1.
INTRODUCTION
The
term Pervasive Developmental Disorders was first used in
the 1980s to describe a class of disorders. This class of
disorders has in common the following characteristics: impairments
in social interaction, imaginative activity, verbal and
nonverbal communication skills, and a limited number of
interests and activities that tend to be repetitive.
The
manual used by physicians and mental health professionals
as a guide to diagnosing disorders is the Diagnostic and
Statistical Manual of Mental Disorders (DSM). The DSM was
last revised in 1994. In this latest revision, known as
the DSM-IV, five disorders are identified under the category
of Pervasive Developmental Disorders: (1) Autistic Disorder,
(2) Rett's Disorder, (3) Childhood Disintegrative Disorder,
(4) Asperger's Disorder, and (5) Pervasive Developmental
Disorder Not Otherwise Specified, or PDDNOS.
Many
of the questions parents and education professionals ask
NICHCY have to do with children who have been diagnosed
with "PDD." Doctors are divided on the use of
the term PDD. Many professionals use the term PDD as a short
way of saying PDDNOS. Some doctors, however, are hesitant
to diagnose very young children with a specific type of
PDD, such as Autistic Disorder, and therefore only use the
general category label of PDD. This approach contributes
to the confusion about the term, because the term PDD actually
refers to a category of disorders and is not a diagnostic
label. The appropriate diagnostic label to be used is PDDNOS--Pervasive
Developmental Disorder Not Otherwise Specified--not PDD
(the umbrella category under which PDDNOS is found).
