Children diagnosed with ASD as preschoolers may not meet criteria on entering school

More than a third of children diagnosed with autism spectrum disorder (ASD) before three years of age may not meet the criteria by the time they start school, a recently published US study has found.

As a result of the findings, researchers suggest that a more appropriate pathway for children with an early ASD diagnosis may be to monitor children over time to clarify their diagnosis and to adjust treatment recommendations accordingly. 

To reach their findings, researchers tracked a cohort of 213 children who received a clinical ASD diagnosis at 12–36 months of age and were then re-assessed at age 5–7 years of age.

They found that 37 per cent of toddlers diagnosed before the age of three years are unlikely to meet the criteria for ASD by school age, and ‘higher baseline adaptive functioning’ and gender are linked with non-persistent ASD diagnoses.

ASD expert Dr James Best said while the research produced some interesting findings, its interpretation requires caution.

“If approximately a third of people who receive a diagnosis early are then being re-assessed and not maintaining that diagnosis for ASD later on, that could be misinterpreted as having to be wary about early diagnosis,” he said.

Dr Best hopes that the research will be interpreted correctly “because my feeling is it is more important that we don’t miss diagnoses and preferably get them early, and if you get a diagnosis and then lose it, it’s actually not a loss.”

“It may well be that both the diagnosis and re-diagnosis, or lack of diagnosis, were both accurate,” he added. 

“Especially with the impact of early intervention, it may mean that children early on do meet the criteria, but within dimensions that their autistic traits are impacts and it is no longer necessarily a disorder that is requiring help of some degree.”

Despite the findings, Dr Best said missed diagnoses should remain the focus.

“My concern is that we don’t miss diagnosis and have late diagnoses – that’s more important than having early diagnoses that probably are appropriate at the time,” he said.

To access the findings in full please see here.