Autism

Autism is a highly variable neurodevelopmental disorder that first appears during infancy or childhood, and generally follows a steady course without remission. Overt symptoms gradually begin after the age of six months, become established by age two or three years, and tend to continue through adulthood, although often in more muted form.

It is distinguished not by a single symptom, but by a characteristic triad of symptoms: impairments in social interaction; impairments in communication; and restricted interests and repetitive behavior. Other aspects, such as atypical eating, are also common but are not essential for diagnosis. Autism's individual symptoms occur in the general population and appear not to associate highly, without a sharp line separating pathologically severe from common traits.

Autistic individuals display many forms of repetitive or restricted behavior, which the Repetitive Behavior Scale-Revised (RBS-R) categorizes as follows:

   
Symptoms
 
  • Steryotypy is repetitive movement, such as hand flapping, making sounds, head rolling, or body rocking.

  • Compulsive Behavior is intended and appears to follow rules, such as arranging objects in stacks or lines.

  • Ritualistic Behavior involves an unvarying pattern of daily activities, such as an unchanging menu or a dressing ritual.

  • Restricted Behavior is limited in focus, interest, or activity, such as preoccupation with a single television program, toy, or game.