Pervasive Developmental Disorder - Not Otherwise Specified
(PDD-NOS)
SOURCE: AUTISMSPEAKS.ORG
What is PDD-NOS?
PDD-NOS stands for Pervasive Developmental Disorder-Not Otherwise Specified. PDD-NOS was one of several previously separate subtypes of autism that were folded into the single diagnosis of autism spectrum disorder (ASD) with the publication of the DSM-5 diagnostic manual in 2013.
In the past, psychologists and psychiatrists often used the term “pervasive developmental disorders” and “autism spectrum disorders” (ASD) interchangeably. As such, PDD-NOS became the diagnosis applied to children or adults who are on the autism spectrum but do not fully meet the criteria for another ASD such as autistic disorder (sometimes called “classic” autism) or Asperger syndrome.
Like all forms of autism, PDD-NOS can occur in conjunction with a wide spectrum of intellectual ability. Its defining features are significant challenges in social and language development.
Some developmental health professionals refer to PDD-NOS as “subthreshold autism." In other words, it’s the diagnosis they use for someone who has some but not all characteristics of autism or who has relatively mild symptoms. For instance, a person may have significant autism symptoms in one core area such as social deficits, but mild or no symptoms in another core area such as restricted, repetitive behaviors.
As a diagnosis, PDD-NOS remains relatively new, dating back only 15 years or so. As a result, some physicians and educators may not be familiar with the term or may use it incorrectly.
The current Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) spells out the criteria for a diagnosis of PDD-NOS. Unfortunately, this description consists of a single paragraph, which mainly asserts what it is not:
"This category should be used when there is severe and pervasive impairment in the development of reciprocal social interaction associated with impairment in either verbal or nonverbal communication skills or with the presence of stereotyped behavior, interests, and activities, but the criteria are not met for a specific Pervasive Developmental Disorder, Schizophrenia, Schizotypal Personality Disorder, or Avoidant Personality Disorder. For example, this category includes “atypical autism” – presentations that do not meet the criteria for Autistic Disorder because of late age at onset, atypical symptomatology, or subthreshold symptomatology, or all of these."
More helpful, perhaps, are studies suggesting that persons with PDD-NOS can be placed in one of three very different subgroups:
- A high-functioning group (around 25 percent) whose symptoms largely overlap with that of Asperger syndrome, but who differ in terms of having a lag in language development and mild cognitive impairment. (Asperger syndrome does not generally involve speech delay or cognitive impairment).
- A second group (around 25 percent) whose symptoms more closely resemble those of autistic disorder, but do not fully meet all its diagnostic signs and symptoms.
- A third group (around 50 percent) who meet all the diagnostic criteria for autistic disorder, but whose stereotypical and repetitive behaviors are noticeably mild.
As these findings suggest, individuals with PDD-NOS vary widely in their strengths and challenges.
How might a parent or an affected adult recognize PDD-NOS?
PDD-NOS is characterized by delays in the development of socialization and communication skills. Parents may notice associated behaviors as early as infancy. These may include delays in using and understanding language, difficulty relating to people, unusual play with toys and other objects, difficulty with changes in routine or surroundings and repetitive body movements or behavior patterns.
How should Pervasive Developmental Disorder (PDD-NOS) be treated?
As with all autism spectrum disorders, early diagnosis and intervention offer the best chance for optimizing outcomes – including success in mainstream classrooms and the achievement of independence and a high quality of life in adulthood. However, it is never too late to begin behavioral therapy.
As previously mentioned, no two individuals with PDD-NOS are alike. Indeed, they can have completely different strengths and challenges. As a result, treatments and interventions should be highly individualized based on a thorough assessment by a qualified developmental specialist. The evaluation should consider such factors as behavioral history, current symptoms, communication patterns, social competence and neuropsychological functioning.
Parents of children diagnosed with PDD-NOS should pursue an Early Intervention Program (EIP) for a young child and an Individual Education Program (IEP) for a school-age child. For more information, see the Autism Speaks 100 Day Kit and IEP Guide.
Learn the Signs of Autism
One of the most important things you can do as a parent or caregiver is to learn the early signs of autism and become familiar with the typical developmental milestones that your child should be reaching.
What are the signs of autism?
The autism diagnosis age and intensity of autism’s early signs vary widely. Some infants show hints in their first months. In others, behaviors become obvious as late as age 2 or 3.
Not all children with autism show all the signs. Many children who don’t have autism show a few. That’s why professional evaluation is crucial.
The following may indicate your child is at risk for an autism spectrum disorder. If your child exhibits any of the following, ask your pediatrician or family doctor for an evaluation right away:
By 6 months
- Few or no big smiles or other warm, joyful and engaging expressions
- Limited or no eye contact
By 9 months
- Little or no back-and-forth sharing of sounds, smiles or other facial expressions
By 12 months
- Little or no babbling
- Little or no back-and-forth gestures such as pointing, showing, reaching or waving
- Little or no response to name
By 16 months
- Very few or no words
By 24 months
- Very few or no meaningful, two-word phrases (not including imitating or repeating)
At any age
- Loss of previously acquired speech, babbling or social skills
- Avoidance of eye contact
- Persistent preference for solitude
- Difficulty understanding other people’s feelings
- Delayed language development
- Persistent repetition of words or phrases (echolalia)
- Resistance to minor changes in routine or surroundings
- Restricted interests
- Repetitive behaviors (flapping, rocking, spinning, etc.)
- Unusual and intense reactions to sounds, smells, tastes, textures, lights and/or colors
If you have concerns, get your child screened and contact your healthcare provider
The M-CHAT (Modified Checklist for Autism in Toddlers ™) can help you determine if a professional should evaluate your child. This simple online autism screen, available on our website, takes only a few minutes. If the answers suggest your child has a high probability for autism, please consult with your child’s doctor. Likewise, if you have any other concerns about your child's development, don't wait. Speak to your doctor now about screening your child for autism.
Resources
A diagnosis of autism is an important turning point in a long journey to understand your child's world. Autism Speaks has many resources for families whose children have recently received a diagnosis.
These include Autism Speaks First Concern to Action Tool Kit and First Concern to Action Roadmap.
Signs of autism in adults and teens
Do you suspect that your feelings and behaviors involve autism? Many people who have milder forms of autism go undiagnosed until adulthood. Find out more in our guide: "Is it Autism and If So, What Next?"
Please visit Treatment of Autism and our Autism Speaks Directory for more information. Have more questions? Autism Speaks' Autism Response Team can help you with information, resources and opportunities. Call us at 888-288-4762 (en Español 888-772-9050) or email help@autismspeaks.org.