Simply Explaining, Explaining Simply: Autism Spectrum Disorder

Autism Spectrum Disorder

DSM V Diagnostic Criteria

A. Persistent deficits in social communication and social interaction across multiple contexts, as manifested by the following, currently or by history:

  1. Deficits in social-emotional reciprocity.
  2. Deficits in nonverbal communicative behaviours used for social interaction
  3. Deficits in developing, maintaining, and understanding relationships.

B. Restricted, repetitive patterns of behaviour, interests, or activities, as manifested by at least two of the following, currently or by history:

  1. Stereotyped or repetitive motor movements, use of objects, or speech.
  2. Insistence on sameness, inflexible adherence to routines, or ritualized patterns of verbal or nonverbal behaviour.
  3. Highly restricted, fixated interests that are abnormal in intensity or focus.
  4. Hyper- or hyporeactivity to sensory input or unusual interest in sensory aspects of the environment.

C. Symptoms must be present in the early developmental period (may not become fully manifest until social demands exceed limited capacities, or may be masked by learned strategies later in life).

D. Symptoms cause clinically significant impairment in social, occupational, or other important areas of current functioning.

E. These disturbances are not better explained by intellectual disability (intellectual developmental disorder) or global developmental delay.


  • prevalence in the U.S is 11.3/1,000
  • male:female ratio is 4:1
  • immigrants may be more affected

Risk Factors:

  • high recurrence risk for siblings: 2-19%
  • closer spacing of pregnancies
  • advanced maternal or paternal age
  • extreme prematurity (<26weeks)
  • family members with learning problems, social disability, psychiatric disorders

In the Community Setting, once there is reason for concern particularly >18 months of age, use MCHAT (individual and parents) from 6-30 months (2.5years) of age.

Also use the infant-toddler scale for 6-24 months (2 years) of age.–DEVELOPMENTAL%20DELAY%20&%20AUTISM–CCBS%20DP%20Infant-Toddler%20Checklist.pdf

An official diagnosis is often not made until 2-3 years of age.

Keep in mind delayed developmental milestones or regression of developmental milestones.

If deemed to be at high risk, referral to a developmental pediatrician is made where an official diagnosis would be made following an assessment with a multidisciplinary team (i.e., Developmental Paediatrician, Speech and Language Pathologist). An ADOS is used for this assessment, following a series of interview questions and observation of the child’s behaviours and interactions.

There may also be other concerning features, for example, focal neurological signs, seizures, dysmorphic features. Particularly, a family history of developmental concerns or genetic conditions as well as consanguinity become important to consider.

In these situations, consider chromosomal microarray (with appropriate counselling provided), referral to neurologist (with possible EEG and MRI ordered), and consider referral to geneticist.

The earlier the diagnosis is made, the earlier the ABA treatment can be started. In the interim, there are services the child can start going to available in the community for those with developmental concerns (i.e., delayed speech or motor milestones).

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