The likelihood of a child’s being given a diagnosis of autism, Asperger syndrome or a related disorder increased more than 20 percent from 2006 to 2008, according to a report released on Thursday by the Centers for Disease Control and Prevention.
“This is a fourfold difference,” Dr. Éric Fombonne, a psychiatrist at McGill University and Montreal Children’s Hospital, said in an e-mail. “It means that ascertainment is unequal across states. Thus, in the next surveys, as ascertainment will most likely improve where it is currently low, average rates are bound to increase. Is there, in addition to this, a real increase in incidence? It’s possible, but cannot be determined from the study design.”