About 1 in 68 children in 10 states monitored by the Centers for Disease Control have been identified with an autism spectrum disorder, the highest prevalence of the diagnosis since the CDC first started monitoring this in 2000.
In 2008, the estimate was that approximately 1 in 88 childrenin the monitored states had been diagnosed with an ASD. In 2006 the ratio was 1 in 110, and in estimates for 2002 and 2000, it was 1 in 150.
(A note: disorders such as Asperger syndrome and pervasive developmental disorder have recently been folded into one diagnosis, “autism spectrum disorder,” through a recent revision to the Diagnostic and Statistical Manual of Mental Disorders, also known as the DSM-5.)
The latest estimates are based on information collected from the health and special education records of children who were 8 years old and lived in Alabama, Arizona, Arkansas, Colorado, Georgia, Maryland, Missouri, New Jersey, North Carolina, Utah, and Wisconsin in 2010. They showed a wide variation in prevalance based on geography and demographic factors. For example:
- Boys were almost 5 times more likely to be identified with an autism spectrum disorder than girls—about 1 in 42 boys compared to 1 in 189 girls.
- White children were more likely to be identified with an autism spectrum disorder than black or Hispanic children. About 1 in 63 white children, 1 in 81 black children, and 1 in 93 Hispanic children were identified with an ASD.
- Early identification is still an issue: about 44 percent of children were evaluated for developmental concerns by the time they were 3. Most children were not diagnosed until after 4, though screening tools exist to identify children by age 2.
- The number of children identified with an autism spectrum disorder varied widely by community, from 1 in 175 children in areas of Alabama to 1 in 45 children in areas of New Jersey.
- Black and Hispanic children identified with an autism spectrum disorder were more likely than white children to have an intellectual disability. Previous research has shown that children identified with autism and intellectual disability have a greater number of symptoms and a younger age at first diagnosis. But these new data show that there was no difference among racial and ethnic groups in the age at which children were first diagnosed.
- About 80 percent of children identified with an autism spectrum disorder either received special education services for autism at school or had an ASD diagnosis from a clinician. This means that the remaining 20 percent of children identified with an ASD had symptoms documented in their records, but had not yet been classified as having ASD by a community professional in a school or clinic.
The Centers for Disease Control said it did not know what was driving the increased prevalence, though some of it may be due to the way children are identified, diagnosed, and served in their local communities. The agency has also created a list of developmental milestones that parents and doctors can use to track a child’s development and see if there are early warning signs of autism spectrum disorder.
A version of this news article first appeared in the On Special Education blog.