Autism

Autism is one of the mental, emotional, and behavior disorders that appears in early

childhood.  Autism, or autistic disorder, almost always develops within the first 3 years of a

child's life.  Children and adolescents with autism cannot interact normally with other people.

Autism thus affects many aspects of their development.

Children with and adolescents with autism typically:

-have a difficult time communicating with others

-exhibit very repetitious behaviors (like rocking back and forth, head banging, or touching or

twirling objects);

-have a limited range of interests and activities; and

-may became  upset at a small change in their environment or daily routine.

Although symptoms of autistic disorder sometimes can be seen in early infancy, the

condition can appear after months of normal development.  In most cases, it is not possible to

identify any specific event that triggers autistic disorder.  About 7 in every 10 children and

adolescents with autistic disorder also have mental retardation or other problems with their brain

function or structure. 

Recent studies estimate that as many as 14 children out of 10,000 may have autism or a

related condition.  About 125,000 Americans are affected by these disorders, and nearly 4,000

families across the country have two or more children with autism.  Three times as many boys as

girls have autism.

Researchers are still unsure about what causes autism.  Several studies suggest that

autistic disorder might be caused by a combination of biological factors, including exposure to a

virus before birth, a problem with the immune system, or genetics.

Scientists also have identified chemicals in the brain and the immune system that may be

involved in autistic disorder.  As a normal brain develops, the level of serotonin, a chemical found

in the brain, declines.  In some children with autistic disorder, however, the serotonin levels do

not decline.  Now researchers are trying to determine whether this happens only to children with

autism and why, and whether other factors are involved.