Early Indicators of Autism Spectrum Disorder

A young boy playing with a puzzle.

Photo by Pragyan Bezbaruah

Screening & Diagnosis


The earliest symptoms of ASD can emerge between 6 – 18 months of age, with reliable diagnosis possible by 24 months. These symptoms are developmental “red flags” and do not necessarily mean your child has ASD but you may want to contact your child’s doctor if you notice these symptoms in your child.

  • Lack of warm, joyful expressions or big smiles
  • No back-and-forth sharing of sounds, smiles or other facial expressions
  • Any loss of speech, babbling or social skills

  • No babbling
  • No back-and-forth gestures, such as waving or pointing
  • No response to his or her name but may respond to other sounds
  • Lack of eye contact and interest in faces
  • Dislike of being touched or cuddled
  • Any loss of speech, babbling or social skills

  • No spoken words
  • Speech may be limited to imitating what is heard
  • No meaningful, two-word phrases
  • No shared enjoyment in activities
  • Any loss of speech, babbling or social skills
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This information was developed by the Autism Services, Education, Resources, and Training Collaborative (ASERT). For more information, please contact ASERT at 877-231-4244 or info@PAautism.org. ASERT is funded by the Bureau of Supports for Autism and Special Populations, PA Department of Human Services.