This post is a more in-depth analysis of the issue identified in an earlier post, in regards to the potential exclusion of those with intellectual disability from an autism diagnosis. This is a complex issue and I am open to alternate views and understandings; I openly encourage you to share such in the comments.
The wording of the proposed fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5, due May 2013) category for Autism Spectrum Disorder (ASD), appears to begin with an exclusion of those with general developmental delays. It states that the “persistent deficits in social communication and social interaction” required for a diagnosis of ASD under criteria A, must be “not accounted for by general developmental delays.”
“General developmental delays” here appears to potentially encompass a range of disorders, including the new categories “Intellectual or Global Developmental Delay Not Elsewhere Classified” (IGDD) and Intellectual Developmental Disorder.” (IDD). IGDD is used where symptoms are perhaps not yet clear enough to qualify for a more specific diagnosis, such as the child is as yet too young to be properly assessed. IDD generally replaces the old category of Mental Retardation, but specifically moves away from requiring a specific IQ score (of about 70).
The concern is that the wording under the new criteria A for an ASD diagnosis, goes beyond the stated interests of those who have chosen (and are working on) the wording. From various sources (such as here and here), it is clear that there is not an express desire to exclude those with general developmental delays (largely including the intellectually disabled as a group), so much as a desire to clarify when ASD is comorbid with, and when it is different from, such conditions. There is clear appreciation of the fact that it can be and often is comorbid with intellectual disabilities (for example).
However, the actual language in the proposed criteria, and the way in which is is then likely to be put into practice, seems to act as an exclusion rather than a differentiation or clarification. If the social communication and social interaction deficits are accounted for by general developmental delay, it looks like that – in and of itself – will exclude an ASD diagnosis. This would be regardless of the person meeting criteria B, C and D, since each and every criteria must itself be met; falling short of criteria A would exclude the ASD diagnosis.
If the aim was to make sure a general developmental delay is not mistaken for ASD (and that does seem to be the guiding concern of the framers), then I would think there were two better options: (1) That there be included in the ASD category an explicit reminder to diagnosticians to consider whether the observed delays are perhaps better explained by some other condition (with listed examples of those alternatives), or (2) that the criteria be written in such a way that their very operation will serve to clarify when someone has ASD, so that there is no need to say anything about general developmental delays. I am sure these alternatives occurred to the writers, what is unclear thus far is why they decided slipping it into criteria A with that chosen wording, was their best option.
If it is just poor wording – regardless of the best intentions behind it – it would not be the first time there has been a significant slip-up in the wording for an ASD diagnosis under the DSM. The DSM-IV, published in 1994, had an error under PDD-NOS (the largest autism grouping). Across the three areas of communication, behaviour and social interaction, someone with PDD-NOS was meant to have impairments in more than one area, but the final text used the wrong wording leading to a requirement of only needing one of the three criteria for a diagnosis of PDD-NOS. The error was corrected in the 2000 revised edition of the DSM-IV, but by then “psychiatrists, psychologists, and epidemiologists throughout the world had been following these extremely broad criteria for six years, during the period when the so-called ‘[autism] epidemic’ emerged.” (Quote from “Unstrange Minds” by Roy Richard Grinker.) So it is not inconceivable that another oversight with serious consequences, could occur, and take a while to fix. That is, if the chosen wording under the DSM-5 is an oversight at all.
I can see how one might view it more as an deliberate effort to remove the intellectually disabled from ASD altogether. My personal view on this though is that it’s poorly chosen wording (particularly because it makes more sense to ascribe people honest and open intentions accompanied by poor wording arrangement, rather than assign a conspiracy theory model to their actions. Benefit of the doubt.) Though I am just a lay-person, I am not alone in my concerns about how the chosen wording might be implemented, and am equally not convinced by the replies to those concerns. It is perfectly possible that I (and others) have misunderstood the wording and potential application, but there is clearly room there for that confusion to blossom, and I would hope that the final version addresses such concerns.