WHAT IS AUTISM?
FROM
WEB MD
NOVEMBER 4, 2010
Understanding
Autism - the Basics
What
Is Autism?
Autism
isn't a disease, it's a symptom. It ranges in severity from a handicap that
limits an otherwise normal life to a devastating disability that may require
institutional care.
Autism
is one of the most common developmental disabilities. Including the milder form
of autism known as pervasive developmental disorder or PDD, autism affects six
to eight out of every 1,000 children.
Children
with autism have trouble communicating. They have trouble understanding what
other people think and feel. This makes it very hard for them to express
themselves either with words or through gestures, facial expressions, and
touch.
A
child with autism who is very sensitive may be greatly troubled -- sometimes
even pained -- by sounds, touches, smells, or sights that seem normal to
others.
Children
who are autistic may have repeated body movements such as rocking or hand
flapping. They may have unusual responses to people, attachments to objects, resistance
to change in their routines, and/or aggressive or self-injurious behavior. At
times they may seem not to notice people, objects, or activities in their
surroundings. Some children with autism also develop seizures, in some cases
not until adolescence.
Many
people with autism are mentally challenged, although most people with PDD have
normal or even above-average intelligence. In contrast to mental retardation
alone, which is characterized by relatively even skill development, people with
autism show uneven skill development. They may have problems in certain areas,
especially the ability to communicate and relate to others. But they may have
unusually developed skills in other areas, such as drawing, creating music,
solving math problems, or memorizing facts. For this reason, they may test
higher -- perhaps even in the average or above-average range -- on nonverbal
intelligence tests.
Autism
typically appears during the first three years of life. Some children show
signs from birth. Others seem to develop normally at first, only to slip
suddenly into symptoms when they are 18 to 36 months old. Autism is four times
more common in boys than in girls. It knows no racial, ethnic, or social
boundaries. Family income, lifestyle, or educational levels do not affect a
child's chance of being autistic.
Some
of the different types of autism spectrum disorders include:
* Autistic disorder. This is what most
people think of when they hear the word "autism." It refers to
problems with social interactions, communication, and imaginative play in
children younger than 3 years.
* Asperger's syndrome. These children don't
have a problem with language -- in fact, they tend to score in the average or
above-average range on intelligence tests. But they have the same social
problems and limited scope of interests as children with autistic disorder.
* Pervasive developmental disorder or PDD
-- also known as atypical autism. This is a kind of catchall category for
children who have some autistic problems but who don't fit into other
categories.
* Rett syndrome. Known to occur mainly in
girls, children with Rett syndrome begin to develop normally. Then they begin
to lose their communication and social skills.
Beginning at the age of 1 to 4 years, repetitive hand movements replace
purposeful use of the hands.
* Childhood disintegrative disorder. These
children develop normally for at least two years, and then lose some or most of
their communication and social skills.
What Causes Autism?
Because autism runs in
families, most researchers think that certain combinations of genes may
predispose a person to autism. It's currently thought that there may be
several different causes of autism
and that there may be several different subtypes of autism.
When a pregnant woman is
exposed to certain drugs
or chemicals during pregnancy,
her child is more likely to be autistic. These risk factors include the
use of alcohol and the use of anti-seizure drugs during pregnancy. In some
cases, autism has been linked to untreated phenylketonuria (called PKU, an
inborn metabolic disorder caused by the absence of an enzyme), rubella (German measles),
and celiac
disease (an inability to tolerate gluten in grains).
Exactly why autism happens
isn't clear. Research suggests that it may arise from abnormalities in
parts of the brain that interpret sensory input and process
language. Imbalances in brain chemicals also appear to play a role.
Researchers have no evidence
that a child's psychological environment -- such as how caregivers treat the
child -- causes autism.
