Differentiation of children with varying levels of autism spectrum disorder symptoms from children developing typically

The DSM-5 (American Psychiatric Association, 2013) combined all previous autism diagnoses into a single diagnostic category, autism spectrum disorder (ASD). The present study examined whether an 84-item measure of the ASD DSM-5-TR (2022) criteria, the Coolidge Autism Symptom Survey (CASS), could differentiate between children who were developing typically (DT) and children diagnosed with mild, moderate, and severe levels of ASD. One-hundred forty-nine adult participants completed the CASS about a child (5-17 years old) they knew well. As hypothesized, DT children scored significantly lower on the CASS than children with mild, moderate, and severe ASD. The CASS sums on the latter two groups were not significantly different. The results preliminarily support the reliability and validity of the CASS.