Autism is a disorder that affects the brain’s development of social and communication skills. It is actually a group of disorders, called autism spectrum disorders. It is estimated that six out of every 1,000 children in the United States may have an autism spectrum disorder, with approximately four times as many boys affected as girls.

Some autism spectrum disorders have more severe symptoms than others. For example, classical autism involves more severe social and communication dysfunction than milder forms, such as:

  • Asperger’s syndrome: A child has autistic behaviors but well-developed language skills.
  • Pervasive developmental disorder not otherwise specified (PDD-NOS): A child has some autistic symptoms but not enough to be diagnosed with classical autism.
  • Childhood disintegrative disorder: Social and communications skills develop normally but suddenly deteriorate between three and 10 years old and marked autistic behaviors appear.
  • Rhett syndrome: Social and communications skills develop normally for 6-18 months before regression and autistic behaviors begin to appear.

Autism Symptoms

The signs of autism vary greatly but are primarily related to social interaction and communication. Some of the most common signs include:


  • Problems with verbal communication, such as delayed speech development or speech that develops normally but then suddenly regresses
  • Problems with non-verbal communication, such as eye contact, smiling, and pointing (infants and toddlers)
  • Problems with holding a conversation


  • Problems expressing emotions or understanding how others think and feel
  • Inability to understand social cues, such as tone of voice or facial expressions, or to watch people’s faces for clues about appropriate behavior
  • Inability to play interactively with other children

Routines or repetitive behaviors

  • Excessively repeating words or actions
  • Obsessively following routines or schedules
  • Playing in excessively repetitive ways