A Letter from Autism Speaks Chief Science Officer
March 21, 2012
Last month we let you know that Autism Speaks would play a proactive role in monitoring the effect of the planned revisions to the definition of autism and funding research to determine the impact of these changes on affected individuals and their families. These revisions concern the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), scheduled for publication in spring 2013. (See our statement here and answers to frequently asked questions here.)
The proposed revision would fold previously distinct subcategories of autism (Asperger syndrome, PDD-NOS, etc.) into a single category of autism spectrum disorder (ASD). It would do so with a revised set of criteria, or signs and symptoms, for practitioners to use to make a diagnosis.
Many in our community were understandably alarmed by news reports suggesting that these proposed new criteria are likely to exclude many affected children and adults, especially those who are more cognitively able. We share these concerns and have voiced them – clearly and strongly – with those on the DSM-5 committee in charge of these revisions. In particular we pledged to commit our resources to ensuring that all those who struggle with autism symptoms continue to receive the treatment, services and benefits they need – without discrimination.
Today I am pleased to report that we have funded an important new analysis of the revision’s likely impact. This newly funded study will use a large sample of school children recently diagnosed using the old, DSM-IV criteria. The research team – led by Yale child psychiatrist and epidemiologist Young-Shin Kim, M.D., Ph.D. – will reassess this same sample using the proposed DSM-5 criteria. This will provide rigorous scientific information that can help determine whether previously diagnosed individuals would no longer receive an ASD diagnosis under the proposed revision – and why. I will be sure to inform you about the results of this study when they are available.
Meanwhile, we also want to share our perspective on the recently published results of the much anticipated study that set off public concerns in January.
At that time, Fred Volkmar, M.D., director of Yale School of Medicine, told the New York Times that his preliminary analysis suggested that the new criteria would exclude the majority of the “higher functioning” persons on the autism spectrum, including most of those currently diagnosed with Asperger syndrome and pervasive developmental disorder not otherwise specified (PDD-NOS).
Last week, the American Academy of Child and Adolescent Psychiatry published the results of Dr. Volkmar’s study online. His team’s analysis focused on a sample of 933 persons previously evaluated using DSM-IV criteria – 657 of whom having been diagnosed with a disorder on the autism spectrum. The rest were diagnosed with other disorders such as developmental language delay or schizophrenia.
The researchers re-analyzed the records using the proposed new DSM-5 criteria. When all types of autism were included, they found that around 60 percent would have received the new “unified” diagnosis of ASD.
However, this rate varied widely depending on IQ level and original subtype of autism. The proportion of individuals retaining a diagnosis was much higher among those with low IQ (70 or less) than among those with higher IQs. Just over 75 percent of those originally diagnosed with “autistic disorder” met the new criteria for ASD. By contrast, this was true for only 25 percent of those originally diagnosed with Asperger syndrome and 28 percent of those originally diagnosed with PDD-NOS. Most of those who failed to meet the proposed DSM-5 definition of ASD did so because they did not meet criteria in areas of social communication or repetitive behavior.
In terms of strength, the new DSM-5 criteria were excellent at excluding those who did not have an ASD – for example, those with disorders such as developmental language delay.
The number of cases that hypothetically “lost” an ASD diagnosis in this study is indeed worrisome. Wisely, the authors acknowledged a number of significant limitations with the study. In fact, the study raised more questions than it answered. The authors acknowledged that further study is needed to clarify their findings. More reliable information will come from studies that collect data from the community screening rather than just clinical records. Our funding of Dr. Kim’s study is designed to do just that.
We also have a number of other studies in development. They are designed to identify what needs to be changed to ensure that all those who struggle with autism symptoms receive the treatment and services they need. As an organization, we are also dedicated to ensuring that autism is recognized as a lifelong condition with evolving needs for services across the lifespan.
At the same time, we will continue to actively serve as an informational resource and advocate for all members of our community, as they seek to make their needs known and understand how the evolving changes will affect them and their families.
Please help us keep the conversation going. We love hearing from you during our monthly “The Doctors Are In” webchats, in the comment section of our science blog and by email at email@example.com.