U.S. Department of Health & Human Services
Improving the health, safety, and well-being of America	Frequent Questions Search

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In the absence of a cure, interventions designed to alleviate specific symptoms are available. The best studied therapies include educational, behavioral and pharmacological interventions. Children who receive these therapies show progress in social and language skills.

UNDERSTANDING AUTISM

Autism and Autism Spectrum Disorder (ASD)
No one child with autism behaves like another child with the same diagnosis. Each case is unique because autism is a spectrum disorder, meaning that it is defined by a wide variety of characteristics ranging from mild to severe. This spectrum has grown out of increased education and research about the disorder, which at one time operated under a limited definition. With increased awareness and knowledge, more children are beginning to receive the support and services they need to function with a life-long, pervasive disorder.

Autism impacts normal brain development, leaving most individuals with communication problems, difficulty with normal social interactions, and prone to repeat specific patterns of behavior. There are five diagnoses under the spectrum disorders (technically referred to as the Pervasive Development Disorders):

• Autistic Disorder is characterized in some children by withdrawn behavior or other unusual social behaviors, problems using language to communicat, repetitive patterns of behavior and the inability to engage in imaginative play.

• Children diagnosed with Asperger's Syndrome usually display the same general symptoms, but have well developed language skills and normal or near-normal IQ.

• Pervasive Developmental Disorder - Not Otherwise Specified (PDD-NOS, or atypical autism) occurs when a child may not fall within the realm of other ASDs, but nonetheless shows signs of a severe developmental disorder with significant autistic symptoms.

• Rett's Syndrome has only appeared in girls to date. These children seem to develop normally until between 6 and 18 months, then lose language and motor abilities. Recently, a genetic marker for Rett's Syndrome has been identified.

• Childhood Disintegrative Disorder refers to the normal development of children until two years of age, who then rapidly lose acquired skills. This usually occurs between 36 and 48 months of age, but may occur up to 10 years of age.

Current Treatments for Autism
There are two main types of treatment for autism: behavioral and pharmacological. Behavioral treatments usually include intensive, one-on-one speech and communication therapy. Behavioral intervention can be used to teach skills in many areas including communication, social, learning, and self-help areas. Children with autism who receive this type of intervention often show an increased capacity for social, emotional and behavioral understanding. Pharmacological treatments center around specific autistic symptoms, such as self-injurious actions, unusual activity level and attention problems, digestive difficulties and seizures.

RESEARCH AND SURVEILLANCE ON AUTISM

Vaccines and Autism
Recently there has been attention focused on the theory that autistic behaviors in children seemed to occur or to worsen shortly after vaccination. At the current time, no conclusive data indicate that any vaccine increases the risk of developing autism or any other behavior disorder. Nonetheless, given the level of concern among parents and others regarding vaccines and autism, the CDC is committed to investigating this issue to the fullest extent possible using the best scientific methods available.

The largest and most comprehensive studies conducted on this subject to date conclude that there is no link between the vaccines and autism. In 1990, a study published by the Institute of Medicine concluded that there was no evidence to indicate a relationship between autism and the diphtheria/tetanus/pertussis (DTP) vaccine, or the pertussis component of the DTP vaccine. In 1999, a British study by Taylor and colleagues of nearly 500 known autism cases in a region of London concluded that there is no link between autism and the measles/mumps/rubella (MMR) vaccine.

In the fall of 2000, the National Academy of Sciences' Institute of Medicine (IOM) convened the Immunization Safety Review Committee, charged with examining three vaccine-safety hypotheses each year through 2003. In 2001, the committee was asked to assess the scientific plausibility of the MMR vaccine contributing to the onset of ASD by examining scientific studies and any pathogenic mechanisms. In April 2001, the committee concluded that there is no basis for implicating the MMR vaccine as a potential cause of autistic spectrum disorders (ASD). Recognizing that scientific studies can never be absolute in their conclusions, the IOM recommended further research to explore the possibility that exposure to MMR vaccine could be a risk factor for ASD in rare cases. The Committee concluded that there is no need to review the existing recommendations for routine use of MMR at 12-15 months of age and 4-6 years of age. The Committee's conclusion supports the current policy of giving the MMR vaccine as a combination vaccine instead of administering each of the components (measles, mumps, and rubella) separately.

In June 2000, the American Academy of Pediatrics (AAP) held a multidisciplinary, international workshop to review evidence regarding a possible association between MMR vaccine and ASD and inflammatory bowel disease. Based on this conference, the AAP Executive Committee has concluded that no data exists to suggest a causal relationship between MMR and autism or inflammatory bowel disease. The Committee also stated that a reluctance to have children vaccinated with MMR would result in a serious public health threat. A full report of the workshop will be published in the journal Pediatrics in May 2001.

Vaccine Safety
Under the National Childhood Vaccine Injury Act of 1986, the Vaccine Adverse Event Reporting System (VAERS) was developed to collect, manage and examine possible adverse events linked to vaccines. This national database helps scientists and researchers identify a pattern of unusual reactions from a specific vaccine. Another system of monitoring possible adverse events is the CDC's Vaccine Safety Datalink (VSD), an electronic network of health maintenance organizations used to analyze information from reports of possible adverse events following administration of vaccines. This year, CDC reallocated $4 million in federal funds to amplify vaccine safety activities such as VAERS and other special projects. The fiscal year 2001 budget calls for a total of $13.4 million to improve vaccine safety by expanding the VSD network, continuing VAERS follow-up reports and special studies, as well as specific education and communication program.

HHS Research and Surveillance on Autism
HHS agencies are working to determine prevalence rates of children with autism and other developmental disabilities, as well as broaden the research agenda on autism.

National Institutes of Health (NIH): In 1997, NIH established the NIH Autism Coordinating Committee (NIH/ACC) as part of an effort to enhance and expand its research program in autism. The NIH/ACC provides a forum for identifying opportunities for collaboration and coordination among the institutes and centers concerned with autism research and related activities. Members include the National Institute of Neurological Disorders and Stroke (NINDS), the National Institute of Child Health and Human Development (NICHD), the National Institute of Mental Health (NIMH) and the National Institute on Deafness and Other Communication Disorders (NIDCD). The NIH/ACC also includes advisory representatives from the National Institute of Environmental Health Sciences, National Institute of Allergy and Infectious Diseases, and the National Center for Complementary and Alternative Medicine.

A major focus of current interest for NIH/ACC is the identification of biological markers or medical tests that can determine the presence or absence of autism. In the fall of 2000, scientists under NIH's Collaborative Program of Excellence in Autism, the single largest autism research project supporting 10 multidisciplinary programs, identified a gene that may predispose people to developing autism. The gene, known as HOXA1 seems to play a fundamental role in early brain development. Researchers tested 57 people diagnosed with autism for a variant of the HOXA1 gene. Results indicated that 40 percent of those tested, or 22 people, carried a mutated version of HOXA1.

Scientists have also discovered a major gene for Rett's syndrome, one of the five autism spectrum disorders, and developed the first full human genome scan in autism, which identifies potential genetic "hotspots" for the disorder. In addition, NINDS, NIMH and NICHD are sponsoring a study of normal structural and metabolic brain development in infants to provide control data for research of developmental disorders. The NIH is also supporting several clinical trials to test the effectiveness of the hormone secretin as a treatment for autism.

In November 2001, NICHD developed six fact sheets describing the latest research findings on autism. The series, available on the NICHD Web site, provides a general overview of autism, questions and answers for health care professionals, a summary of genetic research, research efforts on autism and vaccines, background on Rett Syndrome and program information for the NICHD/NIDCD Collaborative Programs of Excellence in Autism. To view the fact sheets, go to www.nichd.nih.gov/autism/.

Centers for Disease Control and Prevention (CDC): In April of 2001, a National Center on Birth Defects and Developmental Disabilities was established at the CDC to improve the health of children and adults by preventing birth defects and developmental disabilities, promiting optimal child development, as well as ensuring health and wellness among children and adults living with disabilities. The CDC is currently one of the few agencies in the world operating a population-based surveillance system on autism. In 1991, the CDC started the Metropolitan Atlanta Developmental Disabilities Surveillance Program to monitor the prevalence of developmental disabilities -- mental retardation, cerebral palsy, vision and hearing impairments -- in children ages 3 to 10. Autism disorders were added to the surveillance program in 1998.

A recent investigation by the CDC in Brick Township, N.J., found autism prevalence rates among 3 to 10-year-olds to be 4 per 1,000 children, and a rate of 6.7 per 1,000 children for the more broadly defined category of autism spectrum disorders. It is not known how many children in the United States currently have autism or a related disorder. The interpretation of results from the Brick Township prevalence investigation will not be fully understood until additional prevalence rates have been obtained from other geographically and socio-economically diverse communities.

The CDC also provides funding for Marshall University Autism Training Center in West Virginia, to develop and implement a program to prevent secondary conditions among children with autism and their families. The university is also studying ways to monitor the prevalence of autism in six counties of West Virginia.

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Note: All HHS press releases, fact sheets and other press materials are available at http://www.hhs.gov/news.