Members of the committee tasked with updating the diagnostic criteria for autism appear to be digging in as critics worry that proposed changes will strip many of their diagnosis.

In a commentary released this week, members of the American Psychiatric Association panel charged with revising the autism definition appearing in the forthcoming edition of the Diagnostic and Statistical Manual of Mental Disorders, or DSM, defended the changes they’re proposing.

Specifically the work group has recommended that several labels including Asperger’s syndrome and pervasive developmental disorder, not otherwise specified be folded into an umbrella diagnosis of “autism spectrum disorder.”

However, many in the autism community became alarmed about the changes in January when a group of Yale University researchers reported that an analysis they conducted found that a significant number of people currently diagnosed with autism could be left out under the new criteria.

In response, thousands signed an online petition asking the American Psychiatric Association to reconsider, as parents and advocates worried that the diagnostic changes could leave many without needed services.

Nonetheless, the committee continues to defend its proposal and in a commentary appearing in the April issue of the Journal of the American Academy of Child & Adolescent Psychiatry the group criticized the methods used in the analysis released early this year. Specifically, the committee faults the research for relying on data collected in the early 1990s and said that the findings “justify neither alarming headlines nor dramatic conclusions.”

Any change to the autism definition in the DSM could have huge implications. The book is relied on by everyone from mental health professionals to researchers and insurers.

The American Psychiatric Association, which publishes the DSM, says that preliminary results from field tests it conducted of the proposed changes are finding the criteria to be “both sensitive and specific.”

The organization has agreed, however, to open up an additional public comment period on the issue this spring.

“We remain open to any concerns the academic and advocacy communities might have, but we strongly support the decisions that these leading researchers and clinicians have made,” said David Kupfer, chair of the DSM-5 Task Force, in a statement this week. “The proposed ASD criteria are backed by the scientific evidence.”

The fifth edition of the DSM is expected to be published in May 2013.

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