In recent years, the number of autism spectrum disorders has increased dramatically in the U.S. The reason for the increase is not fully clear, but it likely due to both improvements and modifications in the diagnostic process that result in an increase in the number of children being identified, as well as some degree of true increase in the incidence of the disorders themselves.
Viimastel aastatel, arv autism on tohutult kasvanud USAs. Suurenemise põhjuseks ei ole täielikult selge, kuid see tõenäoliselt tingitud nii parandusi ja muudatusi diagnostika protsess, mille tulemuseks on suurenenud laste arv on kindlaks, samuti teataval määral tõsi tõusu esinemissagedus häired ise.