Mental Disorders in America (cont.)


  • Autism affects an estimated 1 to 2 per 1,000 people.
  • Autism and related disorders (also called autism spectrum disorders or pervasive developmental disorders) develop in childhood and generally are apparent by age 3.
  • Autism is about 4 times more common in boys than girls. Girls with the disorder, however, tend to have more severe symptoms and greater cognitive impairment.

Alzheimer's Disease

  • Alzheimer's disease, the most common cause of dementia among people age 65 and older, affects an estimated 4 million Americans.
  • As more and more Americans live longer, the number affected by Alzheimer's disease will continue to grow unless a cure or effective prevention is discovered.
  • The duration of illness, from onset of symptoms to death, averages 8 to 10 years.

For more information about these conditions, please visit the following areas:
Portions of the above information has been provided with the kind permission of the National Institute of Mental Health, National Institutes of Health (
Last Editorial Review: 7/7/2004