Autism diagnoses may decrease with the application of new diagnostic criteria, according to a new nation wide study led by researchers at the Center for Disease Control and Prevention’s National Center on Birth Defects and Developmental Disabilities in Atlanta. The study indicates that as many as 19 percent of children currently diagnosed with autism would not receive the diagnosis under the new criteria.
The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), published in May, 2013, contains the checklist of symptoms that are to be met in order to be diagnosed with Autism Spectrum Disorder (ASD). Researchers working on this new study used this checklist to assess 6,577 8-year-old children from 14 states around the country who had already been diagnosed with autism between 2006 and 2008 using criteria from a previous edition of the DSM, the DSM-4. They determined that only approximately 81 percent of those children would be diagnosed as autistic if evaluated using the new criteria today.
The DSM-5 uses 7 criteria for diagnosis, as opposed to the DSM-4’s twelve. In addition, the DSM-5 does not separate out sub-types of autistic disorders such as Asperger’s, as the DSM-4 did. The DSM-5 uses the diagnosis of ASD to cover all of the previously separated diagnoses falling under the “umbrella” of autism.
Researchers indicated that those children who had previously been diagnosed with autism that also had an intellectual disability and required special education classes were more likely to remain diagnosed under the new criteria, as were children who had experienced a “history of developmental regression.” They also reported that many of those who appear as though they may not be diagnosed under the new criteria missed the diagnosis narrowly, by only one symptom.
Those working on this study that seems to show that autism diagnoses may decrease with application of the new diagnostic criteria have been quick to assure those already diagnosed with autism and their loved ones that this work will not result in a reversal or loss of an existing diagnosis. The study is intended to examine the way in which children are evaluated by professionals when presenting with possible indicators of autism. In addition, the basic signs looked at as possible warning signs of autism have not changed.
The impact may not be quite as great as it first appears from this study either, according to lead researcher on the project, Matthew Maenner. He acknowledged that the fact that they were “looking backwards in time” could be somewhat problematic, as it does not take into account changes in actual diagnostic process over time. In addition, there may be more emphasis on the symptoms that receive increased importance in the DSM-5 as clinicians begin to apply the new criteria, which might lessen the difference in diagnostic numbers seen in this study going forward. Finally, evidence of those symptoms that receive more emphasis in the DSM-5 may have been present among those previously diagnosed, but may not have been recorded at the time of their previous evaluation because they were not indicated as criteria to focus on at the time.
More research as to the application of the new criteria is expected and is needed before any definitive conclusions as to its potential to decrease the number of autism diagnoses are reached.
By Michele Wessel