Overview of autism spectrum disorder

Autism spectrum disorder (also called ASD or autism) is a neurological disorder and developmental disability characterized by abnormalities in communication and social interaction. Severely restricted interests and highly repetitive behavior are also associated with the disorder.

Symptoms and traits of ASD can include:

lack of language;
difficulty holding a two-way conversation;
echolalia (repetition of words heard);
a desire for order or structure;
obsessive interests (e.g., playing only with toy trains);
atypical eating;
disinterest in other people (e.g., their interests, desires, feelings or lives);
poor eye contact;
sensory issues (i.e., difficulty processing everyday sensations such as sound and touch);
tantrums; and
violent or self-injurious behavior.

People with ASD tend to be visual learners, and some have a photographic memory. Many are able to learn and retain names and facts easily. Some individuals on the spectrum have been known to have remarkable capabilities or savant skills in areas such as mathematics, art and mechanics. Although different estimates exist, it is generally accepted that between 40 and 55 percent of children with ASD also have intellectual disabilities. (Read a related research article in PDF format.) High-functioning individuals with ASD, such as those with Asperger’s syndrome, have average or greater intelligence and communication abilities but usually experience significant difficulties in social interaction along with restricted and repetitive patterns of behavior and interests.

The cause of ASD is not known, although it is widely believed that genetic and environmental factors are involved. Most individuals are diagnosed with the disorder as children, usually by age three. Many of these children will develop seemingly normally for a period of time then regress, typically between 18 and 24 months of age, losing skills they once had. In other children, development of language and social skills is delayed from infancy. Although most people with ASD are diagnosed as children, it is not uncommon for an adult to be diagnosed with the disorder after years of wondering why he or she struggled socially or felt different from peers. In other instances, signs of the disorder can be present in a child or adult, but for various reasons, a diagnosis of ASD is never pursued or officially received.

According to the Centers for Disease Control and Prevention, ASD affects on average 1 in 88 children. Boys are on average four to five times more likely to have the disorder than girls. Parents with one child with ASD have a 5-10 percent chance of having another child with ASD.

There is no known cure for ASD. However, with effective early intervention (i.e., treatment), individuals with ASD can improve significantly, some so much they may show little or no sign of having the condition as adults. However, for most affected individuals, ASD results in significant symptoms and challenges that will exist throughout their lifetime.

To learn more

For more detailed information on autism spectrum disorder, click on the resources below:

For Kids

KidsHealth includes a variety of kid-friendly information on health topics, including autism, and kids with special needs.
The Centers for Disease Control and Prevention Kids’ Quest helps kids to learn more about health and disabilities, including autism.

Online courses about ASD

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Updated: April 18, 2013