Autism spectrum disorders (ASDs) are complex neurodevelopmental disorders characterized by qualitative impairments in three domains: social interaction, communication, and repetitive, stereotyped behaviour. ASDs can have a negative impact on the well-being of affected individuals^*.  These symptoms often begin by the age of three years, and persist throughout the life span. 

Autism is often referred to as a “spectrum disorder,” meaning that its symptoms and characteristics can present themselves in a variety of combinations, ranging from mild to quite severe.

The phrase “Autism Spectrum Disorders (ASD)” refers to a broad definition of autism including the classical form of the disorder as well as Pervasive Developmental Disorder Not Otherwise Specified (PDDNOS), Rett syndrome, Asperger syndrome, and Childhood Disintegrative Disorder.