Disparities in Intellectual Disability in Autism Spectrum Disorder: A call for the immediate need for more resource

Richard E Frye, MD, PhD
Autism Discovery and Treatment Foundation, Phoenix AZ
Rossignol Medical Center, Phoenix AZ

A new publication in the journal Pediatrics examined the change in rates of autism spectrum disorder (ASD), particularly with respect to those with intellectual disability (Shenouda et al., 2023). This study was performed by examining data collected as part of the CDC – Autism and Developmental Disabilities Monitoring Network in four counties in New Jersey which represented a diverse population in the New York-New Jersey Metropolitan Area over a six-year period from 2000 to 2016. Not surprisingly, the overall ASD rates increased but particularly interesting was that fact that there was an overall increase in the proportion of children with ASD who did not have intellectual disability. However, there was a greater proportion of children with ASD without intellectual disabilities in more affluent areas while there was a relatively greater portion of children with ASD who also had intellectual disability in underserved areas with low socioeconomic status. The authors believe that this disparity was due to the underdiagnosis of children without intellectual disability in underserved areas due to lack of early diagnosis and treatment. Of course, this is an important reminder of the health disparities that affect the effective care of children.

One of the limitations in this and other research examining intellectual disability is ASD is the ability to measure intellect. I have many parents with children in my practice that tell me how smart their children are despite having an evaluation that suggest intellectual disability. There are many reasons for this. It is well known that intelligence quotient (IQ) tests have a high language load, meaning that having language problems will underestimate intelligence. Indeed, older studies suggests that a standard IQ test would categorize 20% more children with ASD as low functioning (Dawson et al., 2007) or underestimate IQ by 21 points (Grondhuis and Mulick, 2013) and more recent studies have supported this notion (Al-Mamari et al., 2021; Giofrè et al., 2019). Furthermore, the reduced ability to communicate non-verbally with gestures, the limited ability to pay attention and behavioral dysregulation can all interfere with intelligence testing, thus underestimating intelligence. Interestingly, a recent functional MRI studies looking at brain pathways with children with ASD found that many children with ASD had the required language and cognitive pathways intact in the brain, but for some reasons they weren’t utilize these brain pathways, leaving them in a “locked-in” state (Pines et al., 2021). Perhaps there is someway to unlock this cognitive potential.

Research into how to communicate with children with ASD who have communication difficulties is lacking. These techniques for improving communication don’t have to be high tech. For example, the intelligence and creativity of many children with ASD has been revelated utilizing a low-tech alphabet board for spelled communication. Many states do not fund effective augmentative and alternative communication devices which can substantially improve the ability of children with ASD to communicate. Still, we find other children with ASD love music and engage with language is song. Music therapy has been shown to be improve many core symptoms of ASD including verbal and non-verbal communication skills (Geretsegger et al., 2014), yet it is underutilized and underfunded. Indeed, aggressive behaviors, which are commonly treated with pharmaceuticals, are many times a consequence of language impairment and an inability to communicate (Posar and Visconti, 2021). Additionally, improvements in ASD symptoms have been linked to improvement in IQ (Sigman and McGovern, 2005; Turner et al., 2006). Thus, improving communication and other symptoms in ASD can have a profound impact on the lives of children with ASD and their families as well as uncover intelligence that is otherwise unappreciated.

Clearly, children with ASD require additional resources. While the lack of resources in low socioeconomic areas may contribute to a lack of early identification of children with higher functioning children with ASD, it may also explain the higher levels of intellectual disability as less resource for intervention will leave children in a more vulnerable state and missed habilitating children for them to a attain their optimal outcome. This is truly a lost opportunity Unfortunately, much of the federally funded research into ASD targets very basic biological mechanisms instead to targeting potentially high-impact, practical treatments.  Thus, this disparity data may be point to that fact that we need to find innovative ways for all children with ASD to attain their full potential and allocate the necessary resources to diagnosis and intervene early and continuously into adolescence and adulthood. 

References

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