Autism

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.