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Autism

Contents of this page:

Alternative Names   

Pervasive developmental disorder - autism

Definition    Return to top

Autism is a developmental disorder that appears in the first 3 years of life, and affects the brain's normal development of social and communication skills.

Causes    Return to top

Autism is a physical condition linked to abnormal biology and chemistry in the brain. The exact causes of these abnormalities remain unknown, but this is a very active area of research. There are probably a combination of factors that lead to autism.

Genetic factors seem to be important. For example, identical twins are much more likely than fraternal twins or siblings to both have autism. Similarly, language abnormalities are more common in relatives of autistic children. Chromosomal abnormalities and other nervous system (neurological) problems are also more common in families with autism.

A number of other possible causes have been suspected, but not proven. They involve:

The exact number of children with autism is not known. A report released by the U.S. Centers for Disease Control and Prevention (CDC) suggests that autism and related disorders are more common than previously thought. It is unclear whether this is due to an increasing rate of the illness or an increased ability to diagnose the illness.

Autism affects boys 3 - 4 times more often than girls. Family income, education, and lifestyle do not seem to affect the risk of autism.

Some parents have heard that the MMR vaccine children receive may cause autism. This theory was based, in part, on two facts. First, the incidence of autism has increased steadily since around the same time the MMR vaccine was introduced. Second, children with the regressive form of autism (a type of autism that develops after a period of normal development) tend to start to show symptoms around the time the MMR vaccine is given. This is likely a coincidence due to the age of children at the time they receive this vaccine.

Several major studies have found NO connection between the vaccine and autism. The American Academy of Pediatrics and the Center for Disease Control and Prevention report that there is no proven link between autism and the MMR vaccine, or any other vaccine.

Some doctors believe the increased incidence in autism is due to newer definitions of autism. The term "autism" now includes a wider spectrum of children. For example, a child who is diagnosed with high-functioning autism today may have been thought to simply be odd or strange 30 years ago.

Other pervasive developmental disorders include:

Symptoms    Return to top

Most parents of autistic children suspect that something is wrong by the time the child is 18 months old and seek help by the time the child is age 2. Children with autism typically have difficulties in:

Some children with autism appear normal before age 1 or 2 and then suddenly "regress" and lose language or social skills they had previously gained. This is called the regressive type of autism.

People with autism may:

The symptoms may vary from moderate to severe.

Communication problems may include:

Social interaction:

Response to sensory information:

Play:

Behaviors:

Exams and Tests    Return to top

All children should have routine developmental exams done by their pediatrician. Further testing may be needed if the doctor or parents are concerned. This is particularly true if a child fails to meet any of the following language milestones:

These children might receive a hearing evaluation, blood lead test, and screening test for autism (such as the Checklist for Autism in Toddlers [CHAT] or the Autism Screening Questionnaire).

A health care provider experienced in diagnosing and treating autism is usually needed to make the actual diagnosis. Because there is no biological test for autism, the diagnosis will often be based on very specific criteria from a book called the Diagnostic and Statistical Manual IV.

An evaluation of autism will often include a complete physical and nervous system (neurologic) examination. It may also include a specific screening tool, such as:

Children with known or suspected autism will often have genetic testing (looking for chromosome abnormalities) and may have metabolic testing.

Autism includes a broad spectrum of symptoms. Therefore, a single, brief evaluation cannot predict a child's true abilities. Ideally, a team of different specialists will evaluate the child. They might evaluate:

Sometimes people are reluctant to have a child diagnosed because of concerns about labeling the child. However, without a diagnosis the child may not get the necessary treatment and services.

Treatment    Return to top

An early, intensive, appropriate treatment program will greatly improve the outlook for most young children with autism. Most programs will build on the interests of the child in a highly structured schedule of constructive activities. Visual aids are often helpful.

Treatment is most successful when it is geared toward the child's particular needs. An experienced specialist or team should design the program for the individual child. A variety of therapies are available, including:

Sensory integration and vision therapy are also common, but there is little research supporting their effectiveness. The best treatment plan may use a combination of techniques.

APPLIED BEHAVIORAL ANALYSIS (ABA)

This program is for younger children with an autism spectrum disorder. It can be effective in some cases. ABA uses a one-on-one teaching approach that reinforces the practice of various skills. The goal is to get the child close to normal developmental functioning.

ABA programs are usually done in a child's home under the supervision of a behavioral psychologist. These programs can be very expensive and have not been widely adopted by school systems. Parents often must seek funding and staffing from other sources, which can be hard to find in many communities.

TEACCH

Another program is called the Treatment and Education of Autistic and Related Communication Handicapped Children (TEACCH). TEACCH was developed as a statewide program in North Carolina. It uses picture schedules and other visual cues that help the child work independently and organize and structure their environments.

Though TEACCH tries to improve a child's adaptation and skills, it also accepts the problems associated with autism spectrum disorders. Unlike ABA programs, TEACCH programs do not expect children to achieve typical development with treatment.

MEDICINE

Medicines are often used to treat behavior or emotional problems that people with autism may have, including:

Currently, only risperidone is approved to treat children ages 5 - 16 for the irritability and aggression that can occur with autism. Other medicines that may also be used include SSRIs, divalproex sodium and other mood stabilizers, and possibly stimulants such as methylphenidate. There is no medicine that treats the underlying problem of autism.

DIET

Some children with autism appear to respond to a gluten-free or casein-free diet. Gluten is found in foods containing wheat, rye, and barley. Casein is found in milk, cheese, and other dairy products. Not all experts agree that dietary changes will make a difference, and not all studies of this method have shown positive results.

If you are considering these or other dietary changes, talk to both a doctor who specializes in the digestive system (gastroenterologist) and a registered dietitian. You want to be sure that the child is still receiving enough calories, nutrients, and a balanced diet.

OTHER APPROACHES

Beware that there are widely publicized treatments for autism that do not have scientific support, and reports of "miracle cures" that do not live up to expectations. If your child has autism, it may be helpful to talk with other parents of children with autism and autism specialists. Follow the progress of research in this area, which is rapidly developing.

At one time, there was enormous excitement about using secretin infusions. Now, after many studies have been conducted in many laboratories, it's possible that secretin is not effective after all. However, research continues.

Support Groups    Return to top

For organizations that can provide additional information and help on autism, see autism resources.

Outlook (Prognosis)    Return to top

Autism remains a challenging condition for children and their families, but the outlook today is much better than it was a generation ago. At that time, most people with autism were placed in institutions.

Today, with the right therapy, many of the symptoms of autism can be improved, though most people will have some symptoms throughout their lives. Most people with autism are able to live with their families or in the community.

The outlook depends on the severity of the autism and the level of therapy the person receives.

Possible Complications    Return to top

Autism can be associated with other disorders that affect the brain, such as:

Some people with autism will develop seizures.

The stresses of dealing with autism can lead to social and emotional complications for family and caregivers, as well as the person with autism.

When to Contact a Medical Professional    Return to top

Parents usually suspect that there is a developmental problem long before a diagnosis is made. Call your health care provider with any concerns about autism or if you think that your child is not developing normally.

References    Return to top

Autism and Developmental Disabilities Monitoring Network Surveillance Year 2002 Principal Investigators; Centers for Disease Control and Prevention. Prevalence of autism spectrum disorders--autism and developmental disabilities monitoring network, 14 sites, United States, 2002. MMWR Surveill Summ. 2007 Feb 9;56(1):12-28.

Johnson CP, Myers SM; American Academy of Pediatrics Council on Children with Disabilities. Identification and evaluation of children with autism spectrum disorders. Pediatrics. 2007;120:1183-1215.

Dover CJ, Le Couteur A. How to diagnose autism. Arch Dis Child. 2007;92:540-545.

Shah PE, Dalton R, Boris NW. Pervasive developmental disorders and childhood psychosis. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 29.

Bertoglio K, Hendren RL. New developments in autism. Psychiatr Clin North Am. 2009;32:1-14.

Update Date: 5/12/2009

Updated by: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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