Autism is a complex developmental disability that typically appears within the first 3 years of life. Although there is no known cause, autism is considered a neurological disorder that continues throughout a person’s life. Autism spectrum disorder is one of the disorders classified under the “umbrella” of Pervasive Developmental Disorders. Autism is called a “spectrum” disorder because it affects a wide range of behaviors and abilities, the social and communication differences in each individual are extremely varied, and there is no single autism. The most common “types” of pervasive developmental delays are: Autism, Pervasive Developmental Delay-Not Otherwise Specified (NOS), Asperger’s Syndrome, and High Functioning Autism (HFA).
The syndrome typically expresses itself as a range of excess and/or deficit behaviors, skills and competencies. These behaviors are not “abnormal” in and of themselves, but it is the degree to which children labeled as having autism engage in them. Again, typical developing individuals exhibit the same behaviors that children with autism exhibit (self-stimulatory behaviors, tantrums, aggression, non-compliance, etc.), but they can be in excess and interfere with their ability to learn appropriately. Many of these symptoms are expressed as social and communicative deficits, and stereotypic or perseverative excesses. Other symptoms may include a lack of play (cognitive and social), adaptive and self-help skills, fine and gross motor delays, observational learning skills, attention, and imitation skills.
Based on the recent prevalence studies, approximately 1 in 150 births fall somewhere on the autism spectrum, with boys four more times as likely to be affected than girls. However, the overall incidence of autism is consistent throughout the world, and affects people of all race and ethnicity, as well as varying levels of family income, lifestyle, and educational levels.