Autism spectrum disorder is a condition in which people have difficulty developing normal social relationships, use language abnormally or not at all, and show restricted or repetitive behaviors.
Affected people have difficulty communicating with and relating to others.
People with autism spectrum disorder also have restricted patterns of behavior, interests, and/or activities and often follow rigid routines.
Diagnosis is based on observation, reports of parents and other caregivers, and standardized autism-specific screening tests.
Most people respond best to highly structured behavioral interventions.
Autism spectrum disorder (ASD) is a neurodevelopmental condition.
Previously, autism spectrum disorder was subclassified into classic autism, Asperger syndrome, childhood disintegrative disorder, and pervasive developmental disorder not otherwise specified. However, there was so much overlap that it was hard to make distinctions, so doctors no longer use this terminology and consider these all as ASD (except for Rett syndrome, which is a distinct genetic disorder). ASD is different from Rett syndrome, although many people with ASD have both. The classification system emphasizes that, within the broad spectrum, different features may occur more or less strongly in a given individual.
ASD occurs in about 1 of 36 people in the United States and are 4 times more common among boys than among girls. The estimated number of people identified with autism spectrum disorder has risen because doctors and caregivers have learned more about the symptoms of the disorder.
Causes of Autism Spectrum Disorder
The specific causes of autism spectrum disorder are not fully understood, although they are often related to genetic factors. For parents of one child with ASD, risk of having another child with ASD is around 3 to 10%. Several genetic abnormalities, such as Fragile X syndrome, tuberous sclerosis complex, and Down syndrome, may be associated with ASD.
Prenatal infections, for example, viral infections such as rubella or cytomegalovirus, may play a role. Preterm birth (prematurity) may also be a risk factor: the greater the level of prematurity, the greater the risk of ASD.
Some children who have ASD have differences in how their brain is formed and how it functions.
It is clear, however, that ASD is not caused by poor parenting, adverse childhood conditions, or vaccinations (see also MMR vaccine and concerns about autism).
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Symptoms of Autism Spectrum Disorder
Symptoms of autism spectrum disorder may appear in the first 2 years of life, but in milder forms symptoms may not be detected until school age.
Children with autism spectrum disorder develop symptoms in the following areas:
Social communications and interactions
Restricted, repetitive patterns of behavior
Symptoms of ASD range from mild to severe, but most people require some level of support in both areas. People with ASD vary widely in their ability to function independently in school or society and in their need for supports. In addition, up to 20% of children with ASD, particularly those with an IQ less than 50, develop seizures before reaching adolescence. In about 25% of affected children, a loss of previously acquired skills (regression in development) occurs around the time of diagnosis and may be the initial indicator of a disorder.
Social communications and interactions
Often, infants with ASD cuddle and make eye contact in atypical ways. Although some affected infants become upset when separated from their parents, they may not turn to parents for security as do other children. Older children often prefer to play by themselves and do not form close personal relationships, particularly outside of the family. When interacting with other children, they may not use eye contact and facial expressions to establish social contact, and they have difficulty interpreting the moods and expressions of others. They may have difficulty knowing how and when to join a conversation and difficulty recognizing inappropriate or hurtful speech. These factors may cause others to view them as odd or eccentric and thus lead to social isolation.
Language
The most severely affected children never learn to speak. Those who learn may do so much later than normal and use words in an unusual way. They often repeat words spoken to them (echolalia), use memorized scripted speech in place of more spontaneous language, or reverse the normal use of pronouns, particularly using you instead of I or me when referring to themselves. Conversation may not be interactive, and, when present, is used more to label or request than to share ideas or feelings. People with ASD may speak with an unusual rhythm and pitch.
Behavior, interests, and activities
People with ASD are often very resistant to changes, such as new food, toys, furniture arrangement, and clothing. They may become excessively attached to particular inanimate objects. They often do things repetitively. Younger and/or more severely affected children often repeat certain acts, such as rocking, hand flapping, or spinning objects. Some may injure themselves through repetitive behaviors such as head banging or biting themselves. Less severely affected people may watch the same video multiple times or insist on eating the same food every meal. People with ASD often have very specialized, often unusual interests. For instance, a child may be preoccupied with vacuum cleaners.
People with ASD often have over-reactions or under-reactions to sensations. They may be extremely repelled by certain odors, tastes, or textures, or react unusually to painful, hot, or cold sensations that other people find distressing. They may ignore some sounds and be extremely bothered by others.
Intelligence
Many people with ASD have some degree of intellectual disability (an IQ less than 70). Their performance is uneven. They usually do better on tests of motor and spatial skills than on verbal tests. Some people with ASD have idiosyncratic or "splinter" skills, such as the ability to carry out complex mental arithmetic or advanced musical skills. Unfortunately, such people often cannot use these skills in a productive or socially interactive way.
Diagnosis of Autism Spectrum Disorder
A doctor's evaluation
Reports of parents and other caregivers
Standardized autism-specific screening tests
The diagnosis of autism spectrum disorder is made by close observation of the child in a playroom setting and careful questioning of parents and teachers. Standardized autism-specific screening tests, such as the Social Communication Questionnaire for older children and the Modified Checklist for Autism in Toddlers, Revised, with Follow-Up (M-CHAT-R/F), may help identify children who need more in-depth testing. Psychologists and other specialists may use the more extensive Autism Diagnostic Observation Schedules and other tools.
In addition to giving standardized tests, doctors do certain blood or genetic tests to look for underlying treatable or inherited medical disorders, such as hereditary metabolic disorders and Fragile X syndrome.
Treatment of Autism Spectrum Disorder
Applied behavior analysis
Educational programs
Speech and language therapy
Sometimes medication therapy
Applied behavior analysis (ABA) is an approach to therapy in which children are taught specific cognitive, social, or behavioral skills in a stepwise fashion. Small improvements are reinforced and progressively built upon to improve, change, or develop specific behaviors in children who have ASD. These behaviors include social skills, language and communication skills, reading, and academics as well as learned skills such as self-care (for example, showering and grooming), daily-living skills, punctuality, and job competence. This therapy is also used to help children minimize behaviors (for example, aggression) that may interfere with their progress. ABA is tailored to meet the needs of each child and is typically designed and supervised by professionals certified in behavior analysis (such as a board-certified behavior analyst [BCBA]). In the United States, ABA may be available as part of an Individualized Educational Plan (IEP) through schools and in many states is covered by health insurance. Another intensive behaviorally based intervention is the Developmental, Individual-differences, and Relationship-based (DIR®) model, also called Floortime. DIR® draws on the child's interests and preferred activities to help build social interaction skills and other skills. At present, there is less evidence to support DIR/Floortime® than ABA, but both therapies can be effective.
Educational programs for school-aged children with ASD should address social skills development and speech and language delays and help prepare children for education after high school or for employment.
The federal Individuals with Disabilities Education Act (IDEA) requires public schools to provide free and appropriate education to children and adolescents with ASD. Education must be provided in the least restrictive, most inclusive setting possible—that is, a setting where the children have every opportunity to interact with nondisabled peers and have equal access to community resources. The Americans with Disability Act and Section 504 of the Rehabilitation Act also provide for accommodations in schools and other public settings.
Medication therapy cannot change the underlying disorder. However, the selective serotonin
Although some parents try special diets, gastrointestinal therapies, or immunologic therapies, currently there is no good evidence that any of these therapies are helpful in children with ASD. Other complementary therapies, such as facilitated communication, chelation therapy, auditory integration training, and hyperbaric oxygen therapy, have not been proved effective. In considering such treatments, families should consult with the child's primary care physician regarding benefits and risks.
Prognosis for Autism Spectrum Disorder
The symptoms of ASD generally persist throughout life. The prognosis is strongly influenced by how much usable language the child has acquired by elementary school age. Children with ASD who have lower measured intelligence—for example, those who score below 50 on standard IQ tests—are likely to need more intensive support as adults.
More Information
The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
Individuals with Disabilities Education Act (IDEA): A United States law that makes available free appropriate public education to eligible children with disabilities and ensures special education and related services to those children
Americans with Disability Act: A United States law that prohibits discrimination based on disability
Section 504 of the Rehabilitation Act: A United States law that guarantees certain rights to people who have disabilities
These organizations provide support, community, and educational resources for people with and caregivers of people with autism spectrum disorder:
