Ever since the American Psychiatric Association announced the proposed changes to the definition of autism according to Diagnostic and Statistical Manual of Mental Disorders (DSM), many parents of children with autism spectrum disorders (ASDs) have expressed concern that their child might not meet the new criteria and could therefore lose access to needed services. Recent media reports about DSM-5 have only fueled these concerns by repeatedly (and incorrectly) stating that the reason for revising the criteria is to reduce the number of children diagnosed with ASD. No wonder parents are worried!
The DSM-5 definition of autism is set to debut in May 2013, and the changes are extensive. The most prominent change is the removal of the existing clinical subtypes of autism, such as autistic disorder, Asperger’s disorder and pervasive developmental disorder, not otherwise specified (pdd-nos). In DSM-5, autism spectrum disorder will be used to describe persons affected by autism. Other changes include the reorganization of symptoms and the introduction of new symptoms like unusual responses to the sensory environment (see sidebar for a review of the proposed changes).
Despite what the media may claim, the intention of the DSM-5 committee on Neurodevelopmental Disorders, the special group charged with revising the definition of autism, was not to tighten the diagnostic reins. The revisions were informed by more than 15 years of research— the last version of DSM was published in 1994— and are designed to provide better clarity on what autism is and is not. Most important, the changes are designed to reduce inconsistencies in diagnostic practices among professionals.
Since the arrival of DSM-IV, one of the things researchers have learned is that clinicians are not consistent in how they assign children to the existing categories of autism diagnoses. In fact, a recent study showed that what diagnosis you get, such as autistic disorder versus Asperger’s disorder, is more related to where you go for the diagnosis than to the pattern of presenting symptoms. The changes in DSM-5 will address this problem and thereby make the autism diagnostic process less confusing for parents and other members of the community.
No one disagrees that there is variability in the presentation of autism. To address this fact, DSM-5 will include a severity rating, allowing the diagnosing clinician to specify the level of support that the affected person requires. In addition, unlike in DSM-IV, DSM-5 will allow clinicians to formally specify and diagnose when there are other clinical symptoms of concern like over activity.
Will the new autism definition accidentally leave some affected children out? Our study team recently examined this question using three large data sets of children diagnosed with DSM-IV autism and non-autism disorders. Our results were overwhelmingly positive. When we applied the new criteria to these existing cases, the vast majority of children with DSM-IV autistic disorder, Asperger’s disorder and pervasive developmental disorder, not otherwise specified, met the new DSM-5 definition of autism spectrum disorder. Subgroups of children, such as those younger than age 5, females and children with cognitive abilities in the non-impaired range were also correctly identified using the new criteria.
In the end, the proposed changes will not only make the process of diagnosis smoother for families, but also make a system that allows clinicians to communicate more clearly about the affected child’s needs.
Proposed Changes to the Definition of Autism
- Multiple autism categories to one category. Diagnostic subgroups like autistic disorder and Asperger’s disorder will be dropped. Instead, autism spectrum disorder will encompass everyone with a form of autism.
- Reorganization of symptoms. Symptoms have been reorganized to better represent the research models that show there are two main categories of autism symptoms: impairments in social communication behavior and the presence of restricted and repetitive behaviors.
- New symptoms and dropped symptoms. Language delays, for example, will no longer be considered a core symptom but something that can co-occur with autism. Other symptoms, including sensory interests and aversions, have been added to the criteria.
- Revision of the age of onset requirement. DSM-5 recognizes that not all children show clear difficulties before the age of 3. As a result, the “age of onset before 36 months” has been relaxed.
- Co-occurring disorders may now be diagnosed along with autism. Whereas DSM-IV did not allow clinicians to assign certain diagnoses like ADHD in addition to autism, DSM-5 will permit these dual diagnoses.