Autism is a complex developmental disability that typically appears during the first three years of life. The result of a neurological disorder that affects the functioning of the brain, autism impacts the normal development of the brain in the areas of social interaction and communication skills. Children and adults with autism typically have difficulties in verbal and non-verbal communication, social interactions, and leisure or play activities.

Autism is one of five disorders coming under the umbrella of Pervasive Developmental Disorders (PDD), a category of neurological disorders characterized by "severe and pervasive impairment in several areas of development," including social interaction and communications skills (DSM-IV-TR). The five disorders under PDD are Autistic Disorder, Asperger's Disorder, Childhood Disintegrative Disorder (CDD), Rett's Disorder, and PDD-Not Otherwise Specified (PDD-NOS). Each of these disorders has specific diagnostic criteria as outlined by the American Psychiatric Association (APA) in its Diagnostic & Statistical Manual of Mental Disorders (DSM-IV-TR).

Prevalence of Autism

Autism is the most common of the Pervasive Developmental Disorders, affecting an estimated 1 in 250 births (Centers for Disease Control and Prevention, 2003). This means that as many as 1.5 million Americans today are believed to have some form of autism.

And that number is on the rise. Based on statistics from the U.S. Department of Education and other governmental agencies, autism is growing at a rate of 10-17 percent per year. At these rates, the ASA estimates that the prevalence of autism could reach 4 million Americans in the next decade.

The overall incidence of autism is consistent around the globe, but is four times more prevalent in boys than girls. Autism knows no racial, ethnic, or social boundaries, and family income, lifestyle, and educational levels do not affect the chance of autism's occurrence.

From Autism Society of America brochure "What is Autism".

The University of Michigan offers a good introduction to Autism and Pervasive Developmental Disorders.

AUTISM IS TREATABLE: Early diagnosis and intervention are vital to the future development of the child. Special educational programs using behavioral methods have proved to be the most helpful treatment for persons with Autism.

Autism characteristics:

Autism and pervasive developmental disorder-not otherwise specified (PDD-NOS) share many of the same characteristics. Due to the similarity of autism and PDD-NOS, the treatment and educational needs are similar for both diagnoses.