Is there an autism epidemic?

Reports of an autism epidemic are not substantiated by data, according to Paul Shattuck, a researcher at the University of Wisconsin-Madison’s Waisman Center. Shattuck analyzed statistics from the U.S. Department of Education compiled from 1993 to 2003, according to which there was a 657% increase in autism across the country.

As Susanne Rust reports in the Milwaukee Journal-Sentinel (April 2, 2006):

Shattuck discovered that, at least in most cases, the numbers are not only misleading, they’re likely inaccurate. On one hand, they don’t support a dramatic increase in autism prevalence, but on the other, the figures could be underestimating the absolute number of children with the condition.

Prior to the early 1990’s, the U.S. Department of Education did not have an autism classification for special needs children, so autistic children were previously often classified with other disorders.

A common hypothesis–misconception?–for the dramatic increase in autism is that it is because we know more about autism that it is diagnosed more often.

But Shattuck’s research further suggests that we may actually be under-diagnosing the amount of children with autism. Shattuck suggests that we need different kinds of data to accurately estimate the prevalence of autism which, in special education counts, is calculated by dividing the number of autistic students by the total number of students in a given geogrphic region.

Rust notes that “This means, among other things, that data collected in this manner often underestimate ‘the true population prevalence because, for instance, schools do not go out into the community and actively seek out and evaluate all kids for autism,’ Shattuck said.”

Shattuck’s research shows that a true understanding of autism is crucial to accurately counting the number of persons with autism–and how very far from this we are.