What is autism?

Who gets autism?

ASDs occur in all racial, ethnic, and socioeconomic groups and are four times more likely to occur in boys than in girls. CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network released data in 2007 that found about 1 in 150 8-year-old children in multiple areas of the United States had an ASD.

We have learned a lot about the symptoms of ASDs and have improved efforts to track the disorders, but we still don’t know a lot about the causes of ASDs. Scientists think that both genes and the environment play a role, and there might be many causes that lead to ASDs. 

Family studies have been most helpful in understanding how genes contribute to autism. Studies have shown that among identical twins, if one child has autism, then the other will be affected about 75% of the time. In non-identical twins, if one child has autism, then the other has autism about 3% of the time. Also, parents who have a child with an ASD have a 2%–8% chance of having a second child who is also affected.[5],[6]

For most people with ASDs, the cause is not known. But ASDs tend to occur more often than expected among people who have certain other medical conditions, including Fragile X syndrome, tuberous sclerosis, congenital rubella syndrome, and untreated phenylketonuria (PKU). Some harmful drugs taken during pregnancy also have been linked with a higher risk of autism, specifically, the prescription drug thalidomide.

CDC’s Centers for Autism and Developmental Disabilities Surveillance and Epidemiology (CADDRE) are working together on a large, population-based study to better understand the possible risk factors for and causes of autism. Called the Study to Explore Early Development (SEED), this project will help answer the many questions regarding the causes of autism.

Children with autism tend to have some level of deficit in some or all of the following areas:

Social Skills
Social impairments are one of the main problems in all of the autism spectrum disorders (ASDs). People with ASDs do not have merely social “difficulties” like shyness. Their severe social impairments often cause serious problems in everyday life. These social problems are often combined with the other areas of deficit, such as communication skills and unusual behaviors and interests. For instance, the inability to have a back-and-forth conversation is both a social and a communication problem.

Typical infants are very interested in the world and people around them. By the first birthday, a typical toddler tries to imitate words, uses simple gestures such as waving “bye bye,” grasps fingers, and smiles at people. But the young child with autism may have a very hard time learning to interact with other people. One way very young children interact with others is by imitating actions—for instance, clapping when mom claps.  Children with ASDs may not do this, and they may not show interest in social games like peek-a-boo or pat-a-cake. Although the ability to play pat-a-cake is not an important life skill, the ability to imitate is. We learn all the time by watching others and by doing what they do—especially in new situations and in the use of language.

People with ASDs might not interact with others the way most people do. They might not be interested in other people at all. Some might want friends but have social problems that make those relationships difficult. They might not make eye contact and might just want to be alone. Many children with ASDs have a very hard time learning to take turns and share—much more so than other children. This can make other children unwilling to play with them.

People with ASDs may have problems with expression, so they might have trouble understanding other people's feelings or talking about their own feelings. Many people with ASDs are very sensitive to being touched and might not want to be held or cuddled. Self-stimulatory behaviors, common among people with ASDs, may seem odd to others or make them uncomfortable, causing them to shy away from a person with an ASD. 

Social issues such as trouble interacting with peers, saying whatever comes to mind even if it’s inappropriate, difficulty adapting to change, and even poor grooming habits can sometimes make it hard for adults with ASDs  to get and/or  keep a job at their intellectual level. Anxiety and depression, which affect some people with ASDs, can make existing social impairments even harder to manage.

Social skills that many people learn by watching others may need to be taught directly to people with ASDs. When deciding what to teach, remember the social value of learning independent living skills such as toilet training and other basic grooming skills (bathing, tooth brushing, dressing appropriately, etc.). Click here to learn more about autism treatment.

Because children and adolescents with ASDs are “different,” and because they are often very literal and sometimes naïve and overly trusting, they are often the target of bullies and might be easily taken advantage of. It is very important to teach all children from a very young age to be tolerant and accepting of differences. It is also important to teach children and adolescents with ASDs about personal safety and tell them to go to a parent, teacher, or other trusted adult if they need help. 

There are many strategies and curriculum supplements for teaching children and adolescents with and without ASDs about bullying and other personal safety issues.  These can be found by visiting a local bookstore, searching an online book seller, or by contacting a publishing company that specializes in disability-specific and/or education publications. Teachers and health care professionals are often good resources for this type of information as well.

For more examples of the social issues related to ASDs, click here.

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Communication
Each person with an ASD has different communication skills. Some people may have relatively good verbal skills, with only a slight language delay with impaired social skills. Others may be not speak at all or have limited ability or interest in communicating and interacting with others. About 40% of children with ASDs do not talk at all. Another 25%–30% of children with autism have some words at 12 to 18 months of age and then lose them.[1] Others may speak, but not until later in childhood.

People with ASDs who do speak may use language in unusual ways. They may not be able to combine words into meaningful sentences. Some people with ASDs speak only single words, while others repeat the same phrases over and over. Some children repeat what others say, a condition called echolalia. 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 might repeat "Do you want some juice?" instead of answering your question. Although many children without ASDs go through a stage where they repeat what they hear, it normally passes by age 3. Some people with ASDs can speak well but may have a hard time listening to what other people say.

People with ASDs may have a hard time using and understanding gestures, body language, or tone of voice. For example, people with ASDs might not understand what it means to wave goodbye. Facial expressions, movements, and gestures may not match what they are saying. For instance, people with ASDs might smile while saying something sad. They might say "I" when they mean "you," or vice versa. Their voices might sound flat, robot-like, or high-pitched. 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. They might talk a lot about something they really like, rather than have a back-and-forth conversation with someone. Some children with relatively good language skills speak like little adults, failing to pick up on the “kid-speak” that is common in their peers.

For more examples of the communication issues related to ASDs, click here.

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Repeated Behaviors and Routines
Unusual behaviors such as repetitive motions may make social interactions difficult.

Repetitive motions are actions repeated over and over again. They can involve part of the body or the entire body or even an object or toy. For instance, people with ASDs may spend a lot of time repeatedly flapping their arms or rocking from side to side. They might repeatedly turn a light on and off or spin the wheels of a toy car in front of their eyes. These types of activities are known as self-stimulation or “stimming.”

People with ASDs often thrive on routine. A change in the normal pattern of the day—like a stop on the way home from school—can be very upsetting or frustrating to people with ASDs. They may “lose control” and have a “melt down” or tantrum, especially if they’re in a strange place.

Also, some people with ASDs develop routines that might seem unusual or unnecessary. For example, a person might try to look in every window he or she walks by in a building or may always want to watch a video in its entirety—from the previews at the beginning through the credits at the end. Not being allowed to do these types of routines may cause severe frustration and tantrums. 

No two people with ASDs are exactly alike. So, each person with an ASD needs a treatment program to meet his or her individual needs and the needs of his or her family.  While there is not yet a cure for ASDs, early, intensive treatment can help children with the disorder reach their full potential. Acting early can make a big difference! For guidance on choosing a treatment program, visit the Treatment Options section of the National Institute of Mental Health’s autism website.

It is important to remember that children with ASDs can get sick or injured just like children without ASDs. Regular medical and dental exams should be part of a child’s intervention plan. Often it is hard to tell if a child’s behavior is related to the ASD or is caused by a separate health condition. For instance, head banging could be a symptom of the ASD, or it could be a sign that the child is having headaches. In those cases, a thorough physical exam is needed.

Even if your child has not been diagnosed with an ASD, he or she may be eligible for early intervention services. The Individuals with Disabilities Education Act (IDEA) says that children under the age of 3 who are at risk of having substantial developmental delays may be eligible for services. These services are provided through an early intervention system in your state. Through this system, you can ask for an evaluation. To learn more about early intervention, click here National Dissemination Center for Children with Disabilities.

• Behavioral and Educational Interventions
• Complementary and Alternative Medicine
• Dietary Changes
• Medications
• Additional Treatment Resources