Scientists Disagree on Need for Rewrite of Autism Definition

This from On Special Education: 

The author of a study that could result in a change to the definition of autism, one that could exclude many people from being diagnosed as autistic, now says more study is needed before the definition is adjusted.

In a recent piece for New Scientist magazine, Dr. Fred Volkmar of Yale University explains that the current definition of autism was based on a study he did in 1994.

"Controversially, it also included several newly identified disorders such as Asperger's and ... 'pervasive developmental disorder-not otherwise specified' (PDD-NOS), for those who did not quite meet criteria for a full autism diagnosis but needed similar support," Dr. Volkmar wrote.

Those are the very diagnoses that would evaporate if the Diagnostic and Statistical Manual of Mental Disorders is rewritten—which is scheduled for later this year—based on a newer study by Dr. Volkmar.

"It is possible that support for those in need will be hit, particularly in the U.S., where a diagnosis can trigger health insurance. Secondly, such a radical change would make it difficult to interpret the vast body of work done using [the current version of the [Diagnostic and Statistical Manual of Mental Disorders]," he wrote. "In 1993 there were about 390 peer-reviewed publications on autism. Last year over 2,100 were produced."

But Professor Francesca Happé of King's College London writes in the same article that there's good reason for the autism diagnosis criteria to change.

"Anomalies in [Diagnostic and Statistical Manual of Mental Disorders] criteria for autism and other pervasive developmental disorders (PDDs), which includes the subgroups of autistic disorder, Asperger's and PDD-NOS, have led to clinical inconsistency, leading to wide variations in how diagnoses of these are made. One study found it was the clinic attended that best predicted which label was given," she wrote.

Professor Happé went on to say that the goal of the reworked definition isn't to cut people out of an autism spectrum disorder diagnosis.

"We have proposed a new category of 'social communication disorder' for those with some of the difficulties of autism but without rigid and repetitive behaviour—currently poorly described by the very diverse ... category of PDD-NOS," she wrote. "Our aim is to clean up a hard-to-implement and contradictory system. ... We hope the result will be a clearer and simpler diagnostic system, and better recognition and diagnosis for those with autism spectrum disorders across all ages and ability levels."