• Autism

What is Autism Spectrum Disorder?


Autism Spectrum Disorder (ASD) is a complex developmental disability that impacts the developing child across a number of critical domains.  More specifically, individuals with ASD present with significant social interaction and communication challenges.  They also tend to display restricted, repetitive behaviours.  Symptom expression can range from mild or subtle to severe and obvious.  It is for this reason that Autism is considered a Spectrum Disorder.

Research suggests ASD is rooted in early brain development and that symptoms/characteristics tend to emerge before the child’s third birthday.   A number of factors that negative impact brain development have been linked to ASD (e.g., genetics, neuropathology, metabolic conditions, etc.).


Currently, there is no definitive medical test, such as a blood test, to identify ASD. Rather, professionals rely on established behavioural criteria. Generally those with ASD display the following [from the Diagnostic and Statistical Manual of Mental Disorders – Fifth Edition] (DSM-V) (American Psychiatric Association, 2014).


Deficits in social communication and social interaction as manifested by:


  • Deficits in social-emotional reciprocity
  • Deficits in nonverbal communicative behaviours used for social interaction
  • Deficits in developing, maintaining, and understanding relationships


Restricted, repetitive patterns of behaviour, interests, or activities, as manifested by:


  • Stereotyped or repetitive motor movements, use of objects, or speech
  • Insistence on sameness, inflexible adherence to routines, or ritualized patterns of verbal or nonverbal behavior
  • Highly restricted, fixated interests that are abnormal in intensity or focus
  • Hyper-or hypo-reactivity to sensory input or unusual interest in sensory aspects of environment

In addition to the criteria listed above, there are a number of other characteristics associated with ASD. However, these characteristics do not have to be present for the diagnosis to be made.  These include:


  • intellectual impairment
  • abnormalities of mood
  • short attention span / impulsivity
  • an uneven profile of skill development
  • abnormalities in eating, drinking or sleeping
  • unusual fears or anxieties


Although ASD was once considered a relatively rare disorder, it has become a pressing health care issue. Reported prevalence estimates range from 0.7/10,000 to 264/10,000, when data is combined it suggests approximately 66 out of every 10,000 people has ASD.  Given this statistic, it is likely that most Canadians will encounter an individual with ASD at some point during their life.