Autism Spectrum Disorder (ASD)

Autism Spectrum Disorder (ASD) Definition and Facts

Early Screening for Autism Spectrum Disorder
Early screening for autism spectrum disorder may be difficult due to no medical tests such as blood tests.

Autism is a complex developmental disorder that has the following three defining core features:

  1. Problems with social interactions
  2. Impaired verbal and nonverbal communication
  3. A pattern of repetitive behavior with narrow, restricted interests

A number of other associated symptoms frequently coexist with autism.

  • Most people with autism have problems using language, forming relationships, and appropriately interpreting and responding to the external world around them.
  • Autism is a behaviorally defined developmental disorder that begins in early childhood.
  • Although the diagnosis of autism may not be made until a child reaches preschool or school age, the signs and symptoms of autism may be apparent by the time the child is aged 12-18 months, and the behavioral characteristics of autism are almost always evident by the time the child is aged 3 years.
  • Language delay in the preschool years (younger than 5 years) is typically the presenting problem for more severely affected children with autism. Higher functioning children with autism are generally identified with behavioral problems when they are aged approximately 4-5 years or with social problems later in childhood.
  • Autism disorder persists throughout the person's lifetime, although many people are able to learn to control and modify their behavior to some extent.

As of May 2013, autism, along with what was formally described as Asperger's syndrome and pervasive developmental disorders were classified by the American Psychiatric Association as autism spectrum disorders (ASDs).

All of these disorders are characterized by varying degrees of problems with communication, social interaction, and atypical, repetitive behaviors.

There is a wide range of symptoms, severity, and other manifestations of these disorders. The expression of autism spectrum disorders varies widely among affected individuals. A child with significant impairment in all three of the core functioning areas (socialization, communication, and atypical, repetitive behaviors) may have a lower level-functioning autism spectrum disorder, while a child with similar problems but without delays in language development may have a higher level-functioning autism spectrum disorder.

Some people are affected with fairly mild symptoms and signs of autism. Many of these individuals learn to live independent lives. Others are more severely affected and require lifelong care and supervision.

As the following statistics indicate, autism is a common developmental disorder.

  • The number of children diagnosed with autism spectrum disorders appears to be increasing. Although there is a concern that the actual number of children with autism spectrum disorders is increasing, several factors, such as improvements in diagnostic methods and the view of autism spectrum disorders as being on a continuum, also may account for the increase.
  • Autism affects all races, ethnic groups, and socioeconomic levels.
  • Boys are more likely than girls to have autism.

There is no cure for autism; however, there is good news.

  • A generation ago, most children with autism were institutionalized. This is no longer the case and most children with this disorder live with their families.
  • Our improving understanding of autism has shown that, regardless of the severity of the condition, appropriate treatment and education can eventually help many children with autism to be integrated into their community.
  • Early diagnosis is essential for implementing appropriate treatment and education at an early age when they can do the most good.

What Is Autism Spectrum Disorder (ASD)?

Autism spectrum disorder (ASD) refers to a group of complex neurodevelopment disorders characterized by repetitive and characteristic patterns of behavior and difficulties with social communication and interaction. The symptoms are present from early childhood and affect daily functioning.

The term "spectrum" refers to the wide range of symptoms, skills, and levels of disability in functioning that can occur in people with autism spectrum disorder.

Some children and adults with autism spectrum disorders are fully able to perform all activities of daily living while others require substantial support to perform basic activities. The Diagnostic and Statistical Manual of Mental Disorders (DSM-5, published in 2013) includes Asperger syndrome, childhood disintegrative disorder, and pervasive developmental disorders not otherwise specified (PDD-NOS) as part of autism spectrum disorder rather than as separate disorders. A diagnosis of autism spectrum disorder includes an assessment of intellectual disability and language impairment.

What Is the Main Cause Autism?

Although autism is the result of a neurologic abnormality, the cause of these problems with the nervous system is unknown in most cases. Research findings indicate a strong genetic component. Most likely, environmental, immunologic, and metabolic factors also influence the development of the disorder.

  • There is probably no single gene or genetic defect that is responsible for autism. Researchers suspect that there are a number of different genes that, when combined together, increase the risk of getting autism. In families with one child with autism, the risk of having another child with autism is low. The concordance of autism in monozygotic twins is significant. A number of studies have found that first-degree relatives of children with autism also have an increased risk of autism spectrum disorders.
  • In some children, autism is linked to an underlying medical condition. Examples include;
    • metabolic disorders (untreated phenylketonuria [PKU]),
    • congenital infections (rubella, cytomegalovirus [CMV], toxoplasmosis),
    • genetic disorders (fragile X syndrome, tuberous sclerosis),
    • developmental brain abnormalities (microcephaly, macrocephaly, cerebral dysgenesis), and
    • neurologic disorders acquired after birth (lead encephalopathy, bacterial meningitis). These medical disorders alone do not cause autism as most children with these conditions do not have autism.
  • Environmental factors and exposures may interact with genetic factors to cause an increased risk of autism in some families.

Over time, many different theories have been proposed about what causes autism. Some of these theories are no longer accepted, however;

  • Emotional trauma: Some believed that emotional trauma at an early age, especially bad parenting, was to blame. This theory has been rejected.
  • Vaccines: Although the mercury preservative used in some vaccines is known to be neurotoxic, the most recent research on this subject does not suggest a specific link between vaccines and autism. Except for some influenza (flu) multidose preparations, thimerosal was removed from or reduced in all vaccines routinely recommended for children 5 years of age and under manufactured for the U.S. market in 2001.

What Are Early Signs and Symptoms of Autism? Which Ones Are Myths?

Autism is a condition surrounded by myths and generalizations about people with autism that are rarely appropriate. The common beliefs that people with autism are myths. For example;

  • never expresses emotion,
  • never smiles or laughs,
  • never makes eye contact, never talks, and
  • never display affection.

Just as every person is unique, with his or her personality and characteristics, every person with autism manifests the disorder in his or her unique way.

The list of symptoms and behaviors associated with autism is long, and each affected person expresses his or her combination of these behaviors. None of these clinical features is common to all people with autism, and many are occasionally exhibited by people who are not autistic.

All people with autism have abnormal functioning in three core areas of development:

  1. social interaction,
  2. verbal and nonverbal communication, and
  3. the presence of repetitive and restricted patterns of behavior, interests, and activities.

The diagnosis of autism is typically made when impairment is significant in all three areas, with impairments in social interaction and communication being one rather than two categories of impairment according to the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-V, American Psychiatric Association 2013).

Impaired reciprocal social interaction

Examples include the following:

  1. poor use of body language and nonverbal communication, such as eye contact, facial expressions, and gestures;
  2. lack of awareness of feelings of others and the expression of emotions, such as pleasure (laughing) or distress (crying), for reasons not apparent to others;
  3. remaining aloof, preferring to be alone;
  4. difficulty interacting with other people and failure to make peer friendships;
  5. may not want to cuddle or be cuddled;
  6. lack of or abnormal social play;
  7. not responding to verbal cues (acting as if deaf).

Impaired communication

Examples include the following:

  1. delay in, or the total lack of, the development of spoken language or speech;
  2. if speech is developed, it is abnormal in content and quality;
  3. difficulty expressing needs and wants, verbally and/or nonverbally;
  4. repeating words or phrases back when spoken to (known as echolalia);
  5. inability to initiate or sustain conversation;
  6. absent or poorly developed imaginary play.

The restricted repertoire of interests, behaviors, and activities

Examples include the following:

  1. insisting on following routines and sameness, resisting change;
  2. ritualistic or compulsive behaviors;
  3. sustained odd play;
  4. repetitive body movements (hand flapping, rocking) and/or abnormal posture (toe walking);
  5. preoccupation with parts of objects or a fascination with repetitive movement (spinning wheels, turning on and off lights);
  6. narrow, restricted interests (dates/calendars, numbers, weather, movie credits).

There are several associated features and behaviors that are seen in some people with autism, including the following:

Cognitive function: Autism occurs at all intelligence levels. Although about 75% of autistic individuals have an intelligence quotient (IQ) below average, the other 25% have an average or above-average intelligence. The performance IQ is generally higher than the verbal IQ. A small percentage have high intelligence in a specific area such as mathematics.

Neurologic function

  1. Seizures may develop in a significant percentage of children with autism and can be resistant to treatment. The onset of seizures peaks in early childhood and again in adolescence. There is an increased risk of seizures in children with autism who have mental retardation or a family history of autism.
  2. Uneven gross and/or fine motor skills (well developed in some areas, poorly developed in others)

Behavioral symptoms include:

  1. aggressive or self-injurious behavior;
  2. noticeable extreme underactivity or overactivity;
  3. throwing tantrums;
  4. short attention span;
  5. abnormal responses to sensory stimuli (for example, expressing over sensitivity or under sensitivity to pain);
  6. abnormalities in eating or sleeping;
  7. not responding to normal teaching methods;
  8. playing in odd or unusual ways;
  9. having inappropriate attachment to objects;
  10. having no apparent fear of dangerous situations.

Mood and affect

  1. Mood and affect vary considerably and may include being unaware of the feelings of others, withdrawn, or emotionally labile. Some people with autism become outwardly anxious or they may become depressed in response to the realization of their problems.
  2. In some children with autism who express affection, the affection may be indiscriminate.

When Should You Call a Doctor for Autism in Infants and Toddlers?

If an infant or toddler exhibits any unusual behaviors for a day or two after behaving completely normally, it probably means that he or she is coming down with a minor illness, doesn't feel well, or is tired or under some other form of stress. However, if the child has always had any of these characteristics, or the characteristic(s) continues over a period of time, a visit to the pediatrician or other health care provider is warranted. The average age for the diagnosis of autism is 4 to 6 years, although most parents suspected something was wrong by 18 months and voiced their concerns by age 2 years.

Some examples of behaviors that warrant seeking medical care include:

  • seems distant or oblivious to surroundings;
  • doesn't play or interact well with others;
  • is uncommunicative;
  • has problems speaking or understanding the speech of others;
  • has uncontrollable temper tantrums;
  • insists on sameness and routine;
  • engages in repetitive or compulsive actions.

Based on an understanding of potential early autism symptoms, the National Institute of Child Health and Human Development (NICHD) and experts recommend that babies or children be evaluated for autism who have not met the following developmental milestones:

  • Not babbled or cooed by age 1 year
  • Not gestured, pointed, or waved as an infant, by age 1 year
  • Not spoken a single word by age 16 months
  • Not spoken a 2-word phrase by age 2 years
  • Experiences any loss of language or social skills at any age

If even one of these statements is true of a child, parents should resist the temptation to "just wait and see." Problems of this type may signal some type of disability, even if it is not autism. Prompt diagnosis and early intervention are very important in improving the long-term outcomes for developmental disorders of all types, including autism.

What Questions Should You Ask the Doctor about Autism in Children?

  • Is my child's development on target for his or her age?
  • Are my child's social skills developing normally?
  • What further evaluation and testing are necessary to evaluate my child for possible autism?
  • What resources are available to support our child and family?

What Procedures and Tests Diagnose Autism?

  • There is no lab test or X-ray that can confirm the diagnosis of autism. The diagnosis of autism is based on clinical judgment regarding observations of the individual's behavior. Information from family members and other observers is of primary importance in making the diagnosis; however, the pediatrician may order tests to rule out other conditions that might be confused with autism, such as mental retardation, metabolic or genetic diseases, or deafness.
  • A single visit with the pediatrician is not enough to establish the diagnosis of autism.
  • The pediatrician observes the child and may do a simple screening test to see if a developmental problem may be present.

Screening tests do not diagnose autism. Done in the office, they are simple tests that indicate a problem may exist. They usually involve simply observing specific behaviors (for very young children) or how a child responds to simple commands or questions (for older children). Some widely used screening tests include the Checklist for Autism in Toddlers (CHAT) for children aged 18 months to 4 years of age and the Autism Screening Questionnaire for children aged 4 years and older.

  • Other conditions must be ruled out, and the diagnosis of autism must be established with certainty before treatment begins.
  • If the pediatrician believes that further evaluation is necessary, he or she will refer the child to a professional who specializes in developmental disorders. This specialist may be a developmental pediatrician, a child psychiatrist, a pediatric neurologist, or a child psychologist.
  • Other professionals, such as speech and language pathologists, audiologists (specialists in testing hearing), occupational therapists, physical therapists, and social workers, may be involved in the evaluation process.

The comprehensive evaluation of a child with autism might include:

  • obtaining complete medical and family history;
  • physical exam;
  • formal audiology evaluation;
  • selected medical/lab tests on an individual basis (for example, lead levels, genetic tests, metabolic tests, brain MRI, electroencephalogram [EEG]);
  • speech, language, and communication assessment;
  • cognitive and behavioral assessments (focus on social skills and relationships, problem behaviors, motivation and reinforcement, sensory functioning, and self-regulation); and
  • academic assessment (educational functioning, learning style).

What Is the Treatment for Autism?

Treatment strategies used in autism include behavioral, educational, biomedical, and complementary therapies. Some of these are supported by scientific studies, while others are not. It is important to discuss and consider the research support for the treatments chosen. Once treatment begins, the multidisciplinary team will recommend regular assessments to check your child's progress. These should be built into the treatment plan.

A pediatrician will refer the caregiver and the child to a specialist in developmental disorders for the assessment. Some people may want to have this specialist treat their child's condition, but they are free to seek treatment elsewhere.

  • There is no standard treatment for autism, and different professionals have different philosophies and practices in caring for their patients.
  • You may want to talk to more than one specialist to find the one with whom you feel most comfortable.
  • Ask family members, friends, and the health care practitioner to obtain referrals. Call autism groups or check the Internet for referral services.

When seeking a specialist to treat a child's autism, the opportunity should be available to ask questions and discuss the treatments available to the child. Be aware of all the options so that an informed decision can be made.

A reputable specialist will present each type of treatment, provide the pros and cons, and make recommendations based on published treatment guidelines and his or her own experience.

  • The decision of which treatment to pursue is made with this specialist (with input from other members of the professional care team) and family members, but the decision is ultimately the caregivers'.
  • Be certain to understand exactly what will be done and why, and what can be expected from the choices.

There is no cure for autism, nor is there a standard therapy that works for all people with autism. Several different treatment approaches have evolved as we have learned more about autism.

  • Different approaches work for different people. Accepted interventions may work for some and not for others.
  • Different professionals, each with excellent credentials and experience, may disagree about what is the best approach for the child.
  • As a parent or caregiver, one will learn to weigh each treatment recommendation in light of what he or she knows about their child and what makes sense for him or her.
  • Whatever approach is used for the child, an individualized treatment plan designed to meet his or her unique needs is essential.
  • Most people with autism show developmental progress and respond to a combination of treatment and education.
  • The traditional approach for a child with autism includes special education and behavioral management. There is some evidence that the earlier behavioral, educational, speech, and occupational therapy is begun, the better the long-term outcome. This is often an intensive and long-term commitment, and there is no easy answer. Behavioral treatments, medications, and other treatments may help manage some of the problems associated with autism.

The best thing you can do to help your child is to work with a professional team. Be informed of the issues surrounding your child's treatment and outlook. Be sure you are clear about the goals of therapy and how they are to be achieved. Be organized and cooperative in supplying all information required by the team. Communicate your questions and reservations about the treatment plan so they can be addressed.

What Medications Treat the Signs and Symptoms of Autism?

Many different biomedical treatments are used in autism. The most widely used are medications to treat seizures and behavioral and emotional problems associated with autism.

Medication does not treat the underlying neurologic problems associated with autism. Rather, medication is given to help manage behavioral manifestations of the disorder, such as hyperactivity, impulsivity, attention difficulties, and anxiety. In most cases, medication is given to lessen these problems so that the person can receive maximum benefit from behavioral and educational approaches.

Medications used in autism are psychoactive, meaning they affect the brain. Those used most often include the following:

These medications should be prescribed only by a medical professional experienced in treating persons with autism.

What Vitamins, Minerals, and Diet Changes Treat Autism Signs and Symptoms?

Although many studies have been done to assess whether abnormal amounts of vitamins, minerals, or other nutrients can be found in people with autism, results have not clearly pointed to any abnormalities that are consistently linked with the disorder. Although few, if any, of these claims are backed up by scientific studies, parents and physicians alike have reported improvement in symptoms in people given certain supplements, including vitamin B, magnesium, cod liver oil, and vitamin C.

Some people with autism have food sensitivities and food allergies and dietary management is important in these cases to maintain nutrition and health. Another focus of dietary therapy is on problems with intestinal digestion and absorption of nutrients in foods suspected to be present in some individuals with autism. Some parents and professionals have reported improvements in symptoms of autism when diets eliminating suspect proteins, such as gluten (found in wheat flour), are consistently followed. However, there are no scientific studies to confirm their effectiveness.

Do not start giving a child supplements or dramatically change his or her diet without discussing it with the treatment team. It is important to maintain adequate nutrition to ensure optimal growth and development. Furthermore, although vitamins, minerals, and many other substances available as supplements are necessary for body functions, some of them can be dangerous if taken in excess.

What Behavioral Therapies Treat Autism Signs and Symptoms in Toddlers and Children?

Behavioral therapies

Behavioral therapy is the foundation for most treatment programs for children with autism. More than 30 years of research has shown the benefit of applied behavioral methods in improving communication, learning, adaptive behavior, and appropriate social behavior while reducing inappropriate behavior in children with autism. There is strong evidence that these interventions are most effective when started early, typically in the preschool years. A range of scientifically supported behavioral treatments has been developed that may be helpful for some children with autism. These are mainly based on the principles of applied behavior analysis.

Applied behavior analysis (ABA) is designed to both correct behaviors and teach skills for dealing with specific situations. It is based on the principle of reinforcement: that behavior can be changed by rewarding desired behavior and removing reinforcement for unwanted behavior. The person will naturally repeat behaviors for which he or she is rewarded. This principle is applied in many different ways, such as discrete trial training, incidental teaching, errorless learning, and shaping and fading. Most treatment programs include a number of ABA therapies.

These comprehensive treatment approaches differ in their specifics but are highly structured, intensive programs in which the child spends a large amount of time (15-40+ hours per week), usually in one-to-one activities with a therapist, to change behaviors. Behavioral therapists typically collaborate with parents, school personnel, and community professionals in providing a comprehensive treatment program that is individualized to meet each child's specific needs.

Positive behavioral interventions and support are designed to replace problem behaviors with positive behaviors and improve the person's quality of life. Like other approaches, this approach requires examination of the individual's unique strengths and problems and the development of strategies to improve his or her quality of life overall.

What Educational and Complementary Therapies Are Used to Treat Autism?


The main principle of education is that each person with autism has his or her own strengths, abilities, and functional level and that his or her education should be tailored to meet his or her individual requirements. This is not only desirable for the child, it is required by federal law. The Individuals with Disabilities Education Act (IDEA; P.L.101-476) guarantees free and appropriate public education for every child with a disability. This law specifies that a written and explicit education plan (the Individualized Education Plan, or IEP) be prepared by the local education authority in consultation with the child's parents. When all parties agree on the plan, the plan must be put into place and the child's progress documented. Preparation of the plan includes a comprehensive assessment of the child's needs.

Many different options are available for educating children with autism. The basic assumption is that, whenever possible, children with disabilities should be educated with their nondisabled peers, who serve as models for appropriate language, social, and behavioral skills. Thus, some children with autism are educated in mainstream classrooms, others in special education classes within mainstream public schools, and others in specialized programs separate from mainstream public schools. Parents wanting to find the best possible program for their child are advised to work with the local education authority; full cooperation and communication are essential for meeting this goal.

The following specific programs have been developed for persons with autism:

  • TEACCH is a program developed in North Carolina and is used statewide for people with autism. It encompasses many different theories and techniques to develop an individualized program for each person with autism. The underlying principle is that the environment should be adapted for the person with autism, not the other way around. This program focuses less on changing specific behaviors and more on providing the child with the skills needed to understand his or her environment and communicate his or her needs.
  • Floortime is an approach that helps the child with autism progress on the natural developmental ladder. It is based on the theory that children cannot progress to advanced learning until they have completed all the required steps of this ladder, and that children with autism have not completed the ladder.
  • A social story is an approach that uses stories to teach children social skills. In each story, a person is faced with a situation or event; the story is intended to help the child with autism understand the thoughts and emotions of the person in the story. This helps the child develop an understanding of the appropriate or expected response to the situation. The stories are tailored to the individual and often include music and illustrations.

It is important that skills learned at school are generalized outside the classroom setting. Thus, programs for children with autism must include the family and be coordinated across the child's home and community.

Complementary therapies

Complementary therapies include art therapy, music therapy, animal therapy, and sensory integration therapy. These are not behavioral or educational approaches per se, but they provide another opportunity for the child to develop social and communication skills. Although there is little scientific evidence that these therapies increase skills, many parents and therapists describe noticeable improvements in a child's behavior and communication abilities, as well as a sense of enjoyment.

Complementary therapies are typically used in addition to behavioral and educational approaches.

  • Art therapy offers the child a nonverbal way to express his or her feelings.
  • Music therapy involving singing helps develop the child's speech and language skills.
  • Animal therapy, such as horseback riding and swimming with dolphins, improves the child's motor skills while increasing self-confidence.
  • Sensory integration focuses on normalizing extreme reactions to sensory input. It tries to help the child reorganize and integrate his or her sensory information so he or she can better understand the external world.

What Is the Prognosis for Autism? Can It Be Cured?

Although, to different degrees of severity, the core features of autism are life-long, predicting the course for an individual with autism is very difficult. Many different variables enter into each person's experience with autism, including the symptoms and associated behaviors and their severity, the family environment, and the types of interventions used. An individual's IQ (particularly verbal IQ) is often a predictor of future functioning, with increasing IQ and communication skills associated with an increased ability to live independently. Some people with autism are able to develop their communication and social skills to a degree that allows them a fair degree of independence. Others can learn some skills but still require ongoing support from their family and others throughout their lives.

There is no cure for autism.

Can Autism Be Prevented?

There is no known way to prevent autism. Research into the genetics of autism may eventually offer interventions that can correct genetic errors before the signs and symptoms of autism develop.

Where Can I Get Information about Support Groups and Counseling for Autism?

Having a child diagnosed with autism can be a devastating experience for many parents and families. They may feel frustrated, confused, and afraid they may even "grieve" for their "normal child."

Living with autism presents many new challenges for the person with autism and for his or her family and friends.

Parents of autistic children certainly have many worries. They wonder if their children will be able to achieve, if they will be able to be independent, and if they will be able to be happy and enjoy life. Parents also probably have many worries about how autism will affect them and their ability to live a normal life, that is, to care for their family and home, to hold a job, and to continue the friendships and activities they enjoy. Many people feel anxious and depressed. Some people feel angry and resentful; others feel helpless and defeated.

For most people who have a child with autism, and even for some with autism themselves, talking about their feelings and concerns helps.

Friends and family members can be very supportive. They may be hesitant to offer support until they see how you are coping. Don't wait for them to bring it up. If you want to talk about your concerns, let them know.

Some people don't want to burden their loved ones, or they prefer talking about their concerns with a more neutral professional. A family therapist, social worker, counselor, or member of the clergy can be helpful if you want to discuss your feelings and concerns about your child's autism. Your health care practitioner should be able to recommend someone.

Many people who have a child with autism are profoundly helped by talking to other people in the same situation. Sharing your concerns with others who have been through the same thing can be remarkably reassuring. Support groups for families affected by autism may be available through the organizations providing treatment and education for your child.

For information about support groups in the area for families with an autistic child, contact the following organizations:

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Asperger's Syndrome Signs and Symptoms in Infants, Children, and Toddlers

Common signs and symptoms of Asperger's syndrome in infants, toddlers, and children include:

  1. Social problems
  2. Abnormal communication patterns
  3. Sensory sensitivity
  4. Intense interest in a particular that is often very restricted or an immature subject that dominates the person's attention
Arehart-Treichel J. Autism treatment arsenal expands, with more options on horizon. Psychiatric News 2010 May 21; 45(10): 20.

Williams E. A comparative review of early forms of object-directed play and parent-infant play in typical infants and young children with autism. Autism 2003; 7; 361-377.