Regarding developmental disorders, there are two main categories.
- Specific developmental disorder
- Pervasive developmental disorder
This disorder selectively touches one area of development, and does not span across multiple areas of development. The important thing to remember here is the disorder is in one specific category. For example, someone might have a stuttering disorder which is part of the Speech Articulation Disorder category. The stuttering disorder does not span across other categories, just the person's communication. Or someone might have a specific phobia which is part of the Mood Disorder category. These are all specific developmental disorders.
Pervasive Developmental Disorder
With the pervasive developmental disorder. the disorder spans across multiple categories. For example, autism is an example of a pervasive developmental disorder which affects various categories ( e.g. social skills, communicating, behavior, thinking, etc.) Because the disorder transcends across multiple categories, it's called pervasive. Pervasive developmental disorder is usually characterized by delays in the development of multiple primary roles (such as socialization, communication, etc.)
Here is a list of the pervasive developmental disorders:
- Pervasive developmental disorder not otherwise specified (PDD-NOS), which includes atypical autism
- Asperger syndrome
- Rett syndrome
- Childhood disintegrative disorder
Hope that helps...