Diagnosis


Dr. Celiberti talks about diagnosis, treatment, and resources available on this site.

 
 
Research indicates that early diagnosis is critically important. Therefore, parents and caregivers should be aware of some of the earliest signs of autism. Behaviors of concern include:

  • regression (loss of) of previously achieved language milestones, including babbling;
  • lack of pretend play, or even imitative play, such as babbling on a toy telephone;
  • lack of pointing or looking toward where another points;
  • lack of response to one’s name, or decreasing response to name; and
  • lack of pointing to indicate needs and lack of response to pointing behaviors of others.

Once a suspicion is raised, the diagnosis is dependent on further assessment by an individual or team specializing in the diagnosis and treatment of Autism Spectrum Disorder (ASD). There is no single test that is diagnostic of autism. In order to have a diagnosis of Autism, an individual must satisfy the diagnostic criteria outlined in the DSM-5.

 

Historically, the basic triad of impairments underlying Autism has included:

  • impairment of social interaction,
  • impairment of communication, and
  • restricted repetitive and stereotyped patterns of behaviour.

The DSM-5 reduces this triad to a dyad – impairment of social interaction and communication (now be regarded as one combined domain) and restricted repetitive and stereotyped patterns of behaviour (APA, 2011). Click here to read more about the changes to the DSM-5 diagnostic criteria

Although there is a reduction in underlying impairments, the latest diagnostic criteria expands to include five criterion:

  • Criterion A: social communication deficits, consisting of three items, all of which must be met to satisfy this criterion;
  • Criterion B: fixated interests and repetitive behaviours consisting of four items, of which at least two must be met to satisfy this criterion;
  • Criterion C: symptoms existing in early childhood;
  • Criterion D: symptoms impairing functioning; and
  • Criterion E impairments are not better explained by intellectual disability (intellectual developmental disorder) or global developmental delay (APA, 2011; CDC, 2014).

To diagnose ASD, all of the five criteria must be met.

In addition to changes noted above, the DSM-5 incorporated a dimensional assessment approach, allowing clinicians to measure both the presence and the severity of ASD symptoms as: “very severe,” “severe,” “moderate”, or “mild” in the two symptom domains: social communication and fixated interests and repetitive behaviours (APA, 2011). Click here for complete diagnostic criteria

Because the DSM-5 criteria are a description of behaviors, many diagnostic teams will use comprehensive standardized instrument, specifically developed for the diagnosis of Autism, to demonstrate that observed behaviors are clearly in the atypical range. Such instruments might include one or more of the following: The Childhood Autism Rating Scale (CARS), The Gilliam Autism Rating Scale (GARS), or a combination of the Autism Diagnostic Interview- Revised (ADI-R) and the Autism Diagnostic Observation Schedule (ADOS). See First Signs for similar assessment instruments.

Diagnostic teams will also clarify that the observed difficulties are not better explained by a different diagnosis, such as mental retardation, speech and language delay, hearing loss, and others. Finally, a medical evaluation is recommended to determine if there is a specific, diagnosable medical condition that is associated with the autistic behaviors or whether there are medical conditions commonly associated with autism (e.g. seizure disorder) that require further evaluation and treatment. As part of a comprehensive assessment, audiological evaluation is imperative.

There is evidence to support the fact that early intervention has the potential to make a significant difference for a child with and Autism Spectrum Disorder. Therefore, the American Academy of Pediatrics, the Centers for Disease Control, and numerous other organizations supporting early diagnosis and treatment, strongly recommend early autism screening.

References:

American Psychiatric Association (2011). DSM-5 (Retrieved 16.04.13), from www.dsm5.org.

Centers for Disease Control (2014). Diagnostic Criteria for 299.00 Autism Spectrum Disorder (Retrieved 30.11.14), from http://www.cdc.gov/ncbddd/autism/hcp-dsm.html.