A new round of interest in the potential impact of diagnostic changes being proposed for the Diagnostic and Statistical Manual of Mental Disorders, or “DSM”, was sparked last week by a report suggesting that many individuals would likely lose their diagnoses if the defining criteria for autism, Asperger’s disorder and Pervasive Developmental Disorder Not Otherwise Specified are changed. A number of the stories that we were seeing suggested that the definition was being tightened because of concerns relating to over-diagnosis, with one commenter offering that the change in definition would solve the autism epidemic by “nipping it in the bud”.

As one who has been directly involved in the DSM process and whose fingerprints are on some of these proposed changes, I have been asked to clarify what is going on and thought it might be helpful to share some thoughts here. 

The DSM workgroup responsible for moving forward potential changes in the definition of autism is composed of clinician scientists like myself who have devoted our professional careers to people affected by autism and related conditions, and we would never sign on to a plan aimed at manipulating the numbers of people diagnosed because of a perception that there were too many. If there was a flu epidemic, we wouldn’t change the definition of the flu, we would try to get to the bottom of the cause of the epidemic.

The reason to take a careful look at the definition of autism is two-fold:  first, the entire DSM is being revised—as has happened before (this will be the 5th Edition)—so there is an opportunity to review everything including autism.

Second, we have learned a lot about autism and related conditions in the nearly two decades since the last edition of the DSM, and that knowledge should inform how the diagnosis of autism is made.

For example, Rett’s Disorder was introduced in the last edition of the DSM as one of the Pervasive Developmental Disorders. Since that time, we have learned the genetic cause of this disorder, and as is true for Fragile X Syndrome (for which there is also a known genetic cause), some children with Rett’s and Fragile X syndromes may develop an autism spectrum disorder, but neither Rett’s Disorder nor Fragile X Syndrome are “pervasive developmental disorders”. Thus, in the DSM 5, we are proposing that Rett’s Disorder no longer be listed as a type of autism. It is a unique condition.

The other types of autism, namely Asperger’s Disorder and Pervasive Developmental Disorder Not Otherwise Specified, also need to be changed. I’ll highlight the rationale for those changes and also walk through the rationale for the changes we are proposing to the definition of autism in my next installment. Stay tuned.

Part 2