The Difference Between Aspergers and PDD-NOS

Question

My 7-year-old son has been diagnosed with ADHD. The pediatrician also thinks that he may have Aspergers or Pervasive developmental disorder not otherwise specified. After researching the two diagnoses, I see that they are very similar. What type of testing can I have done to determine what kind of help my son needs?

Answer

Like Autism and Aspergers, Pervasive developmental disorder not otherwise specified (PDD-NOS) is one of the five subtypes of the Autism Spectrum Disorders. Children diagnosed with PDD-NOS will have less social impairment than a youngster with Autism or Aspergers.

The Autism Spectrum Disorders are:

1. Pervasive developmental disorder not otherwise specified
2. Autism
3. Asperger syndrome
4. Rett syndrome
5. Childhood disintegrative disorder

To confuse matters, there is a division among therapists on the use of the term Pervasive Developmental Disorder (PDD), which is the same thing as Autism Spectrum Disorder (ASD). Many use the term PDD as a short way of saying PDD-NOS. Others use the general category label of PDD because they are hesitant to diagnose very young kids with a specific type of PDD (e.g., Autism). Both approaches contribute to confusion about the term, because the term PDD actually refers to a category of disorders and is not a diagnostic label.

PDD is not itself a diagnosis, while PDD-NOS is. To further complicate the issue, PDD-NOS can also be referred to as “atypical personality development,” “atypical PDD,” or “atypical Autism.”

Some clinicians use PDD-NOS as a "temporary" diagnosis for youngsters under the age of 5, when for whatever reason there is a reluctance to diagnose Autism. There are several justifications for this. Very young kids have limited social interaction and communication skills to begin with, thus it can be tricky to diagnose milder cases of Autism in a toddler. The unspoken assumption is that by the age of 5, unusual behaviors will either resolve or develop into diagnosable Autism.

Because of the "NOS" (i.e., not otherwise specified), it is hard to describe what PDD-NOS is, other than its being an Autism Spectrum Disorder (ASD). Some children diagnosed with PDD-NOS are close to having Aspergers, but do not quite fit the profile. Others have near full-blown Autism, but without some of its symptoms. The field of psychology is considering creating several subclasses within PDD-NOS.

To confirm the diagnosis, continue to consult with your doctor and get a referral to either a neurologist or child and adolescent psychiatrist to figure out exactly what is going on with your child. Once you have a definitive answer, you can then check for resources in your local area. Each U.S. state has different resources tied-in with the local schools. Your doctor should be able to point you in the right direction. If not, the local school district should have some referrals for you.

The Aspergers Comprehensive Handbook