The prevalence of autism spectrum disorder (ASD) has increased over the past two decades from 0.6% in 2000 to 2.3% in 2018. With this increase in prevalence, has there been a change in the proportion with intellectual disability? Shenouda et al (10.1542/peds.2022-056594) share with us an analysis from an active ASD surveillance program that is part of the CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network, from 2000-2016.
Overall, there were more than 4,600 8-year-olds with ASD in this study, of whom 32.3% (n=1505) had intellectual disability. Over the 16 years of the study, the proportion with intellectual disability doubled and the proportion without intellectual disability increased 5-fold.
This study also reports demographic differences in the proportion with intellectual disability during the study period. For example, non-Hispanic Black children compared with non-Hispanic white children were more likely to be identified with autism with intellectual disability especially when living in non-affluent areas over the decade and a half studied. Alternatively, Black children with autism without intellectual disability were less likely to be identified compared to non-Hispanic white children. In addition, children living in more affluent areas were more likely to be identified with autism without intellectual disability compared to children living in less affluent areas. What might be contributing to these differences?
To answer this question, we invited Dr. Emily Hotez from UCLA and Dr. Lindsay Shea from Drexel University to share their thoughts in an accompanying commentary (10.1542/peds.2022-059541). They point out the importance of underlying social determinants of health leading to these findings. Drs. Hotez and Shea stress the importance of detecting and addressing negative social determinants of health for all children. Link to this important study and commentary to learn more.