Testing for autism
Autism spectrum disorder (ASD) affects about 1 in 68 children and can have a profound impact on a person’s quality of life. As of such, it is important to correctly diagnose those who are on the autism spectrum and to conduct further research on this disorder. Currently, the “golden standards” for assessing children with ASD are the Autism Diagnostic Interview-Revised (ADI-R) and the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2). The ADI-R is a structured interview conducted with the child’s caregiver and given by a trained clinician, and the ADOS-2 is a semi-structured protocol conducted with the child. Although they are considered the “golden standards”, there are actually quite a few issues with these tests, with consequences on both research and diagnosis of ASD.
One of the issues with these two tests is the presence of confounding factors such as IQ. Indeed, lower IQ has been associated with lower scores on most behavioural measures, and considering that ASD is often comorbid with intellectual disabilities, it might be difficult to disentangle the effects of each disorder on the test results. This is an issue in research, where it is often necessary to compare patients who are similar in the severity of their disorder, but the influence of IQ on the results makes it difficult to determine where they are situated on the autism spectrum. Another research related issue with these tests is that they demand a lot of resources. Indeed, test administrators have to be trained and the 2 tests take a total of 3 hours to administer. As of such, research on ASD is slowed down and doctorate students may be deterred from conducting research on this subject.
In the clinical setting, these 2 tests pose some issues that can affect the diagnosis of a patient. In 2013, DSM-5 made the notable change of replacing the diagnosis of “autistic disorder”, “Asperger’s syndrome”, and “PDD-NOS” with the single category of “autism spectrum disorder”. This was meant to reflect the shared view that autism can occur in various forms, and that there exist cases of mild autism. Unfortunately, the ADI-R only tells you if someone has ASD or not, and does not distinguish milder forms of autism. This is problematic, because it means that some people with mild autism might also be diagnosed as being normal, and therefore not be given access to all the resources that they actually need. Furthermore, it is often up to the clinician’s judgment to interpret the results and determine where the child stands on the spectrum. However, as seen in class, clinicians are actually not very accurate in their judgments, due to the fact that they do not use the same predictors and weightings consistently. It might therefore be worthwhile to review these tests so that they can distinguish milder forms of autism, and to incorporate more statistical methods in the diagnosis.
