin
clinical trials, do not provide evidence to support using
the hormone to treat the symptoms of autism," said Duane
Alexander, M.D., director of the National Institute of
Child Health and Human Development (NICHD), one of the
sponsors of the study.
Interest in secretin as a possible treatment for autism, a
neurodevelopmental disorder characterized by social and
communication problems and repetitive behaviors and
interests, arose from reports of children with autism whose
symptoms improved after receiving a single dose of the
hormone. Secretin is routinely given during tests to
diagnose intestinal ailments, but its safety and
effectiveness in treating autism were not known. Since
1999, more than a half dozen studies examined whether or
not secretin could reduce symptoms in children with autism,
with little evidence of benefit. Varying the doses of the
hormone and giving it on more than one occasion have not
proved useful in treating the disorder.
"Our study reiterates the need to perform careful studies
of any new treatment -- even one that appears promising --
before routinely prescribing it to patients," said the
study's first author, Thomas Owley, M.D., Assistant
Professor of Child and Adolescent Psychiatry at the
University of Chicago.
The study, conducted at sites in Illinois, California, and
Utah, included 56 children with autism, ranging from age
three to age 12. The children met the autistic disorder
criteria for two scales used to measure the "core" symptoms
of autism, the Autism Diagnostic Interview-Revised (ADI-R)
and the Autism Diagnostic Observation Schedule (ADOS). The
core symptoms of autism pertain to social and communication
skills. The researchers confirmed the diagnosis using the
DSM-IV criteria, currently the standard for diagnosing
autism from the American Psychiatric Association. Children
who did not meet the requirements of all three scales did
not participate in the study.
Children were randomized to receive either an intravenous
dose of secretin, followed by a dose of harmless saline
(salt) solution four weeks later, or an intravenous dose of
saline, followed by a dose of secretin four weeks later.
The children went through detailed evaluations before
receiving treatment, and then every two weeks, to see if
their symptoms of autism showed any change. These
evaluations continued until eight weeks after treatment, to
ensure that the researchers would detect any positive
effect.
Using a change in the ADOS social-communication score as a
primary measure, researchers found no statistically
significant differences in the group when they received
secretin versus when they received the placebo.
Assessments of secondary measures showed no treatment
effect at all between the secretin and placebo groups. The
results were the same eight weeks after the treatment.
None of the five controlled clinical trials published on
secretin, either in the porcine form or in the synthetic
form, given at varying doses, have shown any improvement
over the placebo in symptoms of autism.
Open label studies -- those in which researchers know what
they are giving to the patients -- comparing secretin with
the saline solution, have suggested that some improvements
might result when secretin is used in patients with autism.
The current study was "double-blinded," meaning that
neither the patients nor the researchers who treated and
evaluated the patients knew when the patients received the
secretin or the placebo. The purpose of studying a
treatment (secretin) against a placebo (saline) in a
double-blinded design is to assure objectivity in the
evaluation of a person's response to a medication by
eliminating any bias that might be caused by the
expectations of the participants. Scientifically, a
double-blinded, placebo-controlled design is considered
optimal in investigations designed to determine whether a
treatment is effective. This study also used a cross-over
design, in which the same patients are evaluated on placebo
and treatment, rather than comparing one group receiving
treatment and another receiving placebo. Because of its
objective nature, the study provides strong evidence that
the use of secretin does not improve autistic symptoms and
behaviors. However, it is not possible to say from such a
relatively small study whether or not there may be a small
sub-group of autistic patients who may experience some
benefit from secretin.
"This multi-site study analyzed possible changes in
autistic symptoms based on very well accepted measures,"
said Laurence Stanford, Ph.D., a program officer in NICHD's
Mental Retardation and Developmental Disabilities Branch.
"The study results reinforce the findings of other
controlled clinical trials on secretin that, for most
people with autism, the hormone is not an effective
treatment."
The study was conducted as part of the Collaborative
Network on the Neurobiology and Genetics of Autism,
supported by the NICHD and the National Institute on
Deafness and Other Communication Disorders (NIDCD), both
parts of the National Institutes of Health (NIH), the
biomedical research arm of the federal government.
Additional support for the trial came from the National
Institute of Mental Health and the National Center for
Research Resources at the NIH, and from the University of
California-Davis Medical Investigation of
Neurodevelopmental Disorders (MIND) Institute.
The NICHD is one of the Institutes comprising the NIH, the
premier biomedical research agency in the federal
government. The NICHD supports and conducts research on
development before and after birth; maternal, child, and
family health; reproductive biology and population issues;
and medical rehabilitation. NICHD publications, as well as
information about the Institute, are available from the
NICHD Web site,
http://www.nichd.nih.gov, or from the NICHD
Clearinghouse, 1-800-370-2943, e-mail
NICHDClearinghouse@mail.nih.gov>>
