Autism spectrum disorders (ASD) are lifelong neurological disorders that affect a person’s development and how the brain processes information. Autism and related disorders are characterized by challenges in communication, social interaction and unusual behaviour, interests and activities. Spectrum disorders mean that symptoms can be present in a variety of combinations and can range from mild to severe.

Autism is a form of pervasive development disorder (PDD), meaning it can affect all areas of a person’s development. Other pervasive development disorders include Rett‘s disorder, childhood disintegrative disorder, Asperger‘s disorder, and PDD not otherwise specified (PDD-NOS). Autism can co-exist or may share common features with other conditions.

A diagnosis is often a multi-step process which may include a psychiatrist, clinical psychologist, neurologist, developmental pediatrician, speech/language pathologist/therapist, occupational therapist, teacher, or other health professionals. Often, related assessments are done in order to develop appropriate programming. Some assessments are done during the diagnostic process while others may occur prior to or after diagnosis.

For most individuals with autism, there appears to be a genetic factor as well as environmental triggers. It has been shown that people with autism have differences in brain structure and chemistry and the reasons for these differences are being investigated.

Often, autism is accompanied by other physical symptoms, the causes of which are not fully understood.

ASDs are an increasingly common disorder. The current estimate of frequency for autism is 1 in 1,000 (and up to 1 in 166 when all ASDs are included).