PDD-NOS

Pervasive Developmental Disorder - Not Otherwise Specified

The term "Pervasive Developmental Delay" is the label put on people who have conditions that affect speech, communication, emotional growth, socialization, and physical capabilities. PDDs include:

Asperger's syndrome
Autism / Kanner's Syndrome
Childhood Disintegrative Disorder
Fragile X Syndrome
Rett Syndrome
Angelman Syndrome*
Cornelia de Lange Syndrome*
Landau-Kleffner Syndrome*
Prader-Willi Syndrome*
Williams Syndrome*

The "Not Otherwise Specified" part means just that; the person has symptoms of one or more of these but doesn't fit into any true diagnoses.

The term PDD-NOS is used mostly by doctors who diagnose patients with it, even though it means "we have no idea what you have." Seen as a dustbin diagnosis, most patients and caregivers prefer "Autistic Spectrum Disorder".