Continuity and Change in Cognition and Autism Severity from Toddlerhood to School Age.

Morrison et al. (2017) followed a small group of toddlers who had an autism diagnosis.

They checked each child again when the kids reached school age.

The team looked at two things: whether the children still met autism criteria and how their thinking skills had changed.

Most toddlers kept the autism label: 73 percent still scored in the ASD range on the ADOS.

Yet cognitive delays shrank fast.

Two-thirds had intellectual disability as toddlers, but only 8 percent still did by school age.

Kantzer et al. (2018) saw the same pattern in a bigger group: about 8 in 10 toddlers who first screened positive kept an ASD diagnosis two years later.

Dellapiazza et al. (2024) add a twist. In 575 children, 29 percent got better at social-communication, but 22 percent got worse overall.

The papers look opposite, but they measure different things. E et al. count who still meets any ASD criteria; Florine tracks how severe the symptoms are. Both can be true: most kids stay autistic, yet half move up or down the severity scale.

Solomon et al. (2018) explain why. They mapped four IQ paths: one-third of autistic kids gained more than 30 IQ points, while one-quarter lost ground. The wide spread hides behind the average gain E et al. report.

Keep the diagnosis, but expect big jumps in thinking and language. Re-test cognitive level before every IEP renewal. A child who scored in the intellectual disability range at age three might test in the low-average band by second grade, so goals, placement, and service minutes may all need a fresh look.