Autism spectrum disorders (ASDs) are a group of developmental disabilities that are caused by an abnormality in the brain. People with ASDs tend to have problems with social and communication skills.

They also are likely to repeat certain behaviors and to not want change in their daily activities. Many people with ASDs also have unusual ways of learning, paying attention, or reacting to different sensations. ASDs begin during childhood and last throughout a person\'s life.

The following question and answer section will help you learn more about ASDs.

-- What are some of the symptoms of ASDs?

-- What conditions are included in ASDs?

-- How common are ASDs?

-- What causes ASDs? Can they be treated?

-- Where can I go to learn more about ASDs?

What are some of the symptoms of ASDs?

As the name \"autism spectrum disorder\" says, ASDs cover a wide range of behaviors and abilities.

People who have ASDs, like all people, differ greatly in the way they act and what they can do. No two people with ASDs will have the same symptoms. A symptom might be mild in one person and severe in another person.

Some examples of the types of problems and behaviors a child or adult with an ASD might have follow.

-- Social skills: People with ASDs might not interact with others the way most people do, or they might not be interested in other people at all. People with ASDs might not make eye contact and might just want to be alone. They might have trouble understanding other people\'s feelings or talking about their own feelings. Children with ASDs might not like to be held or cuddled, or might cuddle only when they want to. Some people with ASDs might not seem to notice when other people try to talk to them. Others might be very interested in people, but not know how to talk, play, or relate to them.

-- Speech, language, and communication: About 40% of children with ASDs do not talk at all. Others have echolalia, which is when they repeat back something that was said to them. The repeated words might be said right away or at a later time. For example, if you ask someone with an ASD, \"Do you want some juice?\" he or she will repeat \"Do you want some juice?\" instead of answering your question. Or a person might repeat a television ad heard sometime in the past. People with ASDs might not understand gestures such as waving goodbye. They might say \"I\" when they mean \"you\", or vice versa. Their voices might sound flat and it might seem like they cannot control how loudly or softly they talk. People with ASDs might stand too close to the people they are talking to, or might stick with one topic of conversation for too long. Some people with ASDs can speak well and know a lot of words, but have a hard time listening to what other people say. They might talk a lot about something they really like, rather than have a back-and-forth conversation with someone.

-- Repeated behaviors and routines: People with ASDs might repeat actions over and over again. They might want to have routines where things stay the same so they know what to expect. They might have trouble if family routines change. For example, if a child is used to washing his or her face before dressing for bed, he or she might become very upset if asked to change the order and dress first and then wash.

Children with ASDs develop differently from other children. Children without ASDs develop at about the same rate in areas of development such as motor, language, cognitive, and social skills.

Children with ASDs develop at different rates in different areas of growth. They might have large delays in language, social, and cognitive skills, while their motor skills might be about the same as other children their age.

They might be very good at things like putting puzzles together or solving computer problems, but not very good at some things most people think are easy, like talking or making friends.

Children with ASDs might also learn a hard skill before they learn an easy one.

For example, a child might be able to read long words, but not be able to tell you what sound a \"b\" makes. A child might also learn a skill and then lose it. For example, a child may be able to say many words, but later stop talking altogether.

Sources:

Mauk JE, Reber M, Batshaw ML. Autism and other pervasive developmental disorders (4th edition). In: ML Batshaw, editor. Children with disabilities. Baltimore: Paul H. Brookes; 1997.

Powers MD. What is autism? In: MD Powers, editor. Children with autism: a parents\' guide, 2nd edition. Bethesda, MD: Woodbine House; 2000. pp. 1-44.

What conditions are included in ASDs?

ASDs include autistic disorder, pervasive developmental disorder - not otherwise specified (PDD-NOS, including atypical autism), and Asperger disorder.

These three conditions all have some of the same symptoms, but they differ in terms of when the symptoms start, how fast they appear, how severe they are, and their exact nature. These three conditions, along with Rett syndrome and childhood disintegrative disorder, make up the broad diagnosis category of pervasive developmental disorders.

How common are ASDs?

We at CDC do not know how many people in the United States have ASDs. We do know more about children with ASDs than about adults with ASDs. Studies done in Europe and Asia since 1985 have found that as many as 6 of every 1,000 children have at least one ASD. We do have information about how common ASDs are in children in some parts of the United States.

We track the number of children with ASDs and four other disabilities in a five-county area in metropolitan Atlanta (Georgia) through the Metropolitan Atlanta Developmental Disabilities Surveillance Program (MADDSP). In 1996, 3.4 of every 1,000 children 3 through 10 years of age in metropolitan Atlanta had at least one ASD. [Read a summary of the paper about ASD in metropolitan Atlanta - http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12503976&dopt=Abstract]

We have also studied how common ASDs were in Brick Township, New Jersey, in 1998. We found that 6.7 of every 1,000 children 3 through 10 years of age had at least one ASD.

We are now working with several states to learn how many children in other parts of the country have ASDs. These states are developing or improving programs that track the number of children in their areas with ASDs. The program,s began gathering information in 2002, and we expect that they will start reporting findings in late 2003.

We also know that in the United States during the 2000-2001 school year, more than 15,000 children 3 through 5 years of age and more than 78,000 children and adults 6 through 21 years of age were classified as having autism under the Individuals with Disabilities Education Act (IDEA). IDEA is the federal law that supports special education and related services for children and youth with disabilities.

However, there are more children with ASDs who are classified under IDEA in a disability category other than autism. There are, however, some children with ASDs who are not included in these counts, such as children who are in regular education classes, who attend private school, or who are home schooled. [View state-specific IDEA information for children ages 3-5 years http://www.ideadata.org/tables24th/ar_aa2.htm] [View state-specific IDEA information for children ages 6-21 years - http://www.ideadata.org/tables24th/ar_aa3.htm]

We do not know if ASDs are becoming more common in the United States. We do know that today more children are being identified as having an ASD than in the past.

The studies that have looked at how common ASDs are often used different ways to identify children with ASDs, and it is possible that researchers have just gotten better at identifying these children.

It is also possible that professionals know more about ASDs now and are therefore more likely to diagnose them correctly.

Also, a wider range of people are now being classified as having ASDs, including people with very good language and thinking skills in some areas who have unusual ways of interacting or behaving.

Clearly, we have much more to learn. CDC studies in Atlanta and CDC-funded studies in the states will continue over time and will help answer this important question of whether ASDs are truly becoming more common in the United States.

What causes ASDs? Can they be treated?

No one knows exactly what causes ASDs, but scientists think that both genetic and environmental factors might play a role. We do know that parental actions do not cause children to have ASDs.

We are now planning the Children\'s Longitudinal Development Study (CHILD Study), which will look at what factors make it more likely that a child will have an ASD. We are also funding several state projects that will study such factors.

If you would like to learn more about a specific genetic condition that you think could cause an ASD, you can go to the National Library of Medicine\'s Genetics Home Reference Web site. Information on each genetic condition includes symptoms, how common it is, related genes, treatments, and links to resources where you can learn more about the condition. The Genetics Home Reference also can help you learn more about genetics, including genetic testing, genetic counseling, and gene therapy. [Go to the Genetics Home Reference Web site - http://ghr.nlm.nih.gov/ghr/page/Home]

There is no known cure for ASDs. However, early and intensive education can help children grow and learn new skills. The goal of these efforts is to help with the difficult symptoms of an ASD in a child and to improve the child?s skills that help him or her talk, interact, play, learn, and care for his or her needs. Medicines can relieve symptoms and be helpful for some people, but structured teaching of skills (often called behavioral intervention) is currently the most effective treatment.

Sources:

Mauk JE, Reber M, Batshaw ML. Autism and other pervasive developmental disorders, 4th edition. In: ML Batshaw, editor. Children with disabilities. Baltimore: Paul H. Brookes; 1997.

Powers MD. What is autism? In: MD Powers, editor. Children with autism: a parents\' guide, 2nd edition. Bethesda, MD: Woodbine House; 2000. pp. 1-44.

Where can I go to learn more about ASDs?

The links below go to the Web sites of federal agencies or programs that are federally-funded. CDC has no control over the content on these sites. Links to these sites are included for information only. The views and opinions expressed there are not necessarily those of CDC, the Department of Health and Human Services (HHS), or the U.S. Public Health Service (PHS).

Public Health Grand Rounds: Autism Among Us

CDC cosponsored Public Health Grand Rounds on \"Autism Among Us: Rising Concerns and the Public Health Response\" in June 2003. The Grand Rounds covered topics such as:

--- Key behaviors that may suggest a child has an autism spectrum disorder (ASD)

--- The role health care staff providers can play in diagnosing ASDs and other developmental disabilities

--- Possible reasons for the rise in autism diagnoses

--- Community plans for helping children who have an ASD

The Grand Rounds were followed by a 2-week online discussion. [See a video of the Grand Rounds and read the discussion that took place - http://www.publichealthgrandrounds.unc.edu/autism/about.htm]

MEDLINEplus: Autism, Asperger?s Syndrome

MEDLINEplus is an online service of the National Library of Medicine that is designed to link users to information on specific health topics, including autism and Asperger?s syndrome. MEDLINEplus brings together information from many sources and is updated every day.

The site includes information on the latest news, general overviews, projects at the National Institutes of Health, clinical trials, diagnosis and symptoms, rehabilitation, research, specific conditions, treatment, directories, organizations, children, and teenagers. Some of the materials are available in Spanish.

[In English: MEDLINEplus Health Information: Autism]
http://www.nlm.nih.gov/medlineplus/autism.html

[In English: MEDLINEplus Health Information: Asperger?s Syndrome]
http://www.nlm.nih.gov/medlineplus/aspergerssyndrome.html

[En Espa?ol: MEDLINEplus Informaci?n de Salud: Autismo]
http://www.nlm.nih.gov/medlineplus/spanish/autism.html

[En Espa?ol: MEDLINEplus Informaci?n de Salud: S?ndrome de Asperger]
http://www.nlm.nih.gov/medlineplus/spanish/aspergerssyndrome.html

National Center on Birth Defects and Developmental Disabilities (NCBDDD) Publications

NCBDDD staff have written scientific papers on ASDs. These papers look at such topics as how common ASDs are and vaccines. You can see a list of these papers (starting in 1990) by using the keyword search on the NCBDDD publications Web page.

Choose \"autism\" in the keyword box on the search page. You can choose whether you want the list to be sorted by author or by date. You can also choose to have the list appear with or without graphics. Click on the Submit button.

You will see a list of papers that are about ASDs. The list will include the complete reference for each paper and a link to an abstract of the paper or to the full text, when available. [Go to NCBDDD publications keyword search page - http://www2.cdc.gov/ncbddd/pubs/KeywordSearch.asp]

National Information Center on Children and Youth with Disabilities (NICHCY) NICHCY provides information on disabilities and disability-related issues for families, teachers, and other professionals.

NICHCY has a fact sheet about autism that includes information on topics such as characteristics of children with autism, the impact of autism on a child\'s education, and resources. The fact sheet is available in both English and Spanish. [In English: General Information about Autism and Pervasive Developmental Disorder - http://www.nichcy.org/pubs/factshe/fs1txt.htm]
NICHCY also has a more detailed paper about pervasive developmental disorders that includes information about all forms of autism spectrum disorders (ASDs) but focuses mostly on pervasive developmental disorder not otherwise specified (PDD-NOS). The paper has information on the causes, symptoms, diagnosis, and treatment of pervasive developmental disorders.
[Read Pervasive Developmental Disorders paper - http://www.nichcy.org/pubs/factshe/fs20txt.htm]

NICHCY staff will also give information and referrals over the phone (800-695-0285) or by email (nichcy@aed.org).

National Institute of Child Health & Human Development (NICHD)

NICHD has several fact sheets and other publications related to ASD. Some give basic information about ASDs, including symptoms, causes, and treatment. Others talk about vaccines, the role of genetics, and programs funded by NICHD. Many of these materials are available in both English and Spanish. [View list of NICHD ASD publicationshttp://www.nichd.nih.gov/publications/pubskey.cfm?from=autism]

National Institute of Mental Health (NIMH)

NIMH has a booklet about autism that includes sections on what autism is, what causes autism and how it is diagnosed, what other disabilities a child with autism may have, what education and treatment programs are available, what research offers, and where to go for information and support. [Read the NIMH booklet \"Autism\" - http://www.nimh.nih.gov/publicat/autism.cfm]

National Institute of Neurological Disorders and Stroke (NINDS)

NINDS has a fact sheet on autism that includes information on common signs of the condition, diagnosis, causes, treatment, and where to go for more information. The fact sheet includes links to information sheets about pervasive developmental disorders and Asperger disorder. The sheet is available in both English and Spanish.

[In English: Autism fact sheet - http://www.ninds.nih.gov/health_and_medical/pubs/autism.htm]

PubMed

PubMed is an online service of the National Library of Medicine that lets users search scientific journals for articles of interest. You can enter a keyword or the subject you are interested in (for example: \"autism\" or \"asperger\") in the Search box and then click on Go.

You will see a list of matching articles, with links to more information. You can limit your search to certain years, journals, languages, etc., by following the directions given on the PubMed Web site. [Go to PubMed - http://www.ncbi.nlm.nih.gov/entrez/query.fcgi]

All from the CDC - Centers for Disease Control and Prevention (USA):
http://www.cdc.gov/ncbddd/dd/aic/about/default.htm