Autism Spectrum Disorder (ASD)
ASD is a complex developmental disorder that affects how a person behaves, interacts with others, communicates, and learns. NICHD is one of many federal agencies and NIH Institutes working to understand ASD. NICHD supports and conducts research on what causes autism, how best to detect signs of autism, how best to treat autism and its symptoms, and other topics.
Autism spectrum disorder (ASD) is a complex neurological and developmental disorder that begins early in life and affects how a person acts and interacts with others, communicates, and learns. ASD affects the structure and function of the brain and nervous system. Because it affects development, ASD is called a developmental disorder. ASD can last throughout a person's life.
People with this disorder have problems with:1
- Communication and interaction with other people
- Restricted interests and repetitive behaviors
Different people with autism can have different symptoms. For this reason, autism is known as a spectrum disorder—which means that there is a range of similar features in different people with the disorder.1 This website uses "ASD" and "autism" to mean the same thing.
In giving a diagnosis of ASD, a health care provider will also specify whether the person also has:1
- Intellectual problems, including problems with reasoning or memory
- Language problems, such as problems with speech
- Another medical or genetic condition that is related to or contributes to autism, such as seizures or Fragile X syndrome
In May 2013, a revised version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), the guidelines health care providers use to diagnose different mental health conditions, was released. The DSM-5 made significant changes to how autism is classified and diagnosed.
Now: Under the DSM-5, someone with more severe autism symptoms and someone with less severe autism symptoms both have the same disorder: ASD.
Then: In the previous version of the DSM, ASD was a category and there were four types of autism within the category. These were autistic disorder ("classic" autism), Asperger syndrome (which usually involved milder symptoms, mostly related to social behaviors), childhood disintegrative disorder (in which a child would develop normally for several months or years, then would lose skills related to language, movement and coordination, and other brain functions), and pervasive developmental disorder not otherwise specified (PDD-NOS, or "atypical" autism, which included some, but not all, of the features of classic autism or Asperger syndrome).2
Health care providers no longer use these terms to describe someone with ASD.
The Centers for Disease Control and Prevention tracks the number of people who have ASD. Learn more at https://www.cdc.gov/ncbddd/autism/data.html.
What are the symptoms of autism?
The symptoms of one person with autism can be very different from the symptoms of another person with autism. Health care providers think of autism as a spectrum disorder—which means that there is a range of similar features in different people with the disorder.1
One person with autism may have mild symptoms, while another may have more serious symptoms, but they both have autism spectrum disorder (ASD).
Despite the range of possible symptoms, there are certain actions and behaviors that are common in ASD and could signal that a child is on the autism spectrum. Parents and caregivers who notice these "red flags" should speak to their child's health care provider about autism and screening the child for ASD.
In general, the main signs and symptoms of ASD relate to:
- Communication and interactions with other people
- Routines or repetitive behaviors, sometimes called stereotyped (pronounced STER-ee-uh-tahypt) behaviors
Health care providers organize some noticeable symptoms of autism into "red flags" to help parents and caregivers know what to look for as children grow and develop. These red flags are listed below.
You can find age-specific milestones on the Centers for Disease Control and Prevention website Learn the Signs. Act Early. If your child does not meet developmental milestones, talk to his or her health care provider about screening for ASD.
Note about these red flags:
- Some of these red flags apply only at certain ages, so consider what is typical for other children your child's age.
- Some red flags are more strongly associated with autism than others.
- If your child shows any red flags for autism, talk to his or her health care provider.
When do children usually show symptoms of autism?
The behavioral symptoms of autism spectrum disorder (ASD) often appear early in development.1 Many children show symptoms of autism by 12 months to 18 months of age or earlier.2,3 Some early signs of autism include:4,5,6
- Problems with eye contact
- No response to his or her name
- Problems following another person's gaze or pointed finger to an object (or "joint attention")
- Poor skills in pretend play and imitation
- Problems with nonverbal communication
Many parents are not aware of these "early" signs of autism and don't start thinking about autism until their children do not start talking at a typical age.
What causes autism?
Scientists don't know exactly what causes autism spectrum disorder (ASD).
Autism was first described in the 1940s, but very little was known about it until the last few decades. Even today, there is a great deal that we don't know about autism.
Because the disorder is so complex and no two people with autism are exactly alike, there are probably many causes for autism. It is also likely that there is not a single cause for autism, but rather that it results from a combination of causes.
Scientists are studying some of the following as possible causes of or contributors to ASD.
How do health care providers diagnose autism?
Health care providers look for certain symptoms or groups of symptoms to diagnose autism spectrum disorder (ASD). If you have concerns about your child's development, talk to his or her health care provider right away. The provider then can examine the child and check for specific problems, such as autism.
What are the treatments for autism?
There is currently no one standard treatment for autism spectrum disorder (ASD).
But there are many ways to help minimize the symptoms and maximize abilities. People who have ASD have the best chance of using all of their abilities and skills if they receive appropriate therapies and interventions.
The most effective therapies and interventions are often different for each person. However, most people with ASD respond best to highly structured and specialized programs.1 In some cases, treatment can help people with autism to function at near-normal levels.
Research shows that early diagnosis and interventions, such as during preschool or before, are more likely to have major positive effects on symptoms and later skills. Read more about early interventions for autism.
Because there can be overlap in symptoms between ASD and other disorders, such as attention deficit hyperactivity disorder (ADHD),2 it's important that treatment focus on a person's specific needs, rather than the diagnostic label.
Select the links for more information on each type of treatment for ASD.
- Behavioral management therapy
- Cognitive behavior therapy
- Early intervention
- Educational and school-based therapies
- Joint attention therapy
- Medication treatment
- Nutritional therapy
- Occupational therapy
- Parent-mediated therapy
- Physical therapy
- Social skills training
- Speech-language therapy
If you have a question about treatment, talk to a health care provider who specializes in caring for people with ASD. These resources have more information about treatments for autism:
The Centers for Disease Control and Prevention describes some treatment options.
The Autism Speaks organization offers a Family Services Resources guide. You can search the guide to find autism-related care and services in your area.
Behavioral Management Therapy for Autism
Behavior management therapy tries to reinforce wanted behaviors and reduce unwanted behaviors. It also suggests what caregivers can do before, during, after, and between episodes of problem behaviors.
Behavioral therapy is often based on applied behavior analysis (ABA), a widely accepted approach that tracks a child's progress in improving his or her skills.
Different types of ABA commonly used to treat autism spectrum disorder (ASD) include:
- Positive Behavioral and Support (PBS). PBS aims to figure out why a child does a particular problem behavior. It works to change the environment, teach skills, and make other changes that make a correct behavior more positive for the child. This encourages the child to behave correctly.
- Pivotal Response Training (PRT). PRT takes place in the child's everyday environment. Its goal is to improve a few "pivotal" skills, such as motivation and taking initiative to communicate. These help the child to learn many other skills and deal with many situations.
- Early Intensive Behavioral Intervention (EIBI). EIBI provides individualized, behavioral instruction to very young children with ASD. It requires a large time commitment and provides one-on-one or small-group instruction.
- Discrete Trial Teaching (DTT). DTT teaches skills in a controlled, step-by-step way. The teacher uses positive feedback to encourage the child to use new skills.
Keep in mind that other behavioral therapies, beyond ABA, may also be effective for people with ASD. Talk to your health care provider about the best options for your child.
Cognitive Behavior Therapy for Autism
Cognitive behavior therapy focuses on the connection between thoughts, feelings, and behaviors.
Together, the therapist, the person with autism spectrum disorder (ASD), and/or the parents come up with specific goals for the course of therapy. Throughout the sessions, the person with autism learns to identify and change thoughts that lead to problem feelings or behaviors in particular situations.1,2
Cognitive behavior therapy is structured into specific phases of treatment. However, it is also individualized to patients' strengths and weaknesses. Research shows that this therapy helps people with some types of ASD deal with anxiety. It can also help some people with autism cope with social situations and better recognize emotions.
NICHD Autism Research Goals
NICHD supports and conducts research on a wide range of topics related to autism spectrum disorder (ASD), including genetics, neurodevelopment, screening, and interventions. The overarching aims of this research are to find causes, examine developmental trajectories of the disorder, and develop new or improved interventions or preventions.
Specific objectives include:
- Improving strategies for early screening and diagnosis. Early screening and accurate diagnosis are prerequisites for early intervention, which is the best way to maximize the child's cognitive, social, and language functioning. Tools for screening and diagnosis may include behavioral instruments, biomarkers, imaging methodologies, and others.
- Identifying and characterizing autism susceptibility genes. It is still unclear how the large number of genetic variants associated with ASD increase risk for this condition.
- Understanding the neuropathology of autism and autism-related behaviors.
- Understanding the role of endocrine, metabolic, and immunologic pathways in ASD.
- Detailing the environmental variables that interact with genetic susceptibility factors to produce the ASD phenotype.
- Understanding cognitive, linguistic, and emotional development in autism.
- Testing potential interventions for ASD. These may include drug treatments, dietary interventions, behavioral interventions, and interventions to improve adaptability to various academic, social, and employment environments.
- Developing preventive strategies for ASD.
- Contributing to the overall health and well-being of people with autism throughout the lifespan.
- Developing and supporting research infrastructure to aid in ASD research. This includes autism research networks, training for researchers interested in studying autism, and banks for brain and other tissue.
- Understanding the prevention, etiology, and treatment of conditions and diseases that are commonly comorbid with ASD, such as Fragile X syndrome, anxiety, and epilepsy.
In addition to these goals, NICHD also pursues goals set out by the Interagency Autism Coordinating Committee (IACC) and the NIH Autism Coordinating Committee (NIHACC). Visit https://iacc.hhs.gov/ to review progress reports, as well as the 2013 Update to the IACC Strategic Plan.
Autism Research Activities and Advances
NICHD's autism spectrum disorder (ASD) research portfolio is spread throughout the Institute and includes extramural components that support research on ASD and other intellectual and developmental disabilities (IDDs). NICHD also conducts some autism-related research projects through its intramural program.
In addition, several extramural and intramural entities within NICHD sponsor or conduct research that is not autism-focused but that can inform our understanding of the developmental and molecular processes involved in autism pathophysiology. Some of these efforts are described below.
Early Intervention for Autism
Research shows that early diagnosis of and interventions for autism are more likely to have major long-term positive effects on symptoms and later skills.1,2,3,4,5 Autism spectrum disorder (ASD) can sometimes be diagnosed in children before they are 2 years of age. Some children with ASD whose development seems normal up to that point begin to regress just before or sometime during age 2 years.6
Early interventions occur at or before preschool age, as early as 2 or 3 years of age. In this period, a young child's brain is still forming,7 meaning it is more "plastic" or changeable than at older ages. Because of this plasticity, treatments have a better chance of being effective in the longer term.6 Early interventions not only give children the best start possible, but also the best chance of developing to their full potential. The sooner a child gets help, the greater the chance for learning and progress. In fact, recent guidelines suggest starting an integrated developmental and behavioral intervention as soon as ASD is diagnosed or seriously suspected.6
With early intervention, some children with autism make so much progress that they are no longer on the autism spectrum when they are older. Many of the children who later go off the spectrum have some things in common:3
- Diagnosis and treatment at younger ages
- A higher intelligence quotient (IQ, a measure of thinking ability) than the average child with autism
- Better language and motor skills
To learn more about early intervention services, visit one of the following sites:
- Autism Speaks: Early Intervention Offices by State
- Building the Legacy: IDEA 2004
- Center for Parent Information and Resources
Educational and School-Based Therapies for Autism
Children with autism are guaranteed free, appropriate public education under the federal laws of Public Law 108-177: Individuals with Disabilities Education Improvement Act (2004), sometimes called "IDEA."
IDEA ensures that children diagnosed with certain disabilities or conditions, including autism spectrum disorder (ASD), get free educational services and educational devices to help them to learn as much as they can.
NICHD-funded researchers have also incorporated communications interventions for children with ASD within the classroom setting, with successful outcomes. Although the specific interventions used in the study are not a guaranteed part of IDEA, components from the program could provide an important evidence-based foundation for future school-based therapies.1
Joint Attention Therapy for Autism
Research shows that many people with autism have difficulty with joint attention, which is the ability to share focus on an object or area with another person. Examples of joint attention skills include following someone else's gaze or pointed finger to look at something.
Joint attention is important to communication and language learning. Joint attention therapy focuses on improving specific skills related to shared attention,1 such as:
- Coordinating looks between a person and an object
Improvements from such treatments can last for years.
Other Autism FAQs
Basic information for topics, such as "What is it?" and "How many people are affected?," is available in the About Autism Spectrum Disorder (ASD) section. Other Frequently Asked Questions (FAQs) that are specific to a certain topic are answered in this section.
Medication Treatment for Autism
Currently, there is no medication that can cure autism spectrum disorder (ASD) or all of its symptoms. But some medications can help treat certain symptoms associated with ASD, especially certain behaviors.
NICHD does not endorse or support the use of any medications not approved by the FDA for treating symptoms of autism or other conditions.
Healthcare providers often use medications to deal with a specific behavior, such as to reduce self-injury or aggression. Minimizing a symptom so that it is no longer a problem allows the person with autism to focus on other things, including learning and communication. Research shows that medication is most effective when used in combination with behavioral therapies.1
The U.S. Food and Drug Administration (FDA) has approved the use of some antipsychotic drugs, such as risperidone and aripripazole, for treating irritability associated with ASD in children between certain ages.2 Parents should talk with their child's healthcare providers about any medications for children with ASD.
Other drugs are often used to help improve symptoms of autism, but they are not approved by the FDA for this specific purpose. Some medications on this list are not approved for those younger than 18 years of age. Please consult the FDA for complete information on the medications listed below.
All medications carry risks, some of them serious. Families should work closely with their children's healthcare providers to ensure safe use of any medication.3
- Selective serotonin re-uptake inhibitors (SSRIs)
- This group of antidepressants treats some problems that result from imbalances in the body's chemical systems.
- SSRIs might reduce the frequency and intensity of repetitive behaviors; decrease anxiety, irritability, tantrums, and aggressive behavior; and improve eye contact.
- These medications are another type of antidepressant used to treat depression and obsessive-compulsive behaviors.
- These drugs seem to cause more minor side effects than do SSRIs. They are sometimes more effective than SSRIs for treating certain people and certain symptoms.
- Psychoactive or anti-psychotic medications
- These types of medications affect the brain of the person taking them. The anti-psychotic drug risperidone is approved for reducing irritability in 5-to-16-year-olds with autism.
- These medications can decrease hyperactivity, reduce stereotyped behaviors, and minimize withdrawal and aggression among people with autism.
- This group of medications can help to increase focus and decrease hyperactivity in people with autism. They are particularly helpful for those with mild ASD symptoms.
- Anti-anxiety medications
- This group of medications can help relieve anxiety and panic disorders, which are often associated with ASD.
- These medications treat seizures and seizure disorders, such as epilepsy. (Seizures are attacks of jerking or staring and seeming frozen.)
- Almost one-third of people with autism symptoms have seizures or seizure disorders.
Autism Speaks, one of the leading autism science and family support organizations in the United States, offers a tool to help parents and caregivers make informed decisions about medication. Visit http://www.autismspeaks.org/science/resources-programs/autism-treatment-network/tools-you-can-use/medication-guide for more information.
Creating a Medication Plan
Healthcare providers usually prescribe a medication on a trial basis to see if it helps. Some medications may make symptoms worse at first or take several weeks to work. Your child's healthcare provider may have to try different dosages or different combinations of medications to find the most effective plan.
Families, caregivers, and healthcare providers need to work together to make sure that the medication plan is safe and that all medications have some benefit.
Nutritional Therapy for Autism
For a variety of reasons, children with autism spectrum disorder (ASD) may not get the nutrition they need for healthy growth and development.1,2,3,4 Some children with autism will only eat certain foods because of how the foods feel in their mouths. Other times, they might avoid eating foods because they associate them with stomach pain or discomfort. Some children are put on limited diets in hopes of reducing autism symptoms.
It is important that parents and caregivers work with a nutrition specialist—such as a registered dietitian—or health care provider to design a meal plan for a person with autism, especially if they want to try a limited diet. Such providers can help to make sure the child is still getting all the nutrients he or she needs to grow into a healthy adult, even while on the special diet.
For example, many children with ASD are on gluten-free or casein-free diets. (Gluten and casein are types of proteins found in wheat and milk products, respectively.) Available research data do not support the use of a casein-free diet, a gluten-free diet, or a combined gluten-free, casein-free diet as a primary treatment for individuals with ASD.5
Good Nutrition Is Important
Research shows that children with autism tend to have thinner bones than children without autism.6 Restricting access to bone-building foods, such as dairy products, can make it even harder for their bones to grow strong. Working with a health care provider can help ensure that children who are on special diets still get the bone-building and other nutrients they need.
Digestive Problems in ASD
Some people with autism also have digestive problems, such as constipation, abdominal (belly) pain, or vomiting. Some research7 suggests that digestive problems occur more often in people with autism than in people without autism, but research is still being done on this topic.5,7 Working with a health care provider can help ensure that a diet does not make digestive problems worse.
NICHD and other agencies and organizations will continue research to learn more about how children with autism grow and if they have specific nutritional needs.
Occupational Therapy for Autism
Occupational therapy helps people with autism spectrum disorder (ASD) do everyday tasks by finding ways to work within and make the most of their needs, abilities, and interests.1
An occupational therapist might:1
- Find a specially designed computer mouse and keyboard to ease communication
- Teach personal care skills such as getting dressed and eating
- Do many of the same types of activities that physical therapists do
The American Occupational Therapy Association offers several resources related to occupational therapy and autism .
Parent-Mediated Therapy in Autism
In parent-mediated therapy, parents learn therapy techniques from professionals and provide specific therapies to their own child. This approach gives children with autism spectrum disorder (ASD) consistent reinforcement and training throughout the day. Parents can also conduct some therapies with children who are at risk of autism but are too young to be diagnosed.
Several types of therapies can be parent-mediated activities, including:
- Joint attention therapy
- Social communication therapy
- Behavioral therapy
Studies suggest that parent-mediated therapies might be able to improve the child's communication skills and interactions with others.1 Researchers are still collecting evidence on parent-mediated therapies.2,3,4
Physical Therapy for Autism
Physical therapy includes activities and exercises that build motor skills and improve strength, posture, and balance.
For example, this type of therapy aims to help a child build muscle control and strength so that he or she can play more easily with other children.
Problems with movement are common in autism spectrum disorder (ASD), and many children with autism receive physical therapy.1 However, there is not yet solid evidence that particular therapies can improve movement skills in those with autism.2,3
You can find a physical therapist near you using the American Physical Therapy Association website .
Social Skills Training for Autism
Social skills training teaches children the skills they need to interact with others. It includes repeating and reinforcing certain desired behaviors.
The Children's Friendship Training intervention,1 for instance, helps elementary school-age children improve several social skills:
- Handling teasing
- Being a good sport
- Showing good host behavior during play dates
There are many social skills training programs throughout the United States. For more information on these programs and their effectiveness, visit https://iancommunity.org/cs/what_do_we_know/social_skills_interventions .
Speech-Language Therapy for Autism
Speech-language therapy can help people with autism spectrum disorder (ASD) improve their abilities to communicate and interact with others.1