Autism is a developmental disability composed of five different, complex brain disorders. They affect a person’s behavior as well as social and communication skills, states the Autism Science Foundation. Autism can cause significant social, communication and behavioral challenges, adds The Centers for Disease Control and Prevention.
The five autism spectrum disorders are: pervasive developmental delay, Asperger's syndrome, Rett syndrome, childhood disintegrative disorder, and autism, which is sometimes referred to as classic autism, early infantile autism, childhood autism or autistic disorder, according to the Autism Science Foundation. Many people with autism spectrum disorder, or ASD, also have atypical ways of learning, paying attention and reacting to different sensations. Thinking and learning abilities of people with autism can greatly vary from gifted to severely challenged.
A diagnosis can be made by 18 months of age or younger and lasts throughout a person's lifetime. Diagnosing autism is difficult since there is no definitive medical test to diagnose the disorder. Medical professionals look at the child’s behavior and development to make a diagnosis, explains Centers for Disease Control and Prevention.
Autism spectrum disorder occurs among all racial, ethnic and socioeconomic backgrounds, but is almost five times more common among boys than among girls. The CDC estimates that about 1 in 68 children has been identified with autism spectrum disorder.