Autism Spectrum Disorders

General characteristics • Usually diagnosed during age 2
• Male:female ratio-4:1
• 80% have IQs below 70
Clinical signs • Usually evident by age 3 years
• Problems with reciprocal social interaction
• Abnormal/delayed language development, impaired verbal and nonverbal communication
• No separation anxiety
• Oblivious to external world
• Fails to assume anticipatory posture, shrinks from touch
• Preference for inanimate objects
• Stereotyped behavior; decreased repertoire of activities and interests
Potential causes • Association with prenatal and perinatal injury, e.g., rubella in first trimester
• Possible role of environmental mercury exposure
• Proposed mechanism: failure of apoptosis in cortex
Treatment • Behavioral techniques (shaping)


Autistic disorder

  • Early infantile or childhood autism
  • 4 times more common in boys than in girls
  • Moderate to severe range of communication, socialization, and behavior problems
  • Most also have intellectual disability

Rett syndrome

  • Primarily females
  • Development is normal in the first 6-18 months
  • Regression or loss of abilities
  • Meaningless gestures or movements

Childhood disintegrative disorder

  • Regression in multiple areas of function following a period of at least 2 years of normal development
  • Onset by age 10 years

Asperger’s Syndrome

  • Later onset than autistic disorder
  • Characteristics
    • Lack of social skills (poor eye contact, anxiety)
    • Difficulty understanding subtleties used in conversation
    • Difficulty with social relationships
    • Poor coordination
    • Poor concentration
    • Restricted range of interests
  • Average to above average intelligence/language skills
    •  Incorrectly referred to as high-functioning autism