Does the Age of Diagnosis of Autism Contribute to Differential Cognitive and Behavioral Outcomes during Middle Childhood?

Background: Early diagnosis of Autism Spectrum Disorders (ASDs) is now considered best practice so that children may access early intervention (EI) in a timely manner. However, the majority are diagnosed after 3-years.

Objectives:  The aim in the current study was to establish whether the developmental outcomes at school age differ as a function of the age when children are diagnosed with ASD.

Methods: The cognitive, behavioural and adaptive outcomes of children diagnosed with ASD at 24-months (n=48) was compared to outcomes in a group of children diagnosed after 3-years and prior to school entry at 5-years (n=37). All children were aged between 7- to 9 years at follow-up.

Results: Children diagnosed early had received more intervention than those diagnosed later, and had significantly better verbal abilities and overall cognitive abilities at school age. A greater percentage of these children were in mainstream schools and significantly fewer received ongoing support compared to children in the late diagnosis group. However, no differences were found between groups in adaptive behaviour or autism severity scores at school age.

Conclusions: The findings support the importance of diagnosing ASD early, which maximizes children’s opportunities to receive EI, leading to improved outcomes at school age