A new commentary emphasizes the importance of a multidimensional definition of autism severity — including intellectual disability and functional impairment — but stops short of proposing a specific scheme
Image by NCSA based on ideas contained in the commentary in Autism Research.
By Jill Escher
While neurodiversity advocates often like to say there’s no such thing as autism severity, a group of prominent researchers have published a new commentary taking the opposite point of view.
Published in the journal Autism Research, “Autism severity and its relationship to disability” (open access at https://onlinelibrary.wiley.com/doi/10.1002/aur.2898), researchers Einat Waizbard-Bartov, Deborah Fein, Catherine Lord, David Amaral emphasize that not only is autism severity measurable according to the DSM-5 domains of social-communication and repetitive behaviors, the severity is dependent on many other real-world dimensions that should also be considered.
These dimensions include intellectual ability, adaptive functioning (daily living skills) expressive and receptive language, anxiety, irritability, sleep disorders and more. These and other dimensions can have a tremendous impact on their clinical and support needs.
This “multidimensional approach” would be “useful for identifying subgroups of individuals as well as for determining individual needs and strengths in clinical assessments.” The DSM-5’s three levels of severity are too narrow, they say, and are “not sufficient to closely map on to an individual's real-life functioning, including their experiences and challenges.”
The commentary is the latest in a long debate among researchers and clinicians about how to subgroup different types of autism, which as present is so vastly heterogenous that it includes PhD professors with social awkwardness and those with IQs of 30 and daily living skills below a toddler level. The researchers caution against “studying autism spectrum disorder (ASD) as a single syndrome,” which has led both clinical care and research away from directions that may be more productive.
They note that the majority of individuals with autism are also diagnosed with other conditions such as intellectual disability, adaptive skills, language impairments, sleep disorders, gastrointestinal symptoms, anxiety, depression, aggression, motor abilities and more that standardized assessments for autism were not designed to measure. But the authors urge a move toward a more pragmatic approach. “[I]n the context of functional outcomes and well-being, these co-occurring conditions can greatly impact the way the core symptoms are manifest in an individual's behavior, as well as the extent to which autism impacts functioning in everyday life,” they write. Assessments must do a better job to “provide a full picture of the challenges” to improve identification of needs, interventions, supports, and future goals, in addition to research efforts.
They note that measurements of adaptive skills may be more highly correlated with cognitive functioning than with DSM-5 autism symptom severity and that adaptive skills tend to be lower than might be predicted by IQ in autistic individuals.
That said, severity of autism traits alone is a major driver of quality of life. Having higher or more severe autistic traits is associated with lower quality of life for adults (citing Capp et al., 2022), children and adolescents (citing Oakley et al., 2021) and preschoolers (citing Lopez-Espejo et al., 2021). However, other factors are also shown to impact quality of life, even after accounting for core autism traits (Oakley et al., 2021).
The authors point to the term “profound autism” as an example of an autism subgroup that is defined beyond the simplistic boundaries of the DSM-5. “For these individuals (and their caretakers), the challenges brought on by having autism are substantial and go well beyond the core characteristics. Having profound autism is impairing to functioning and independence and greatly impacts outcomes. A major advantage of this term is that it integrates both core and co-occurring conditions to represent the real-life challenges of an individual,” they write.
The authors also dismiss critics’ concerns about subgroup-oriented terms like “profound” being stigmatizing. They write that “almost all terms, no matter how gentle can be used to stigmatize. The onus is on us to challenge this stigmatization in whatever form it occurs.”
Despite their enthusiasm for a new multidimensional approach to assessing and categorizing autism severe, the authors did not propose a specific scheme for classifying autism subtypes, saying the “more attainable goal for the near future may be a more universally accepted dimensional characterization of behavior,” citing a similar effort in the real of intellectual disability (Schalock & Luckasson, 2015). The dimensions used in that approach are (a) intelligence, (b) adaptive behavior, (c) health, (d) participation in social activities, and (e) the personal and environmental context in which individuals live their daily lives. For autism severity of social and repetitive behavior symptoms would have to be added.
A new classification system, once developed, would help specify functional levels, operationalize the level of supports needs, define health status, and help determine legal status, they write. But creating a formal definition remains an “unfulfilled challenge.”
Jill Escher is president of the National Council on Severe Autism.
Disclaimer: Blogposts on the NCSA blog represent the opinions of the individual authors and not necessarily the views or positions of the NCSA or its board of directors.