DisclaimerThere is no medical test for ASDs. Doctors look at behavioral
symptoms to make a diagnosis. These symptoms may show up within
the first few months of life or may appear at any time before
the age of 3.
In the past decade, research has found several behaviors that
help to establish an early diagnosis of ASD. Also, research has
shown that a diagnosis of autism at age 2 can be reliable,
valid, and stable.[1]
But despite evidence that ASDs can often be identified at 18
months or younger, many children do not receive final diagnoses
until they are much older. This delay results in lost
opportunities for specialized early intervention. The earlier an
ASD is diagnosed, the earlier needed interventions can begin.
CDC’s “Learn the Signs. Act Early.” campaign has interactive
charts to help you
keep track of your child’s development.
General Developmental Screening and Surveillance
The diagnosis of an ASD takes two steps. The first step is
developmental
screening and
surveillance
during well-child doctor visits. Screening tests used solely for
identifying children with developmental disabilities should be
given to all children during the 9-month, 18-month, and 24- or
30-month well-child visits. If your child's health care
professional does not routinely check your child with such a
test, ask that it be done.
ASD-Specific Developmental Screening
Screening for ASDs is one way to improve early
identification of children who need of more in-depth evaluation.
Early intervention may be vital in preventing a cascade of
problems that may affect later functioning. All children should
be screened for ASDs at the 18-, 24-, and 30-month “well-child”
visits. Additional screening may be needed if a child is at high
risk for ASDs (has a sibling or parent with an ASD) or if
symptoms warrant. See the Screening Resources box for links to autism screening tools
and their descriptions from the American Academy of Pediatrics (AAP).
Screening for High-Functioning Autism or Asperger Syndrome
Until recently, screening tools often did not identify children
with mild ASD, such as those with high-functioning autism or
Asperger syndrome. Today, the
Autism Spectrum Screening Questionnaire (ASSQ), the
Australian Scale for Asperger's Syndrome,
and the
Childhood Asperger Syndrome Test (CAST) are some of the tools that are reliable for identifying
school-age children with Asperger syndrome or high-functioning
autism. These tools focus on social and behavioral impairments
in children without significant language delay.
If your child's doctor sees any of the possible signs of an ASD
during a well-child visit, further evaluation is needed.
What screening tools can do
Screening tools can help identify children who might have
developmental delays. Screening tools can be specific to a
disorder (for example, autism) or an area (for example,
cognitive development, language, or gross motor skills), or
they can be general, including multiple areas of concern.
What screening tools cannot do
Screening tools cannot give sure evidence of developmental
delays, and they cannot be used to make a diagnosis. A
positive screening result should be followed by a thorough
assessment. Screening tools cannot provide in-depth
information about an area of development. |
Comprehensive Diagnostic Evaluation
The second step of diagnosis is comprehensive evaluation.
Thorough evaluation may include clinical observations, parent
interviews, developmental histories, psychological testing,
speech and language assessments, and possibly the use of one or
more autism diagnostic scales. Because ASDs are complex
disorders, a comprehensive evaluation may also include physical,
neurological, and genetic testing.
Many tools have been designed to assess ASDs in young children,
but no single tool should be used as the only basis for
diagnosing autism. Diagnostic tools usually rely on two main
sources of information—parents’ or caregivers’ descriptions of
their child’s development and direct observation of behavior.
Examples of autism diagnostic tools include:
- Autism Diagnosis Interview–Revised (ADI–R)[2]
- Autism Diagnostic Observation Schedule-Generic (ADOS–G)[3]
- Childhood Autism Rating Scale (CARS)[4]
- The Gilliam Autism Rating Scale (GARS)[5]
What can I do if I think my child has an ASD?
If you or your doctor thinks there could be a problem, ask
for a referral to see a developmental pediatrician or other
specialist. You can also call your local early intervention
agency (for children under 3) or public school (for children 3
and older). To find out who to speak to in your area, check with
the
National Dissemination Center for Children with Disabilities.
Today, the main research-based treatment for ASDs is
intensive structured teaching of skills, often called behavioral
intervention. It is very important to start this intervention as
early as possible to help your child reach his or her full
potential. Acting early can make a real difference!
Even if your child has not been diagnosed with an ASD, he or
she may be eligible for early intervention services. The
Individuals with Disabilities Education Act (IDEA) says that children under the age of 3 who
are at risk of having substantial developmental delays may be
eligible for services. These services are provided through an
early intervention system in your state. Through this system,
you can ask for an evaluation. To learn more about early
intervention, click here
National Dissemination Center for Children with Disabilities.
For tips
on how to share your concerns with your pediatrician, visit the
First Signs website.
Disclaimer: We have provided a link to
these sites because they have information that may be of interest to you. CDC does not necessarily endorse the views or information presented on
these sites. Furthermore, CDC does not endorse any commercial products or information that may be presented or advertised on these sites.
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Additional Information
Clinical Guideline: Screening and Diagnosis of Autism
(American Academy of Neurology)
Clinical Guideline: The Pediatrician's Role in the Diagnosis and
Management of Autistic Spectrum Disorder in Children (American
Academy of Pediatrics)
[1]
Lord C, Risi S, DiLavore PS, Shulman C, Thurm A, Pickles
A. Autism from 2 to 9 years of age.
Arch Gen Psychiatry. 2006 Jun;63(6):694-701.
[2]Tadevosyan-Leyfer
O, Dowd M, Mankoski R, Winklosky B, Putnam S, McGrath L,
Tager-Flusberg H, Folstein SE. A principal components
analysis of the autism diagnostic interview-revised.
Journal of the American Academy of Child and Adolescent
Psychiatry, 2003; 42(7): 864-872.
[3]Lord C,
Risi S, Lambrecht L, Cook EH, Leventhal BL, DiLavore PC,
Pickles A, Rutter M. The autism diagnostic observation
schedule-generic: a standard measure of social and
communication deficits associated with the spectrum of
autism. Journal of Autism and Developmental Disorders,
2000; 30(3): 205-230.
[4]Van
Bourgondien ME, Marcus LM, Schopler E. Comparison of
DSM-III-R and childhood autism rating scale diagnoses of
autism. Journal of Autism and Developmental Disorders,
1992; 22(4): 493-506.
[5] Gilliam
JE. Gilliam Autism Rating Scale (GARS). Austin, TX:
Pro-Ed; 1995
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