What is Pervasive Developmental Disorder?

Pervasive Developmental Disorder (also known as PDD) is a general term or diagnosis used to describe individuals who have developmental delays or disorders.

Disorders on the PDD Spectrum:

The current edition of the Diagnostic and Statistical Manual (TR-IV) identifies five disorders on the PDD spectrum, including:

Autism - characterized by difficulty developing appropriate engagement in social situations or expectations. People with autism have differences in the development of their thinking, language, behavior and social skills. The differences appear before age three, and can be diagnosed by eighteen months of age. Eye contact and physical contact are avoided and they are indifferent to others. They resist interactions, do not engage with other people and often have difficulty interpreting non-verbal gestures or idiomatic phrases.

Asperger's Syndrome - People with Asperger syndrome have normal intelligence and language development, but also have some autistic-like traits. They may have trouble with social skills, sensory input, and making transitions, and may need rigid routines. Their interests can focus on one area to the point of obsession. Expert opinions are mixed on whether Asperger's syndrome should be classed as a high-functioning autism, or as a non-verbal learning disability.

Pervasive Developmental Disorder - Not Otherwise Specified (PDD-NOS) - describes autism-like behaviors and interactions that do not meet specific criteria for other Pervasive Developmental Disorders. This disorder is indicative of "severe and pervasive impairment in the development of reciprocal social interaction associated with impairment in either verbal interest and activities, but does not meet the criteria for a specific Pervasive Developmental Disorder, such as autism, asperger's, or various personality disorders."according to the Diagnostical and Statistical Manual (TR-IV).

This diagnosis is used in several medical areas, but is largely categorized into three main groups, according to the group Autism Speaks.

  • High-functioning individuals interact in a manner similar to those with Asperger's Syndrome, but are separate from those who have Aspberger's Syndrome in that high-functioning individuals have no language or cognitive delay.
  • Late-onset group consists of those who again resemble autism, but had an age of onset later than required for a diagnosis of autism.
  • Autistic-like are those who display the classic signs and symptoms of autism, but engage in fewer stereotyped and repetitive behaviors.

Rett Syndrome - is a neurological Pervasive Developmental Disorder in which there are repetitive movements such as mouthing or wringing of the hands, as well as the total inability to socialize. Girls with Rett Syndrome are prone to gastrointestinal issues and seizures. Those with Rett Syndrome often lack verbal skills.

Childhood Disintegrative Disorder - is a rare disorder with a later onset. It often is characterized by delays in language, social functions, and motor skills. Often there is a regression in skills or language, after a typical development.

What Medical Conditions May Be Found With Pervasive Developmental Disorders?

In addition to the symptoms of PDDs, several medical conditions are comorbid - or frequently found - in individuals with Pervasive Developmental Disorders.

  • Seizure disorders such as epilepsy occurs in approximately 39% of those diagnosed with Autism. According to Autism Speaks, it is more common in those with cognitive deficits. The seizures often start in early childhood, but can occur at any point. Treatment typically includes anti-convulsant medication.
  • Genetic disorders are common complications in which there is a family history of genetic disorders, or there are physical symptoms present. Often these are not treatable.
  • Gastrointestinal disorders are common in children diagnosed with PDD, including chronic constipation or diarrhea.
  • Sleep disorders occur commonly in children with autism, caused by medical issues such as sleep apnea or acid reflux.
  • Pica is a disorder in which individuals eat objects that are not food. This is persistent beyond a developmentally appropriate age.


First Signs, Inc. provides the following signs indicating a child with Pervasive Developmental Disorder:

  • No big smiles or other warm, joyful expressions by six months or thereafter
  • No back-and-forth sharing of sounds, smiles, or other facial expressions by nine months or thereafter

  • No babbling by twelve months old

  • No back-and-forth gestures, such as pointing, showing, reaching, or waving by twelve months old

  • No words by sixteen months old

  • No two-word meaningful phrases (without imitating or repeating) by twenty-four months old

  • Any loss of speech or babbling or social skills at any age

If you see these warning signs, please contact a health professional as soon as possible for further assessment and diagnosis.

Diagnosis of Pervasive Developmental Disorders is crucial to treatment. The earlier a child is diagnosed, the sooner treatment can begin and the better a chance your child has of recovering skills and abilities. Often therapy for the entire family, special classes, and programs are utilized to treat Pervasive Developmental Disorders.

Related Resource Pages on Band Back Together:


 Asperger's Syndrome

Developmental Milestones

How To Help A Parent of A Special Needs Child

Special Needs Parenting

Additional Resources for Pervasive Developmental Disorder:

Autism, Asperger's Syndrome, PDD-NOS - fact sheet about the various types of Pervasive Developmental disorders, including autism, Asperger's syndrome and PDD-NOS.

Oasis @ MAAP – contains a wealth of information about autism, autistic spectrum disorders and Asperger's Syndrome along with a local and national help center locator.

Autism Society – information, news articles and links to resources for family members, health care professionals and those diagnosed with autism, ASD and Asperger's Syndrome.

Asperger’s Documentary – short video that explains what it’s like to live with Asperger Syndrome.

Talk About Curing Autism Cards – business cards that can be passed out to people staring at your autistic child. On the front the cards say,

"My Child’s Behavior May Be Disturbing To You.
My Child Is Not Spoiled or Misbehaving.

On the back it gives facts about autism.

The Complete Guide to Asperger’s Syndrome by Tony Attwood. A heavy read, almost like a textbook.

Look Me in the Eye: My Life with Asperger’s by John Elder Robison.  Written by a man who was not diagnosed with Asperger Syndrome until he was an adult.  It’s a great first-person account.

The OASIS Guide to Asperger Syndrome: Completely Revised and Updated: Advice, Support, Insight, and Inspiration by Patricia Romanowski Bashe and Barbara L. Kirby. This book was written by two mothers of children with Asperger's Syndrome. It compiles information they’ve gathered from studies, personal experience, and the experiences of the many, many parents who come to the website they founded — one of the first resources for parents of children with AS.

The Out-of-Sync Child: Recognizing and Coping with Sensory Processing Disorder, Revised Edition and The Out-of-Sync Child Has Fun, Revised Edition: Activities for Kids with Sensory Processing Disorder by Carol Kranowitz.