What is PDD-NOS?

This Article Written By Lisa Jo Rudy

Autism Spectrum Disorders Expert 

My child has been diagnosed with something called PDD-NOS. What is PDD-NOS? Is it the same thing as autism?

Answer: PDD-NOS is an outdated diagnostic category which stands for pervasive developmental disorder not otherwise specified.  In essence, it's a diagnosis that means "on the autism spectrum, but not falling within any of the existing specific categories of autism."
To explain more fully: up until May 2013, there were five disorders that fell under the category of "pervasive developmental disorders" (PDDs).

• Autism
• High Functioning Autism
• Children with Autism
• Autistic
• Autism Spectrum Disorder

These included Autism, Asperger syndrome, Rett syndrome, Fragile X syndrome, and PDD-NOS. Autism, Asperger syndrome, Rett syndrome and fragile X were all specifically described in the DSM-IV -- the manual that practitioners used to diagnose neurological 

                                     disorders. 

Once the DSM-5 was published, however, the term PDD-NOS "disappeared" from the diagnostic literature.  Most people who once had the PDD-NOS diagnosis would now be considered to have an "autism spectrum" diagnosis instead.
Here is the explanation of PDD-NOS which describes what the diagnosis WAS, before it was removed from the DSM in 2013:                                                                                                                                                     Many children have some symptoms of one PDD and some symptoms of another, but not enough of any one of the four specific disorders to receive a diagnosis. Thus, they do have a PDD -- but they do not have Rett syndrome, fragile X, Asperger syndrome, or autism.