Autism and Autism Spectrum Disorders Fact Sheet
» Autism and Autism Spectrum Disorders Fact Sheet (PDF: 42KB/2 pages)Background
Autism (or autistic disorder)
is a developmental disability. It is one of a group of disorders
known as autism spectrum disorders (ASD) that fall into the broad diagnostic
category of pervasive developmental disorders. Autism, Asperger's
Syndrome and Pervasive Developmental Disorder - not otherwise specified,
are included on the Autism Spectrum. While there is a broad range
of clinical manifestations, ASDs have three common features to varying
degrees: Disordered social skills, disordered communication skills
and repetitive or obsessive behavior. People with autism are severely
affected in each domain. Those with Asperger's Syndrome are particularly
affected in the area of social skills.
Autism Spectrum Disorders occur
in all racial, ethnic and socioeconomic groups. There are four
times more boys than girls diagnosed with an ASD.
In the 1980s, autism was thought
to be a relatively rare disorder affecting one in 10,000 children. Criteria
for diagnosing autism spectrum disorders have changed several times
since autism was first described in 1943. In 1987 and again 1994
major changes were made to the diagnostic criteria expanding the definition
of the disorder. In 1990, autism was added as a special education
disability category. In 2000, the Centers for Disease Control and Prevention
organized the Autism and Developmental Disabilities Monitoring Network,
a multisite, records-based surveillance program, to study the prevalence
of ASDs. The average rate over 14 sites was 1 in 150 or 6.6 per
1000 8-year-olds. A 2004 survey of a sample of Minnesota families
with children found that among children ages 3 - 17 years, the number
of children who had been diagnosed with autism was 1/154.
Signs of autism may appear
anytime before the age of three years. There are no obvious physical
characteristics or laboratory tests for diagnosing autism. A comprehensive
multidisciplinary evaluation including the use of standardized autism
scales is required to diagnose autism and to differentiate it from other
developmental disabilities. An attempt to identify any underlying
health condition that would account for the condition should be undertaken.
Children who have been evaluated exclusively by special education professionals
should not be considered to have undergone a complete diagnostic assessment.1
Scientists think that both
genes and the environment play a role, and there might be many causes
that lead to ASDs. The possible causes of ASDs are under scientific
study but still unknown. ASDs tend to occur more often than expected
among people with Fragile X syndrome, tuberous sclerosis, congenital
rubella and untreated PKU.
Even in the absence of a specific
genetic diagnosis, the recurrence rate in siblings of children with
autism is between 2 percent and 8 percent, meaning the risk of having
a second child with autism is nearly 50-fold over that in the general
population. Twin studies also indicate that genetics play a strong
role in autism.2
While there is not yet a cure
for ASDs, early, intensive treatment can help children with these disorders
reach their full potential. Among the evidence-based methods available
for treatment and education of people with autism, the use of certain
techniques, such as applied behavior analysis (ABA), incidental learning,
and structured teaching have become accepted as effective treatments
ix Research has demonstrated the efficacy of applied behavioral
methods in reducing inappropriate behavior and in increasing communication,
learning, and appropriate social behavior. Other accepted treatment
modalities that address the three affected domains (communication, social
skills and behavior) are not as thoroughly researched as these.
There are at least a dozen
doubtful or discredited treatments for autism. A number of them,
such as chelation therapy or restricted diets, for example, can be harmful,
expensive or both. 3 4 5
Why autism is an issue
More children than ever before
are being classified as having autism spectrum disorders. However,
it is unclear how much of this increase is due to changes in how children
are identified and classified with Autism Spectrum Disorders and how
much is due to a true increase in prevalence. None the less, ASDs
are the second most common serious developmental disability after mental
retardation/intellectual impairment6. The impact of
having a child with an ASD is great for families and for the community
services that provide intervention and support services.
There has been concern from
some that immunizations may play a role in ASD. However, to date
there have been multiple, reliable, scientifically valid studies that
have not found an association between vaccines and autism7.
Illness from vaccine preventable
diseases has decreased significantly since the beginning of the 20th
century. While the US currently has record, or near record, low
cases of vaccine-preventable diseases, the viruses and bacteria that
cause them still exist and can be passed on to people who are not protected
by vaccines. Maintaining high vaccination coverage is essential to preventing
the reintroduction of infectious diseases that once routinely killed
or harmed many infants, children, and adults.8 False
assertions of a vaccine connection to autism threaten that coverage.
While there is no cure for
Autism Spectrum Disorders, there are treatments and therapies, such
as ABA that appear to be effective or that seem promising. Parents
are anxious to have complete and unbiased information upon which to
make treatment decisions. Gathering and disseminating accurate
information on the safety and efficacy of both standard and evolving
treatment approaches remains a challenge for the medical and public
health communities.
For more information
For more information contact
Sarah Thorson
Minnesota Children with Special
Health Needs
Minnesota Department of Health
sarah.thorson@state.mn.us
(1) Barbaresi, WJ: Ktusic, S; Voigt, RG: Autism: A Review of the State of the Science for Pediatric Primary Care Clinicians, Arc Pediatr Adolesc Med. 2006;160:1167-1175.
(2) Muhle R, Trentacoste SV, Rapin I. The genetics of autism. Pediatrics. 2004;113: e472-e486.
(3) Johnson, CP; Myers, SM and the Council on Children With Disabilities, Identification and Evaluation of Children With Autism Spectrum Disorders, Pediatrics, Nov 2007; 120: 1183 - 1215
(4) Millward C, Ferriter M, Calver S, Connell-Jones G. Gluten- and casein-free diets for autistic spectrum disorder. Cochrane Database of Systematic Reviews 2008, Issue 2. Art. No.: CD003498. DOI: 10.1002/14651858.CD003498.pub3.
(5) Williams KW, Wray JJ, Wheeler DM. Intravenous secretin for autism spectrum disorder. Cochrane Database of Systematic Reviews 2005, Issue 3. Art. No.: CD003495. DOI: 10.1002/14651858.CD003495.pub2.
(6) Autism Information Center: Frequently Asked Questions. The Centers for Disease Control and Prevention. http://www.cdc.gov/ncbddd/autism/faq_prevalence.htm last updated 1/30/08
(7) Journal Article Archives: Vaccine-Related Journal Article Abstracts. Immunization Action Coalition http://www.immunize.org/journalarticles/conc_aut.asp
(8) Vaccine Information: The Centers for Disease Control and Prevention. http://www.cdc.gov/vaccines/12/18/08
(9) National Research Council (2001) Educating Children with Autism. Committee on Educational Interventions for Children with Autism. National Academy Press. http://www.nap.edu/catalog.php?record_id=10017#toc
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