Autism Spectrum Disorders and Low Mental Age: Diagnostic Stability and Developmental Outcomes in Early Childhood

J Autism Dev Disord. 2017 Dec;47(12):3967-3982. doi: 10.1007/s10803-017-3278-y.

Abstract

Some children with autism spectrum disorders (ASDs) exhibit low mental age (Low-MA; i.e., cognitive functioning below 12 months). We examined diagnosis, symptom severity, and development in children with ASD-low MA (n = 25), autistic disorder (n = 111), and PDD-NOS (n = 82) at ages two and four. We predicted that some ASD-low MA children would demonstrate just intellectual impairment and not autism symptoms on follow-up, with social deficits at age two attributable to global delays. Instead, most ASD-low MA children (96%) had an ASD at follow-up, compared to children initially diagnosed with autistic disorder (86.5%) or PDD-NOS (73.2%). They showed the least developmental progress and highest symptom severity. Results support diagnosing ASDs in children functioning below a 12-month level.

Keywords: Autism severity; Autism spectrum disorders; Developmental growth; Diagnostic stability; Low mental age.

Publication types

  • Evaluation Study

MeSH terms

  • Autism Spectrum Disorder / diagnosis*
  • Autism Spectrum Disorder / psychology
  • Child Development
  • Child Development Disorders, Pervasive / diagnosis*
  • Child Development Disorders, Pervasive / psychology
  • Child, Preschool
  • Cognition
  • Early Diagnosis
  • Female
  • Follow-Up Studies
  • Humans
  • Intellectual Disability / diagnosis*
  • Intellectual Disability / psychology
  • Intelligence
  • Male
  • Social Behavior Disorders / diagnosis*
  • Social Behavior Disorders / psychology
  • Symptom Assessment / methods
  • Symptom Assessment / psychology*