How many adults are estimated to have Asperger syndrome in the United States?

An estimated 0.2 percent of the U.S. population is estimated to have some form of Asperger's syndrome based on surveys conducted by the National Institute of Child Health and Mental Development. This is the equivalent of about 1 out of 500 people, states the Asperger/Autism Network.

Males with Asperger syndrome outnumber females by a ratio of four to one. It is necessary for a professional to diagnose Asperger syndrome since there is no single test that confirms the condition. Testing typically involves analysis of behavioral history and observations plus tests of communicative, cognitive and linguistic ability, as the Asperger/Autism Network explains.