Autism, Asperger, Pervasive Developmental Disorder

Clinical Reference Groups Mental Health CRG
1

Summary of request and discussion:

Hi All

We have received a request from Canada to inactivate the following concepts, which they consider outdated, and would appreciate your feedback on this proposal.

  • 23560001 |Asperger’s disorder (disorder)| - 1 descendant

  • 35919005 |Pervasive developmental disorder (disorder)|, the preferred term already for this concept is Autism Spectrum Disorder - 47 descendants (including Asperger’s)

Rationale provided:

  • Pervasive developmental disorder (PDD) is an umbrella term no longer used in current classifications. It does not appear in DSM-5 or ICD-11. Historically, it encompassed several conditions now classified under Autism spectrum disorder (ASD). In SNOMED CT, ASD is currently modeled as a synonym of PDD, which the requester highlights as problematic.

  • Asperger’s disorder is no longer a recognised diagnosis in DSM-5 or ICD-11, and is now subsumed under Autism spectrum disorder (ASD).

Requester’s aim:

  • To align SNOMED CT terminology with current diagnostic standards (DSM-5 and ICD-11).

  • To ensure Autism spectrum disorder is represented independently and accurately, rather than being tied to PDD.

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In my initial analysis I noted the following:

DSM-5

  • DSM-5 (2013) consolidated autistic disorder, Asperger’s disorder, childhood disintegrative

disorder, and PDD-NOS under Autism Spectrum Disorder (ASD).

  • Individuals with prior DSM-IV diagnoses of these conditions should now be diagnosed with

ASD.

  • DSM-5 abandoned terms such as Asperger syndrome and PDD as distinct entities due to poor

reliability and validity.

ICD-11

  • ICD-11 (2019) removed Asperger’s syndrome and pervasive developmental disorders as

separate entities.

  • All such conditions are consolidated under Autism Spectrum Disorder (ASD).

  • WHO aligned ICD-11 with DSM-5 to harmonize autism classification.

  • Source: Autism-Europe summary of ICD-11

Nature of Pervasive Developmental Disorder (PDD)

  • PDD was an umbrella/grouper category, not a distinct clinical diagnosis.

  • Subcategories included autistic disorder, Asperger’s disorder, childhood disintegrative disorder,

and PDD-NOS.

  • PDD-NOS was often a residual category when full criteria for autism or Asperger’s were not

met.

Further International Evidence

  • National Autistic Society — Asperger syndrome page

    • Asperger syndrome … is no longer used as a diagnostic term. … Broadly, it is now agreed that what was referred to as Asperger syndrome is part of the autism spectrum and there is no need for a separate term.

  • HSE Ireland

    • Doctors do not diagnose people with Asperger’s anymore because it’s now thought of as part of autism. If you were diagnosed with it in the past, you are now understood to have autism. You do not need to be assessed or diagnosed again.

  • Government of Canada — Autism Spectrum Disorder

    • National reporting and surveillance use Autism Spectrum Disorder (ASD) only. PDD is mentioned historically but not used as a current diagnostic category.

  • NZ Ministry of Health — DSM-5 Implications for Autism

    • DSM-5 implications paper used in national guidance confirms the retirement of PDD and Asperger’s as standalone categories, with ASD as the replacement.

Additional References

However, I note that a recent proposal has been submitted to WHO for the introduction of a new diagnostic category — Cognitive Rigidity with Social Difficulties (CRSD). The submission argues that, while Asperger’s syndrome was subsumed under Autism Spectrum Disorder (ASD) in DSM-5 and ICD-11, emerging evidence suggests that it may represent a distinct clinical entity. The proposal highlights increasing ASD diagnosis rates and seeks to recognise a subgroup with traits historically associated with Asperger’s but distinct from classic autism presentations.

This proposal has not yet been reviewed by WHO’s Medical and Scientific Advisory Committee (MSAC). Its existence suggests that the issue may not be as straightforward as first assumed, and that further debate continues within the clinical community.

Although discussions in this area may continue to evolve, the current evidence strongly suggests these concepts are outdated. I would welcome your views on whether this supports their inactivation at this time.

Many thanks

Elaine

2

For countries who are not yet on ICD-11, will there be a gap b/w documentation and coding if concepts like Asperger.s are inactivated in SNOMED CT? Is there a proposed solution for this use case? Thanks!

3

@cpapoutsakis

Thanks for posting this.

Note that the post above is a cut and paste of the content of an email summary of issues from the terminologist working on the request.

4

Hi @cpapoutsakis This post is intended to explore the wider issue, and the point you’ve highlighted is one of the areas we’re actively discussing in the Mental and Behavioural Health CRG. We’d very much welcome the community’s perspectives.

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