Autism Cases on the Rise; Reason for Increase a Mystery:

Scientists are scouring genetic and evironmental data to find a cause for the rise in autism.

The number of children diagnosed with autism or related disorders has grown at what many call an alarming rate. In the 1970s and 1980s, about one out of every 2,000 children had autism.

Today, the CDC estimates that one in 150 8-year-olds in the U.S. has an autism spectrum disorder, or ASD. This expanded definition refers not only to autism but also to a collection of brain development disorders such as Asperger's syndrome and a condition known as pervasive developmental disorder -- not otherwise specified (PDD-NOS). Though all the disorders share some symptoms, they are different in other ways, including the timeline of symptoms and the severity, according to the CDC.

In 2023, the CDC reported that approximately 1 in 36 children in the U.S. is diagnosed with an autism spectrum disorder (ASD), according to 2020 data.
Boys are four times more likely to be diagnosed with autism than girls.
Most children were still being diagnosed after age 4, though autism can be reliably diagnosed as early as age 2.
31% of children with ASD have an intellectual disability (intelligence quotient [IQ] <7, 25% are in the borderline range (IQ 71–85), and 44% have IQ scores in the average to above average range (i.e., IQ >85).
Autism affects all ethnic and socioeconomic groups.
Minority groups tend to be diagnosed later and less often.
Early intervention affords the best opportunity to support healthy development and deliver benefits across the lifespan.
There is no medical detection for autism.