The DSM-5 Changes
The DSM-5 Changes
Four years ago a panel of reviewers stood over the mangled body of the DSM-IV and said "We can rebuild it". They tossed some bits away, melded other bits together and stuck in a few new parts... and now here we are at the tail end of an 18 month review process, with our last chance to comment on the stronger, faster Steve Austin criteria for diagnosing autism.
So let's pop the hood and see what we've got here...
Why did things need to change?
The DSM is not just about autism, it contains guidelines for diagnosing nearly 300 different physical and mental health disorders. Our knowledge and understanding of these disorders is advancing all the time, so it's appropriate that the manual is updated to reflect these changes.
Since the first edition was published back in 1952 there have only been four versions and two revisions, the last of which was in 2000 (and that was pretty minor, retaining most of the text from the 1994 version). So the manual was long overdue for a bit of a makeover.
What has changed from DSM-IV?
There are seven major changes in the proposed DSM-5 criteria for autism:
Autistic Disorder, Aspergers and PDD-NOS have been folded into a single disorder called Autism Spectrum Disorder
The three domains of impairment (Social Interaction, Communication and Restricted/Repetitive Behaviour) have become two, with the merging of the first two
All of the criteria within this new Social Communication domain must be met
The language delay criterion has been removed
There is a new severity rating scale
The requirement that behaviours must have appeared before the age of three has been dropped
Sensory processing issues have been included as a distinct criterion
Let's look at those in more detail...
1. A single spectrum
The pool of behaviours that define the three Autism Spectrum Disorders under DSM-IV are essentially the same, and there's not a lot of evidence to support Asperger's and PDD-NOS as clinically separate disorders from Autism. And since there's no clear difference in outcomes or treatments, the APA has decided that one disorder is a better representation of our current knowledge about what autism is.
2. Merging social and communication deficits
This move was designed to reflect the reality that these kinds of deficits aren't always distinct from each other. One of the big problems with applying the DSM-IV criteria is that many of the difficulties autistic kids have in social settings are a direct result of their communication deficits. Sometimes the same behaviour would fall under communication deficits in one context but social deficits in another, such as the inability to engage someone in conversation. So it was felt that having two-thirds of the criteria based around the same kinds of deficits was unnecessary duplication, and was skewing autism diagnoses towards those people with social and communication difficulties.
Merging the domains has also made way for the inclusion of the next controversial change...
3. All of the Social Communication criteria must be met
The APA believe that requiring all criteria in this domain to be met will improve "specificity of diagnosis without impairing sensitivity" - that it will help rule out people who are not autistic without affecting the ability to find the people who are. I think what they're trying to say here is that if you're autistic you'll have no trouble meeting all of these criteria, and if you're not then you will... or something.
4. Rethinking language delay
Another key impact of the changes is to take the focus off language delay as a deciding factor in diagnosis. As the APA puts it "delays in language are not unique nor universal in ASD" - you don't have to be autistic to have a language delay, and you don't have to have a language delay to be autistic. So it really wasn't adding anything to the diagnostic process.
5. The severity rating scale
Those that are diagnosed with Autism Spectrum Disorder under the new criteria will now also receive a rating of severity. There are three severity levels:
1 - Requiring support
2 - Requiring substantial support
3 - Requiring very substantial support
There are descriptions for behaviours under each of the two domains within each severity level.
6. Lifting the age requirement
This is in recognition of the fact that for many kids, early support from parents and limited exposure to social situations may mask autistic behaviours until after the current cut-off age of three.
7. Including sensory processing issues
The inclusion of over- or under-reactions to sensory input as a separate criterion is a welcome addition that reflects a growing acceptance of the role that the sensory system plays in autistic behaviours.
I always think better when I can see stuff, so to get my head around all of these changes I made them into handy graphics - you can find them on the Snagglebox Downloads page. They look like this, but bigger...
And here are the criteria changes in table form...