How Common is Autism?

In 2012, the Centers for Disease Control and Prevention’s Autism and Developmental Disabilities Monitoring Network reported that approximately 1 in 88 children in the United States has an Autism Spectrum Disorder. This represents an increase in the prevalence of autism spectrum disorders compared to earlier in the decade when prevalence was cited as 1 in 110 and 1 in 166. In the 1980’s autism prevalence was reported as 1 in 10,000. In the nineties, prevalence was 1 in 2500 and later 1 in 1000. It is problematic to compare autism rates over the last three decades, as the diagnostic criteria for autism have changed with each revision of the Diagnostic and Statistical Manual (DSM). In 1983 the DSM did not recognize PDD-NOS or Asperger's syndrome, and the criteria for autistic disorder (AD) were more restrictive.

ASDs are almost 5 times more common among boys (1 in 54) than among girls (1 in 252) and they are reported in all racial, ethnic, and socioeconomic groups. Studies have been conducted in several continents (Asia, Europe, and North America) that report a prevalence rate of approximately 1 percent. A 2011 study reported a 2.6 percent prevalence of autism in South Korea.