Expert: Trey McGowan - 3/10/2009

Question
What is the difference between PDD-NOS and AS (Asperger's Syndrome)? Is it really necessary to differentiate the two? Is PDD-NOS milder than AS? Is PDD-NOS ever diagnosed in the teenage years?

Answer
Hi there, Kendra!

The difference between AS and PDD-NOS is that AS has specific 'identifiers' which make it what it is. I.E. there are social difficulties, the child shows focused interest in things, tends not to have severe speech deficiencies or compromised intelligence, et cetera. Asperger's Syndrome has a set of clearly defined symptoms and a number of 'looser' ones.

A PDD-NOS child, on the other hand, is very definitely showing signs of autistic issues, in particular the social difficulties and stims being the big ones, and yet is 'missing' those markers of Asperger's. Maybe they don't focus as intensely, maybe they are visibly handicapped, maybe they have severe language difficulties and yet no problems with the actual learning and education. Whatever the major difference, the removal of that major identifier means that they can no longer be filed as 'Asperger's' (or other identified ASD), though they are very definitely developmentally disabled (thus PDD; Pervasive Developmental Disorder).

PDD-NOS is generally a milder form of ASD, when compared to full autism, but this does not make it milder than Asperger's. It *can* be, but the characterization of it is that it is different, rather than milder. I like to compare it to a child having a specific allergy, and another who is simply lumped under 'hay fever'; they definitely have allergies, and the allergies can be symptomatically treated, but there is no specific tag that can be given to what single thing they are allergic to without specific testing. And in the case of ASD, there is not yet a 'specific testing' for specific types of ASD.

As for whether it can be diagnosed in the teen years, PDD-NOS can be diagnosed at any time, the same way that the other ASDs can be. It is a matter of when the symptoms are recognized and when the child, teen, or adult are actually given the full diagnosis. People are being diagnosed earlier nowadays, due to the publicity, but there are still others who did not come forward until their teen-age years.

Hopefully that answered all the questions that you had to ask! If you have others, or need more explanation on one or more of the answers I gave, don't hesitate to write back! Also, feedback and other follow-ups are certainly welcome. :)

Trey