Has the Rate of Autism Increased in the U.S.?

According to the new Centers for Disease Control and Prevention (CDC) report, the prevalence of autism spectrum disorder (ASD) has not largely changed from 2 years ago with a rate of 1 in 68 children (1.46%).

The CDC’s first report on ASD prevalence, released in 2007, was based on data from 2000 and 2002. The data showed that 1 in 150 children had ASD. Though rates have been increasing since the 1960s, researchers are not sure if the rise is due to increased ASD diagnoses or if actual cases are increasing, or if the raise is due to a combination of both factors.

In the new report, researchers from the Johns Hopkins Bloomberg School of Public Health reported that boys were 4.5 times more likely to be identified with ASD than girls with 1 in 42 cases among boys, and 1 in 189 among girls. Data was collected from 11 regional monitoring sites included in the Autism and Developmental Disabilities Monitoring (ADDM) Network. In general, researchers did not see a significant increase in the overall prevalence but the disparity among racial and ethnic groups persisted. Dr. Li-Ching Lee, PhD, ScM, cited that in Maryland, “Hispanic children were less likely to be evaluated for developmental concerns and therefore less likely to be identified.”

Most of the children (95%) identified with ASD in Maryland had developmental concern noted in their records by age 3 but only 55% of these children received a comprehensive evaluation by that age. The 6th report by the CDC’s ADDM reported the following estimated prevalence rates:

1 in 68 children in the 2014 report that looked at 2010 data
1 in 88 children in the 2012 report that looked at 2008 data
1 in 110 children in the 2009 report that looked at 2006 data
1 in 150 children in the 2007 report that looked at 2000 and 2002 data

It is too early to determine if the overall prevalence rate has stabilized because the numbers range across the ADDM communities, the researchers concluded. They added that non-white children with ASD are being evaluated at a later age than non-Hispanic white children.

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