1. Autistic Disorder
   1. Social interaction difficulties
      1. Difficulty establishing relationships
         1. Problems in social responding
         2. Problems with joint attention
      2. Early on dislike physical affection
   2. Communication difficulties
      1. Deviations in language development
         1. echolaia-repetition of others' words/phrases
         2. palilalia-repetition of one's own words
         3. echopraxia-repetition of others' gestures/movements
         4. neologisms-made-up words
      2. Deficits in communication intent
         1. speech problems lead to conversational difficulties
         2. frequently don't use nonverbal communication
         3. comprehend things very literally
   3. Restrictive or repetitive behaviors
      1. Savant syndrome
      2. repetitive and stereotypical behavior
      3. extreme need for routine
      4. unusual preoccupation with objects or activities
      5. specific sensory or motor characteristics
   4. Cognitive characteristics
      1. Low IQ (may be off because of nature of testing)
      2. Difficulty in executive functioning
      3. Deficits in theory of mind (other peoples' perspectives)
      4. Strengths in visual skills
2. Asperger's Syndrome
   1. Social interaction difficulties
   2. Restrictive, repetitive beliefs, interests, and activities that impair other functioning areas
3. Rett's Disorder
   1. Decelerated head growth
   2. Rapid developmental regression
   3. Hypotonia (loss of muscle tone)
   4. Reduced eye contact
   5. Disinterest in play
4. Childhood Disintegrative Disorder
   1. Expressive or receptive language difficulties
   2. Social skills impairment
   3. Bowel or bladder control issues
   4. Play or motor skills loss
   5. Communication deficits
5. Pervasive Developmental Disorder-Not Otherwise Specified