Autism in Children and Adolescents

If you’re concerned about autism specifically in he context of children and adolescents, this document from the National Mental Health Information Center provides an overview and offers additional information about getting help.

What is autism?

Autism, also called autistic disorder, appears in early childhood, usually before age 3 (National Institutes of Health, 2001). Autism prevents children and adolescents from interacting normally with other people and affects almost every aspect of their social and psychological development.

What are the signs of autism?

Autism has a wide variety of characteristics ranging in intensity from mild to severe. One child with autism does not behave like another child with the same diagnosis. Children and adolescents with autism typically:

  • Have difficulty communicating with others.
  • Exhibit repetitious behaviors, such as rocking back and forth, head banging, or touching or twirling objects.
  • Have a limited range of interests and activities.
  • May become upset by a small change in their environment or daily routine.

In addition to these characteristics, some children with autism experience hypersensitivity to hearing, touch, smell, or taste. Symptoms of autism can be seen in early infancy, but the condition also may appear after months of normal development. In most cases, however, it is not possible to identify a specific event that triggers the disorder.

How common is autism?

Studies estimate that as many as 12 in every 10,000 children have autism or a related condition (U.S. Department of Health and Human Services, 1999). Autism is three times more common in boys than in girls (National Institutes of Health, 2001).

What causes autism?

Researchers are unsure about what causes autism. Several studies suggest that autism might be caused by a combination of biological or environmental factors, or both, including viral exposure before birth, a problem with the immune system, or genetics. Many recently published scientific investigations have examined the possible connection between autism and the measles, mumps, and rubella (MMR) vaccine. At this time, though, the available data do not appear to support a causal link.

Studies of families and twins suggest a genetic basis for the disorder. It is important for scientists to find the genes responsible for autism, if any, because this knowledge would give physicians new tools to diagnose the disorder and help scientists develop gene-based therapies.

Some studies have found that the brains of people with autism may function differently from those that are considered “normal.” Research suggests that an abnormal slowing down of brain development before birth may cause autism. Studies also are looking at how autism-related problems in brain development may affect behavior later in childhood. For example, some researchers are investigating the ways in which infants with autism process information and how the disorder may lead to poor development of social skills, knowledge, and awareness.

Chemicals in the brain also may play a role in autism. As a normal brain develops, the level of serotonin, a chemical found in the brain, declines. In some children with autism, however, serotonin levels do not decline. Researchers are investigating whether this happens only to children with autism or whether other factors are involved.

What help is available for families?

Since brain development can be influenced during early childhood, the treatment of autism has a greater chance of success when initiated as early as possible. In addition, when children with autism are treated early, the cost of long-term care may be reduced. Services and treatments that may benefit children and adolescents with autism and their families include:

  • Training in communication, social, learning, and self-help skills.
  • Programs in which other children help to teach children with autism.
  • Parent training.
  • Medications to reduce symptoms related to self-injury, seizures, digestive difficulties, and attention problems.

When services are started soon after a child is diagnosed with autism, the child's language, social, and academic skills and abilities may be greatly improved. On the other hand, some children and adolescents do not respond well to treatment or may experience negative side effects from autism medications. Recent data suggest that some of the newer antipsychotic drugs may have fewer side effects than conventional drugs, but more studies are needed before experts can determine any possible safety advantages over traditional treatments.

What can parents do?

Parents or other caregivers concerned about a child who shows symptoms of autism should:

  • Talk with a health care provider about their concerns. He or she can help to determine whether the symptoms are caused by autism, a related disorder, or another condition. If necessary, the health care provider can refer the family to a mental health expert who specializes in treating persons with autism.
  • Get accurate information from libraries, hotlines, or other sources.
  • Ask questions about treatments and services.
  • Talk to other families in their communities who are coping with autism.
  • Find family network organizations.

People who are not satisfied with the mental health care they receive should discuss their concerns with the provider, ask for information, and/or seek help from other sources.


National Institutes of Health. (2001). Fact Sheet: Unraveling Autism. Bethesda, MD: National Institutes of Health.

U.S. Department of Health and Human Services. (1999). Mental Health: A Report of the Surgeon General. Rockville, MD: U.S. Department of Health and Human Services.

This document appears courtesy of the US government’s National Mental Health Information Center.

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