ICD-11 or DSM-5 for ASD?

ICD-11 will officially come into effect on 1 January 2022 and supersede ICD-10.

Should Britain adopt ICD-11 as the primary reference for psychiatric and mental health conditions (including ASD) or should Britain stick with DSM-5? Please explain why.

The US previously used DSM-IV for ASD, so the changeover to DSM-5 was the changeover to a newer edition of the same manual. Britain previously used ICD-10 for ASD, so the changeover to DSM-5 was the changeover to a completely different manual.

The Americans don't generally use ICD for psychiatric and mental health conditions, so the impact of ICD-11 on ASD in the US is expected to be minimal. They will stick with DSM-5 until either DSM-6 is released or DSM is abolished.

There are significant differences between ICD-11 and DSM-5 for ASD. In ICD 11, the types of ASD are categorised whereas in DSM-5 they are a one-dimensional spectrum.

In ICD-11 we have the following categories of ASD:

6A02.0 Autism spectrum disorder without disorder of intellectual development and with mild or no impairment of functional language

6A02.1 Autism spectrum disorder with disorder of intellectual development and with mild or no impairment of functional language

6A02.2 Autism spectrum disorder without disorder of intellectual development and with impaired functional language

6A02.3 Autism spectrum disorder with disorder of intellectual development and with impaired functional language

6A02.4 Autism spectrum disorder without disorder of intellectual development and with absence of functional language

6A02.5 Autism spectrum disorder with disorder of intellectual development and with absence of functional language

6A02.Y Other specified autism spectrum disorder

6A02.Z Autism spectrum disorder, unspecified

For 6A02.0, 6A02.2, 6A02.4 intellectual functioning and adaptive behaviour are found to be at least within the average range - approximately greater than the 2.3rd percentile.

Asperger Syndrome still technically exists in ICD-11 as 6A02.0.