Diagnosis of ASD

Diagnosis of ASD


Diagnosing Autism Spectrum Disorder (ASD) can be difficult since there is no medical test, like a blood test, to diagnose the disorder. Doctors, psychiatrists, developmental pediatricians, and clinical psychologists are professionals who diagnosis ASD. These professionals will follow the Diagnostic and Statistical Manual (DSM) for Mental Disorders, along with the assessment findings from other health care professionals to determine whether a person has an ASD.

There are two categories of criteria used in the ASD diagnosis: social communication/social interaction and restricted, repetitive behaviours/interests.

Within the first category deficits are observed as persistent across multiple contexts, as manifested by all of the following, currently or in the past:

  1. Deficits in social-emotional reciprocity (i.e. the ability to share interests, feelings, one-sided interactions)
  2. Deficits in non-verbal communication behaviours used for social interaction (i.e. the ability to use gestures, make eye contact, etc.)
  3. Deficits in developing, maintaining and understanding relationships

Within the second category, at least two of the following are manifested currently or in the past:

  1. Stereotyped or repetitive motor movements, use of objects, or speech (i.e. hand-flapping, walking on tiptoes, rocking, spinning, echolalia, etc.)
  2. Insistence on sameness, inflexible adherence to routines, or ritualized patterns of verbal or nonverbal behavior (i.e. trouble changing from one activity to another, insistence upon completion of activities in a specific way, avoidance of new things, etc.)
  3. Highly restricted, fixated interests that are abnormal in intensity or focus (i.e. narrower and persist over time compared to their age matched peers)
  4. Hyper- or hypo-reactivity to sensory input or unusual interest in sensory aspects of the environment (i.e. low tolerance for music, loud noises, bright lights, or may seek out input by crashing into walls, squeezing into tight spaces, etc.)

Symptoms must be present in the early development period but may not become fully manifest until social demands exceed limited capabilities or may be masked by learned strategies in later life. This is why, in many cases, your child may seem fine until they begin attending a child care setting or start formal schooling.

Symptoms cause clinically significant impairment in social, occupational or other important areas of current functioning, compared to same age/stage peers.

Other things your child’s clinician may check for include:

  • The presence of an intellectual impairment/disability
  • The presence of a language impairment
  • Other disorders that may also be present, including Attention Deficit Disorder, Obsessive Compulsive Disorder, Tourette Syndrome, or Anxiety Disorder.

In Manitoba, children diagnosed with an Autism Spectrum Disorder (and other disabilities) can be referred to Children’s disAbility Services (Manitoba Department of Families). This service assists families who have children with developmental and/or physical disabilities who have needs that arise from the disability. A Family Services Worker (FSW) is assigned to each child. This individual informs parents of resources and services available to them – including speech therapy, occupational therapy, physical therapy and respite. A FSW will make referrals, answer questions and provide support as needed.

To learn more about Children’s disAbility Services and how referrals to this service are made, visit http://www.gov.mb.ca/fs/pwd/css_answers.html.

*FYI: The DSM-V is a manual that explains all mental health disorders and the criteria individuals must meet in order to be diagnosed with a mental health condition.

Age of Diagnosis

ASD is commonly diagnosed in early childhood between 2 and 3 years of age. However, an ASD can be diagnosed as early as 12 months of age if signs and symptoms are more severe or in later years if signs and symptoms are not as noticeable. Autism Spectrum Disorders are four times more likely to be diagnosed in males than females.

For more information on diagnosis and the assessment process, visit the following websites: