The diagnostic category pervasive developmental disorders (PDD), as opposed to specific developmental disorders (SDD), is a group of disorders characterized by delays in the development of multiple basic functions including socialization and communication. The pervasive developmental disorders include autism, Asperger syndrome, pervasive developmental disorder not otherwise specified (PDD-NOS, i.e., all autism spectrum disorders [ASD]), childhood disintegrative disorder (CDD), overactive disorder associated with mental retardation and stereotyped movements, and Rett syndrome. The first four of these disorders are commonly called the autism spectrum disorders; the last disorder is much rarer, and is sometimes placed in the autism spectrum and sometimes not.The terminology PDD and ASD is often used interchangeably and varies depending on location. The two have overlapping definitions but are defined differently by the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-V), and the International Classification of Diseases, 10th edition (ICD-10). DSM-V removed PDD as a diagnosis and replaced it with ASD and the relative severity of the condition. ICD-10 on the other hand labels ASD as a pervasive developmental disorder with the subtypes previously mentioned.The onset of pervasive developmental disorders occurs during infancy, but the condition is usually not identified until the child is around three years old. Parents may begin to question the health of their child when developmental milestones are not met, including age appropriate motor movement and speech production.There is a division among doctors on the use of the term PDD. Many use the term PDD as a short way of saying PDD-NOS (pervasive developmental disorder not otherwise specified).
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.