Autism

Neurodevelopmental Disorders & Learning Differences

What Is PDD-NOS? Understanding Pervasive Developmental Disorder–Not Otherwise Specified and Its Place on the Autism Spectrum

Authored by: The DrSensory Editorial Team

Reviewed by: 🛡️ DrSensory Clinical Review Board

Last updated: June 2025

All medical content on this page has been reviewed and approved by licensed Doctors on the DrSensory Clinical Review Board. Our reviewers follow strict editorial standards and ensure alignment with current APTA guidelines, evidence-based practice, and orthopedic rehabilitation protocols.

What is Pervasive Developmental Disorder – Not Otherwise Specified (PDD-NOS)?

PDD-NOS, or Pervasive Developmental Disorder – Not Otherwise Specified, was a diagnosis used before 2013 to describe individuals who had some—but not all—features of autism. People with PDD-NOS typically showed delays in social interaction, communication, and behavior, but their symptoms didn’t meet the full criteria for classic autism or Asperger’s Syndrome.

Since the release of the DSM-5, PDD-NOS is no longer an official diagnosis and has been replaced by the umbrella term Autism Spectrum Disorder (ASD).

How was PDD-NOS different from autism or Asperger’s syndrome?

PDD-NOS was considered a “milder” or atypical form of autism. Unlike classic autism, individuals with PDD-NOS might not have language delays or exhibit repetitive behaviors. And unlike Asperger’s Syndrome, they may have more noticeable issues with communication or motor skills.

The diagnosis was often given when a child had developmental delays or behaviors that were clearly autistic-like, but didn’t meet all the criteria for other defined disorders on the spectrum.

Is PDD-NOS still diagnosed today?

No, PDD-NOS is no longer used as a clinical diagnosis. In 2013, the DSM-5 replaced PDD-NOS with Autism Spectrum Disorder (ASD) to better reflect the wide range of characteristics and severities within autism.

People who were previously diagnosed with PDD-NOS are now typically classified under Level 1 or Level 2 ASD, depending on the level of support they need.

What should I do if I or my child was previously diagnosed with PDD-NOS?

If you or your child received a PDD-NOS diagnosis before 2013, it’s helpful to consult with a developmental specialist to update the diagnosis to Autism Spectrum Disorder (ASD) under the current criteria. This ensures that educational plans, therapies, and services are aligned with today’s standards.

Understanding where you fall on the autism spectrum can also improve access to appropriate support, such as speech therapy, occupational therapy, or individualized learning accommodations.

This page provides general educational content and is not a substitute for professional medical advice. Always consult a licensed provider for diagnosis and treatment.

Therapist Ratings & Reviews

Find a Therapist near you

Are you looking for a physical, occupational, or speech therapist in your area?
Look no further than the DrSensory Therapist Database and Clinic Directory!

What Are Others Reading?

Got Concerns?

Find a Therapist

Find the physical therapist, occupational therapist, or speech language pathologist you’re looking for!

Ask Us Anything

Whether you are looking for advice, have a general question about sensory processing, or looking for resources.

Submit Your Story

Share your story about your child. Let’s celebrate milestones and learn more about challenges.