A diagnosis of autism is made based on the behaviours that doctors or psychologists can see and those that parents tell them about. There isn’t a blood test or other way of knowing that someone has autism. Clinicians need to carefully look at the child’s communication and social skills and find out about their interests and repetitive behaviours. The signs and symptoms that the clinician sees can then be compared with a list of characteristics of autism, such as those in a book call the Diagnostic and Statistical Manual (DSM). This book is written by experts working with the American Psychiatric Association and includes descriptions of a number of different conditions, including autism, anxiety and language impairment. The most recent version of the book is the fifth edition and so it is known as DSM-5.
The DSM-5 was published in May 2013. There were a number of changes to the way some of the conditions are described. There were many important changes to the way autism is described and diagnosed.
The changes in brief
- In DSM-IV, there were three separate names for autism spectrum disorder (Autistic Disorder, Asperger syndrome and PDD-NOS). Now there is just one: autism spectrum disorder (ASD).
- In DSM-IV, there were three main areas of difficulties (social, communication and interests/behaviour). Now there are only two. These are Social Communication and Restricted and Repetitive Patterns of Behaviour Interests and Activities.
- The person’s history is now more important – symptoms of autism can now be counted if they are seen now or if the person used to have them (e.g. lining up toys or rocking when younger).
- There are now severity ratings ranging from Level 1 - Requiring Support to Level 3 – Requiring Very Substantial Support.
- Sensory behaviours, such as being sensitive to sound or seeking out movement, are recognised under the Restricted and Repetitive Patterns of Behaviour Interests and Activities (RIRB) domain.
Why did it change?
Research showed that doctors and psychologists were good at figuring out which children have ASD and which children were developing typically. However, they weren’t as reliable in sorting children into the three categories (i.e. autistic disorder, Asperger syndrome and PDD-NOS). It was also hard to see any difference between older people with a diagnosis of high functioning autism and people with Asperger syndrome.
Because autism is defined by a common set of behaviours, experts feel that it is best described by one label (autism spectrum disorder) with other information about severity, intellectual ability and other features (such as epilepsy) also included.
What are the issues?
There was a lot of discussion and disagreement about the changes to DSM before they were made. The first concern was that the diagnosis of Asperger syndrome (AS) wouldn’t be used anymore. For people already diagnosed with AS, there was a concern that there would be a loss of identity. People were also worried that some people with good language and thinking skills would no longer be on the spectrum and that they would lose services.
A new category of “Social Communication Disorder” was included for people who have social and communication difficulties similar to those seen in ASD but who don’t have the same restricted interests and repetitive behaviours.
What about current diagnoses?
DSM-5 states that “Individuals with a well-established DSM-IV diagnosis of autistic disorder, Asperger’s disorder or pervasive developmental disorder not otherwise specified should be given the diagnosis of autism spectrum disorder.” This means that people diagnosed with any of the three autism spectrum disorders described under DSM-IV criteria should receive a diagnosis under DSM-5. No one should lose a diagnosis because of the change. There is limited information about whether fewer people are getting a new diagnosis because of DSM-5.
- The way autism is diagnosed has changed.
- There is now only one diagnosis – autism spectrum disorder.
Nothing should change for people who already had a diagnosis under the old system.
For more information, please refer to the extended version of this fact sheet.
(Reviewed in November 2016)