Pervasive developmental disorder

Pervasive developmental disorders (PDD) are a group of neuropsychiatric disorder diagnoses. There are five disorders in the group.^[1]

The most common of these disorders are Autism, Asperger Syndrome, and Pervasive disorder not otherwise specified (PDD-NOS). These three disorders are also called autism spectrum disorders.

The other two disorders, Rett syndrome and Childhood disintegrative disorder (CDD), are uncommon.

A child's parents might begin to notice signs of PDD when the child is a baby. Symptoms usually appear before the child is three years old.^[2]

References

↑ "Screening for autism and pervasive developmental disorders in very young children". British Columbia Medical Journal. June 2001. Retrieved 2026-08-19.
↑ Baird G; Douglas H.R.; Murphy M S. (BMJ 2011 343). Recognising and diagnosing autism in children and young people: summary of NICE guidance. BMJ 343:

v t e Pervasive developmental disorders and autism spectrum
Main	Causes Comorbid conditions Epidemiology Heritability Societal and cultural aspects Medical model Therapies
Diagnoses	Autism spectrum High-functioning autism Low-functioning autism Classic autism Asperger syndrome Pervasive developmental disorder not otherwise specified Childhood disintegrative disorder Savant syndrome
Related conditions	Alexithymia Attention deficit hyperactivity disorder Anxiety disorder obsessive–compulsive disorder Late talker Epilepsy Fragile X syndrome Hyperlexia Rett syndrome Sensory processing disorder Intellectual disability Developmental coordination disorder Multiple complex developmental disorder
Related issues	Autism rights movement Neurodiversity Autism and LGBT identities
Controversies	Facilitated communication Lancet MMR autism fraud MMR vaccine Rapid prompting method Thiomersal Chelation
Diagnostic scales	Gilliam Asperger's disorder scale Autism Diagnostic Observation Schedule Autism Diagnostic Interview Autism-spectrum quotient Childhood Autism Rating Scale
Lists	Autism-related topics Fictional characters Schools