Autism
Neurodevelopmental Disorders & Learning Differences
Key Takeaways
- PDD-NOS (Pervasive Developmental Disorder – Not Otherwise Specified) was a diagnosis used before 2013 to describe individuals who had some, but not all, features of autism.
- Since the release of the DSM-5 in 2013, PDD-NOS is no longer an official diagnosis and has been replaced by the umbrella term Autism Spectrum Disorder (ASD).
- PDD-NOS was considered a milder or atypical form of autism, often given when a child had clearly autistic-like delays or behaviors that did not meet the full criteria for classic autism or Asperger’s Syndrome.
- 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.
- Families with a pre-2013 PDD-NOS diagnosis can consult a developmental specialist to update it to ASD so that educational plans, therapies, and services align with current criteria.
Authored by: The DrSensory Editorial Team
Reviewed by: 🛡️ DrSensory Clinical Review Board
Last updated: June 2026
Frequently Asked Questions
What is PDD-NOS?
PDD-NOS, or Pervasive Developmental Disorder – Not Otherwise Specified, was a diagnosis used before 2013 for individuals who showed some but not all features of autism. People with PDD-NOS typically had delays in social interaction, communication, and behavior, but their symptoms did not meet the full criteria for classic autism or Asperger’s Syndrome.
How is PDD-NOS different from autism or Asperger’s syndrome?
PDD-NOS was considered a milder or atypical form of autism. Unlike classic autism, individuals might not have language delays or repetitive behaviors, and unlike Asperger’s Syndrome, they may have had more noticeable issues with communication or motor skills.
Is PDD-NOS still diagnosed today?
No, PDD-NOS is no longer used as a clinical diagnosis. In 2013, the DSM-5 replaced it with Autism Spectrum Disorder (ASD) to better reflect the wide range of characteristics and severities within autism.
What does a PDD-NOS diagnosis become under today’s criteria?
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 my child was previously diagnosed with PDD-NOS?
If your child received a PDD-NOS diagnosis before 2013, it is helpful to consult with a developmental specialist to update the diagnosis to Autism Spectrum Disorder (ASD) under the current criteria. This helps ensure that educational plans, therapies, and services match today’s standards.
