Autism:
The Debate Rages
During the last decade, the meteoric rise in the number of autism cases has
become a lightning rod for controversy. Are we seeing an epidemic or just changes
in the way autism is diagnosed? Is there a connection between childhood vaccines
and the rise in autism, or are vaccines just getting a bad rap?
Which side you take probably depends on which experts you talk to—and
when you talk to them. The controversy took an unexpected turn last month when
a group of scientists renounced their own research—a well-publicized 1998
study pointing to a potential link between autism and the MMR (measles, mumps,
and rubella) vaccine. Ten of the 13 researchers, led by Simon Murch of Britain's
Centre for Pediatric Gastroenterology, now say they didn't have enough data
to establish a link.
The debate is by no means over, however. With the number of autism cases increasing
by 172 percent in the last decade, some researchers and advocacy groups still
believe there is a connection. One theory is that autistic children are genetically
susceptible to the mercury in some vaccines. Another theory is that vaccines
are only the final trigger for a buildup of mercury that begins in the mother's
womb. Still another implicates the measles virus in certain vaccines. The Institutes
of Medicine recently held hearings with experts on both sides of the issue and
will publish a report of their findings this month. "The debate will continue
as long as the cause of autism remains a mystery," says Ayda Halker, of
the Autism Society of America. "More research into the origins of autism
needs to be done."
To get clarity on these issues, Paul Sathrum, of NEA's Health Information Network,
spoke with Dr. Andrew Zimmerman, research scientist and pediatric neurologist
at the Kennedy Krieger Institute, Johns Hopkins School of Medicine.
What is autism?
Autism is a neuro-developmental disability
that affects a person's ability to communicate and interact socially—sometimes
profoundly. In fact, there is a spectrum of disabilities related to autism—usually
referred to as pervasive developmental disorders—that can range from mild
to severe. The symptoms of autism typically appear within the first three years
of life and are four times more common in boys than girls.
How is autism diagnosed?
Autism is diagnosed by the observation
of three signs: delayed speech and language, difficulty with social contact,
and repetitive or odd behaviors. All three must be present in a child for a
diagnosis of autism. About one-third of children with autism develop normally
and then begin to regress, usually around 18–24 months of age. Approximately
80 percent of children with autism have a degree of mental retardation, while
20 percent are able to function in the normal range of cognition. This means
that a person who sits next to you glued to a computer screen and who almost
never interacts with others may have a mild form of autism.
Why have we seen such a dramatic increase in autism cases in recent
years?
The three most likely reasons for this sudden, apparent increase are:
improvement in diagnostic techniques, recognition of signs and symptoms, and
a broadening of the definition of autism.
What are the most likely causes of autism?
Autism was first
identified in 1943 by Dr. Leo Kanner. During the 50s and 60s, it was thought
to be caused by bad parenting. In 1970, Stella Chess, professor of child psychiatry
at New York University's School of Medicine, was the first to assign a biological
origin to autism when she observed that one-third of children with rubella,
or German measles, were autistic. Most researchers believe that autism has a
genetic basis, with changes in the brain occurring prior to a baby's birth.
Where did the theory that vaccines could cause autism originate?
The
vaccine and thimerosal (a mercury-based preservative) theory was fueled by observations
that many of the changes seen in autistic children occur around the time childhood
vaccinations are administered. For many people, it's logical to draw a causal
relationship. It is possible that a small handful of childhood vaccinations,
or other environmental factors, may actually exacerbate the process, but there
is no evidence they cause autism. In fact, the overwhelming majority of epidemiological
studies refute the vaccination theory or find no connection. [Editor's Note:
Most of the researchers who believe there is a connection are involved in clinically
based studies.]
What are some approaches schools should take to address the educational
needs of an autistic child?
While autism affects individual children differently, it's important
to remember that all children improve throughout life. The key is early diagnosis
followed by intensive speech/language and behavioral therapies. School personnel
must be given the skills and encouragement to work with children with autism.
A good teacher makes all the difference!
For More
No matter what the cause, the bottom line is that educators need creative and
effective ways of relating to and teaching the growing number of children with
autism in their classrooms. Three excellent resources are:
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