What are Pervasive Developmental Disorders?

///What are Pervasive Developmental Disorders?
What are Pervasive Developmental Disorders? 2017-10-20T21:43:21+00:00

What are Pervasive Developmental Disorders / PDD / PDD-NOS?

The diagnostic category of pervasive developmental disorders (PDD) refers to a group of disorders characterized by delays in the development of socialization and communication skills. Parents may note symptoms as early as infancy, although the typical age of onset is before 3 years of age.

Symptoms may include:

  • Problems with using and understanding language
  • Difficulty relating to people, objects, and events
  • Unusual play with toys and other objects (i.e. lining up cars, spinning wheels, sorting blocks by size or color)
  • Difficulty with changes in routine or familiar surroundings
  • Repetitive body movements or behavior patterns.

Autism (a developmental brain disorder characterized by impaired social interaction and communication skills, and a limited range of activities and interests) is the most characteristic and best studied PDD. Other types of PDD include Asperger’s Syndrome, Childhood Disintegrative Disorder, and Rett’s Syndrome.

Children with PDD vary widely in abilities, intelligence, and behaviors. Some children do not speak at all, others speak in limited phrases or conversations, and some have relatively normal language development. Repetitive play skills and limited social skills are generally evident. Unusual responses to sensory information, such as loud noises and lights, are also common.

Sometimes individuals that don’t neatly fit into one classification but who are considered on the autism spectrum are diagnosed with PDD-NOS or Pervasive Developmental Disorder, Not Otherwise Specified.

Please note that information on this page references the way that Pervasive Developmental Disorders are classified in the 4th version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). This reference guide from the American Psychiatric Association is the primary diagnostic reference guide used by clinicians from the period of 1994 until May 2013 (and in some cases, beyond). In May 2013, a new version was published, the DSM-5. This version has reclassified PDD under the umbrella term “Autism Spectrum Disorder”.

What is PDD – NOS?

Pervasive Developmental Disorder – Not Otherwise Specified (PDD-NOS) is one of the five disorders classified as a Pervasive Developmental Disorder (PDD). Other Pervasive Developmental Disorders include Autism, Asperger’s Disorder, Rett’s Disorder and Childhood Disintegrative Disorder. Oftentimes, PDD-NOS is referred to as “atypical PDD,” or “atypical autism”.

What are Signs, Symptoms and Characteristics of PDD – NOS?

As with all individuals on the autism spectrum, it is important to keep in mind that no two individuals with PDD – NOS are exactly alike. Commonly, individuals with PDD – NOS have more intact social skills and have less intellectual deficits than individuals with other PDD’s. Many individuals with PDD – NOS have characteristics in common, such as:

  • Communication difficulties (e.g., using and understanding language)
  • Difficulty with social behavior
  • Difficulty with changes in routines or environments
  • Uneven skill development (strengths in some areas and delays in others)
  • Unusual play with toys and other objects
  • Repetitive body movements or behavior patterns
  • Unusual likes and dislikes

How is PDD – NOS Diagnosed?

Using the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), a diagnosis of PDD – NOS is provided when full features for autism or another diagnostic category defined in PDD are not met. An individual may have difficulties in the area of social interaction, communication, and/or stereotyped behavior patterns or interests; however, specific guidelines for a diagnosis of PDD – NOS are not provided. It does not mean that PDD – NOS is less of a disability than the other PDD’s. 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, behavior and socialization.

It is important to have a full diagnostic evaluation when considering a PDD – NOS diagnosis. As with any Pervasive Developmental Disorder, a comprehensive evaluation including a thorough medical, social, adaptive, motor skills and communication history are imperative. A pediatric neurologist, developmental pediatrician, or a psychologist are a few professionals who may diagnose PDD – NOS. When seeking a diagnosis, it is important to include a team of specialists when considering a Pervasive Developmental Disorder to be present.

What kind of Treatment or Intervention is available?

While there is no known “cure” for Pervasive Development Disorder – Not Otherwise Specified there are strategies that have a positive impact. As with other pervasive development disorders such as Autism and Asperger’s Disorder, it is believed that early, intensive use of evidenced based practices and interventions customized to the individual can significantly improve the outcomes of individuals with PDD-NOS.

Most of these interventions fall under the category of special education as opposed to medical services such as prescriptions. In the educational setting, specialized instruction and individualized educational plans should be developed to meet the individual’s specific needs and will contribute to success. Some of the more common therapies and services include:
  • Visual and Environmental Supports, visual schedules (Hodgdon, 2002)
  • Applied Behavior Analysis
  • Discrete Trial Instruction
  • Social Stories and Comic Strip Conversations (Gray, 2000)
  • Speech and Language Services
  • Physical and Occupational Therapy

The best outcomes can be achieved when a team approach amongst supporting individuals is utilized. Remember that no two individuals on the autism spectrum are the same and treatment that may work with one individual may have a different result with another.


Health-related material is provided for information purposes only and does not represent endorsement by or an official position of Autism Empowerment. Advice on the treatment or care of an individual patient should be obtained through consultation with a physician who has examined that patient or is familiar with that patient’s medical history.