Opinion: The autism numbers

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There’s an information vacuum on autism, and where there’s a vacuum, people tend to rush in with theories, wild or otherwise. No one knows why the numbers of autism cases have risen over the past two decades, and in the absence of well-researched theories, there’s been plenty of space for the vaccination notion to grab attention.

But another thing that happened during this big increase was that diagnosis changed, as well as the definition of autism, which was expanded in ways that were certain to make the syndrome more ‘common.’ For example, in some of the most severe autism cases, there’s also mental retardation. A generation ago, doctors would diagnose the retardation and ascribe social and communication problems to that. Doctors and researchers know this is a big part of the picture, but they suspect it’s not the only one.

These days, there’s also some purposeful misdiagnosis that tends to boost autism’s numbers: Parents of children with severe developmental problems seek an autism diagnosis because, as a recognized disability, it’s a ticket to social services. There’s no doubt the kids need the services, but there are some skewed numbers here. One researcher said that when his institute re-examined children who had been diagnosed with autism, they found the condition had been overdiagnosed about 15% of the time.

It’s also unclear whether autism rates have continued to climb since 2000, but they’re at least holding steady.