There
are no medical tests for diagnosing autism. An accurate diagnosis
must be based on observation of the individual's communication,
behavior, and developmental levels. However, because many
of the behaviors associated with autism are shared by other
disorders, various medical tests may be ordered to rule out
or identify other possible causes of the symptoms being exhibited.
A brief observation in a single setting cannot
present a true picture of an individual's abilities and
behaviors. Parental (and other caregivers') input and developmental
history are very important components of making an accurate
diagnosis. At first glance, some persons with autism may
appear to have mental retardation, a behavior disorder,
problems with hearing, or even odd and eccentric behavior.
To complicate matters further, these conditions can co-occur
with autism. However, it is important to distinguish autism
from other conditions, since an accurate diagnosis and early
identification can provide the basis for building an appropriate
and effective educational and treatment program.
Early Diagnosis
Research indicates that early diagnosis is
associated with dramatically better outcomes for individuals
with autism. The earlier a child is diagnosed, the earlier
the child can begin benefiting from one of the many specialized
intervention approaches (see "Treatments and Education").
Diagnostic Tools
The characteristic behaviors of autism spectrum
disorders may or may not be apparent in infancy (18 to 24
months), but usually become obvious during early childhood
(24 months to 6 years).
As part of a well-baby/well-child visit, your
child's doctor should do a "developmental screening"
asking specific questions about your baby's progress. The
National Institute of Child Health and Human Development
(NICHD) lists these five behaviors that signal further evaluation
is warranted:
Does not babble
or coo by 12 months
Does not gesture
(point, wave, grasp) by 12 months
Does not say single
words by 16 months
Does not say two-word
phrases on his or her own by 24 months
Has any loss of
any language or social skill at any age.
Having any of these
five "red flags" does not mean your child
has autism, but because the characteristics of the disorder
vary so much, a child should have further evaluations
by a multidisciplinary team that may include a neurologist,
psychologist, developmental pediatrician, speech/language
therapist, learning consultant, or other professionals
knowledgeable about autism.
While there is no one
behavioral or communications test that can detect autism,
several screening instruments have been developed that
are now used in diagnosing autism.
CARS rating system
(Childhood Autism Rating Scale), developed by Eric Schopler
in the early 1970s, is based on observed behavior. Using
a 15-point scale, professionals evaluate a child's relationship
to people, body use, adaptation to change, listening response,
and verbal communication.
The Checklist for Autism
in Toddlers (CHAT) is used to screen for autism at 18
months of age. It was developed by Simon Baron-Cohen in
the early 1990s to see if autism could be detected in
children as young as 18 months. The screening tool uses
a short questionnaire with two sections, one prepared
by the parents, the other by the child's family doctor
or pediatrician.
The Autism Screening Questionnaire is a 40 item screening
scale that has been used with children four and older
to help evaluate communication skills and social functioning.
The Screening Test
for Autism in Two-Year Olds, being developed by Wendy
Stone at Vanderbilt, uses direct observations to study
behavioral features in children under two. She has identified
three skills areas - play, motor imitation, and joint
attention - that seem to indicate autism.
