The unspoken assumption is that by the age of five, unusual behaviors will either resolve or develop into diagnosable autism. However, some parents view the PDD label as no more than a euphemism for autism spectrum disorders, problematic because this label makes it more difficult to receive aid for early childhood intervention. Classification
The pervasive developmental disorders were:
Pervasive developmental disorder not otherwise specified (PDD-NOS), which includes atypical autism, and is the most common (47% of autism diagnoses);
Typical autism, the best-known;
Asperger syndrome (9% of autism diagnoses);
Rett syndrome; and
Childhood disintegrative disorder (CDD).The first three of these disorders are commonly called the autism spectrum disorders; the last two disorders are much rarer, and are sometimes placed in the autism spectrum and sometimes not.In May 2013, the Diagnostic and Statistical Manual–5th Edition (DSM-V) was released, updating the classification for pervasive developmental disorders. The grouping of disorders, including PDD-NOS, Autism, Asperger Syndrome, Rett Syndrome, and CDD, has been removed and replaced with the general term of Autism Spectrum Disorders. The American Psychiatric Association has concluded that using the general diagnosis of ASD supports more accurate diagnoses. The combination of these disorders was also fueled by the standpoint that Autism is characterized by common symptoms and should therefore bear a single diagnostic term. In order to distinguish between the different disorders, the DSM-V employs severity levels. The severity levels take into account required support, restricted interests and repetitive behaviors, and deficits in social communication. PDD and PDD-NOS
There is a division among doctors on the use of the term PDD.
Treatment
Medications are used to address certain behavioral problems; therapy for children with PDD should be specialized according to the childs specific needs.Some children with PDD benefit from specialized classrooms in which the class size is small and instruction is given on a one-to-one basis. Others function well in standard special education classes or regular classes with support. Early intervention, including appropriate and specialized educational programs and support services, play a critical role in improving the outcome of individuals with PDD. See also
Infantile neuroaxonal dystrophy
Multiple complex developmental disorder
Multisystem developmental disorder
Overactive disorder associated with mental retardation and stereotyped movements

References
External links
CDCs "Learn the Signs. Act Early." campaign - Information for parents on early childhood development and developmental disabilities
NINFS Pervasive Developmental Disorders Information Page