A pervasive developmental disorder not otherwise specified is one of the three
autism spectrum disorders and also one of the five disorders classified as a
pervasive developmental disorder. According to the DSM-IV, PDD-NOS is a
diagnosis that is used for "severe and pervasive impairment in the development
of reciprocal social interaction or verbal and nonverbal communication
skills, or when stereotyped behavior, interests, and activities are present,
but the criteria are not met for a specific PDD" or for several other
disorders. PDD-NOS is often called atypical autism, because the criteria
for autistic disorder are not met, for instance because of late age of onset,
atypical symptomatology, or subthreshold symptomatology, or all of these. Even
though PDD-NOS is considered milder than typical autism, this is not always true.
While some characteristics may be milder, others may be more severe.
Signs and symptoms It is common for individuals with
PDD-NOS to have more intact social skills and a lower level of intellectual
deficit than individuals with other PDDs. Characteristics of many
individuals with PDD-NOS are: Communication difficulties
Difficulty with social behavior Difficulty with changes in routines or
environments Uneven skill development
Unusual play with toys and other objects Repetitive body movements or behavior
patterns Diagnosis
PDD-NOS is an old diagnostic category. It is no longer included as an option
for an Autism Spectrum Disorder and is not part of the DSM-5, but is included
in the ICD-10. The diagnosis of a pervasive
developmental disorder not otherwise specified is given to individuals with
difficulties in the areas of social interaction, communication, and/or
stereotyped behavior patterns or interests, but who do not meet the full
DSM-IV criteria for autism or another PDD. This does not necessarily mean that
PDD-NOS is a milder disability than the other PDDs. It only means that
individuals who receive this diagnosis do not meet the diagnostic criteria of
the other PDDs, but that there is still a pervasive developmental disorder that
affects the individual in the areas of communication, socialization and
behavior. As for the other pervasive developmental
disorders, diagnosis of PDD-NOS requires the involvement of a team of
specialists. The individual needs to undergo a full diagnostic evaluation,
including a thorough medical, social, adaptive, motor skills and communication
history. Other parts of an assessment can be behavioral rating scales, direct
behavioral observations, psychological assessment, educational assessment,
communication assessment, and occupational assessment.
Description of PDD-NOS merely as a "subthreshold" category without a more
specific case definition poses methodological problems for research
regarding the relatively heterogeneous group of people who receive this
diagnosis. However, it appears that children with PDD-NOS show fewer
intellectual deficits than autistic children, and that they may come to
professional attention at a later age. = Subgroups =
Studies suggest that persons with PDD-NOS belong to one of three very
different subgroups: A high-functioning group whose symptoms
largely overlap with that of Asperger syndrome, but who differ in terms of
having a lag in language development and/or mild cognitive impairment.
A group whose symptoms more closely resemble those of autistic disorder, but
do not fully meet all its diagnostic signs and symptoms.
The biggest group consists of those who meet all the diagnostic criteria for
autistic disorder, but whose stereotypical and repetitive behaviors
are noticeably mild. Treatment
There is no known "cure" for PDD-NOS, but there are interventions that can
have a positive influence. Early and intensive implementation of
evidence-based practices and interventions are generally believed to
improve outcomes. Most of these are individualized special education
strategies rather than medical or pharmaceutical treatment; the best
outcomes are achieved when a team approach among supporting individuals is
utilized. Some of the more common therapies and
services include: Visual and environmental supports,
visual schedules Applied behavior analysis
Discrete trial instruction Social stories and comic strip
conversations Physical and occupational therapy
References