Parent-reported early symptoms of autism spectrum disorder in children without intellectual disability who were diagnosed at school age

To identify characteristics of children whose autism spectrum disorder might not be diagnosed during toddlerhood, this study used archived Autism Diagnostic Interview-Revised records to examine the historical presentation of autism spectrum disorder symptoms in 48 school-age children with autism spectrum disorder.

Children diagnosed after starting school (Late-Diagnosed; n = 24) were compared to age-matched children diagnosed before school age (Early-Diagnosed; n = 24). Symptom presentation was similar between groups, with the Late-Diagnosed group exhibiting only marginally fewer symptoms historically. The most commonly reported historical symptoms were negative symptoms, namely, deficits in social behaviors.