Understanding Autism : Part 2

by CDC

(Page 2 of 3)

Approximately 2% of children under the age of 18 have a serious developmental disability (DD) and these include mental retardation, cerebral palsy, hearing loss and vision impairment. Of these serious DDs, mental retardation (or intellectual disability) is the most common. A genetic disorder often associated with having mental retardation (MR) or an intellectual disability (ID) that many people recognize is Down syndrome. Current information indicate that having Down syndrome occurs in 1 out of 800 births and is slightly less common than the ASDs. Approximately 17% of children have some type of developmental disability, including more mild conditions such as speech and language disorders, learning disabilities, and ADHD, which appear to be more common than the ASDs.

While developmental disabilities may affect a child's speech or language, physical growth, psychological growth, self-care, or learning, children's health may also be affected by diseases that impact adults as well. A common childhood disease, juvenile diabetes, is prevalent in approximately one in every 400 to 500 children and adolescents, which is in a similar range of the ASDs. However, the ASDs are more common than childhood cancer, which has a prevalence rate of 1.5 per 10,000 children (1 in 300 males and 1 in 333 females have a probability of developing cancer by age 20 according to the National Cancer Institute).

How many children with ASDs are being served through public special education programs?

In 2003 approximately 141,022 children were served under the "Autism" classification for special education services. Not all children with an ASD receive special education services under the classification of "Autism", so the education data underestimate the actual prevalence of the ASDs.

How do the rates of ASDs in special education compare with that of other disabilities?

Autism was added as a special education exceptionality in 1991 and is now the 6th most commonly classified disability in the United States. The most common disability classifications in 2003 were: specific learning disabilities (2,866,908 children served), speech or language impairments (1,129,260 children served), mental retardation (582,663 children served), emotional disturbance (484,479 children served), and other health impairments, which often includes children diagnosed with ADHD (452,442 children served).

Has the number of children being served under an ASD classification in public special education programs changed?

Yes. In 1994 ASDs were the 10th most common disability serving children ages 6-21 in special education. Between 1994 and 2003 the number of children being classified as having an ASD has increased six-fold from 22,664 to 141,022. While it is clear that more children are getting Special Education services for Autism than ever before, it is important to remember that this classification was only added in the early 1990's and the growth of children classified may be in part due to the addition of this as a special education category.

While, it is clear that more children than ever before are being classified as having an Autism Spectrum Disorder, it is unclear how much of this increase is due to changes in how we identify and classify ASDs in people, or whether this is due to a true increase in prevalence. However, using our current standards, the ASDs are the second most common serious developmental disability after mental retardation/intellectual impairment, but are still less common than other conditions that affect children's development, such as speech and language impairments, learning disabilities, and ADHD. The impact of having a developmental disability is immense for the families affected and for the community services that provide intervention and support for these families. It is important that we treat common DDs, and especially the ASDs, as conditions of urgent public health concern, do all we can to identify children's learning needs, and begin intervention as early as possible to enable all children to reach their full potential.

What conditions are included in ASDs?

Autistic disorder is the most commonly known type of ASD, but there are others, including pervasive developmental disorder-not otherwise specified (PDD-NOS) and Asperger syndrome. These three conditions all have some of the same symptoms, but they differ in terms of when the symptoms start, how fast they appear, how severe they are, and their exact nature. These three conditions, along with Rett syndrome and childhood disintegrative disorder, make up the broad diagnosis category of pervasive developmental disorders.

About the Author

www.cdc.gov
The Centers for Disease Control and Prevention (CDC) is one of the 13 major operating components of the Department of Health and Human Services (HHS), which is the principal agency in the United States government for protecting the health and safety of all Americans and for providing essential human services, especially for those people who are least able to help themselves.