The term Autism Spectrum Disorders (ASD) is used to refer to a range of related conditions also known as Pervasive Developmental Disorders (PDD). Autistic disorder and these related conditions are lifelong developmental disabilities that usually begin during the first three years of a child's life. The earlier a child receives intervention the more gains they make.
What are Autism Spectrum Disorders (ASD)?
The term Autism Spectrum Disorders (ASD) is used to refer to a range of related conditions also known as Pervasive Developmental Disorders (PDD). Autistic disorder and these related conditions are lifelong developmental disabilities that usually begin during the first three years of a child's life. The earlier a child receives intervention the more gains they make.

PDD are neurologically based disorders and affect the way a child communicates, interacts with other people, and perceives and reacts to the world. The current prevalence rate is believed to be between 1/166 to 1/500 and is more common in boys than girls.