There has been a major increase in the incidence of autism over the last 20 years, yet many children who have autistic traits still go undiagnosed clinically and thus don't receive the support they need through educational or health services.
In recent studies these undiagnosed children have been included in estimates of how many children have autism spectrum disorder (ASD), which includes both autism and Asperger's syndrome. Such studies have estimated that one in every 100 children has an ASD.
A study published in a recent issue of the Journal of Child Psychology and Psychiatry found a large number of undiagnosed children displayed autistic traits: repetitive behaviors, impairments in social interaction and difficulties with communication. These traits were at levels comparable to the traits displayed by children who had a clinical ASD diagnosis, all of whom diagnosed between the ages of 1 and 12. However, the undiagnosed children were not deemed eligible for extra support at school or by specialized health services.
The lead researcher of the study, Ginny Russell, writes, "ASD diagnosis currently holds the key to unlocking intervention from school systems and health programs. Perhaps these resources should be extended and available for children who show autistic impairments but remain undiagnosed."
Russell points out that the study also shows there is a gender bias in diagnosing children with ASD: Boys are more likely to receive a diagnosis than girls, even when they display equally severe symptoms.