Discovering Autism: Unraveling an Epidemic

First of a four-part series in The Los Angeles Times.

The U.S. Centers for Disease Control and Prevention estimates that nearly 1% of children across the country have some form of autism — 20 times the prevailing figure in the 1980s. The increase has stirred fears of an epidemic and mobilized researchers to figure out what causes the brain disorder and why it appears to be affecting so many more children.
Two decades into the boom, however, the balance of evidence suggests that it is more a surge in diagnosis than in disease.
Factors that have nothing to do with biology can explain much of the steep increase in cases around the world: an expanded definition of autism, spreading awareness of the disorder and an improved ability to distinguish it from other conditions.