PDD-NOS (pervasive developmental disorder, not otherwise specified)

Pervasive developmental disorder was the umbrella heading in the older manuals, and PDD-NOS, sometimes called atypical autism Autism Autism is a difference in how the brain develops. It shapes how an autistic child sees and experiences the world, how they communicate, and how they respond to things like noise, light and touch. Read the full definition of Autism , was the category used when a child did not fit neatly into the others.

NICE guidance NICE guidelines Expert advice that tells the NHS how to assess and treat health conditions. It is used in England, Wales and Northern Ireland, but not Scotland. Read the full definition of NICE guidelines for the NHS describes that umbrella as covering autism, Asperger's syndrome Asperger's syndrome Asperger's syndrome was a diagnosis that doctors used to give. It is now part of the autism diagnosis, and a diagnosis given at the time was a real diagnosis. Read the full definition of Asperger's syndrome and atypical autism, or pervasive developmental disorder not otherwise specified. Those categories were folded into the single autism diagnosis when the manuals were updated, the same change that retired Asperger's syndrome: DSM-5 in 2013 and ICD-11 in 2019.

This is the same story as Asperger's. A diagnosis given under the old category was a real diagnosis from a real assessment. New assessments simply do not use the category any more.