Diseases & Conditions
This complex developmental disorder of brain function causes impaired social interaction, problems with verbal and nonverbal communication, and unusual or severely limited activities and interests. Symptoms of autism usually appear during the ﬁrst three years of childhood and continue throughout life. Although there is no cure, appropriate early educational intervention may improve social development and reduce undesirable behaviors.
The result of a neurological communication disorder that affects the functioning of the brain, autism and its associated behaviors have been estimated to occur in an estimated 10 to 20 of every 10,000 people, depending on the diagnostic criteria used. Most estimates that include people with similar disorders are two to three times greater. The condition is four times more common in boys than girls and is not related to race, ethnic origin, family income, lifestyle, or education.
Autism signiﬁcantly impairs a child’s ability to communicate and socialize with others. While severity and symptoms vary according to age, the disorder is signiﬁcant and sustained. The mildest forms of autism resemble a personality disorder associated with a perceived learning disability. The most severe cases are marked by extremely repetitive, unusual, self-injurious, and aggressive behavior that may persist and prove very difﬁcult to change, posing a tremendous challenge to those who must live with, treat, and teach these individuals.
Children with autistic disorder demonstrate little interest in friends or social interactions, often failing to develop verbal and nonverbal communication skills. Typically, these children function at a low intellectual level; most experience mild to severe mental retardation. About half of people with autism score below 50 on IQ tests, 20 percent score between 50 and 70, and 30 percent score higher than 70. However, estimating IQ in young children with autism is often difﬁcult because problems with language and behavior can interfere with testing.
However, this is by no means true for all individuals with autistic disorder; the condition may be accompanied by average or strong abilities in an isolated area such as reading or computation. A small percentage of people with autism are savants, with limited but extraordinary skills in areas like music, mathematics, drawing, or visualization.
During the course of childhood and adolescence, children with this condition usually make some developmental gains. Those who show improvement in language and intellectual ability have the best overall outlook. Although some individuals with autism are able to live with some measure of partial independence in adulthood, very few are able to live entirely on their own.
Autism impacts the normal development of the brain in the areas of social interaction and communication skills. Although a single speciﬁc cause of autism is not known, current research links autism to biological or neurological differences in the brain.
Studies of people with autism have found abnormalities in several regions of the brain, including the cerebellum, amygdala, hippocampus, septum, and mamillary bodies. Neurons in these regions appear smaller than normal and have stunted nerve ﬁbers, which may interfere with nerve signaling. These abnormalities suggest that autism results from disruption of normal brain development early in fetal development. Other studies suggest that people with autism have abnormalities of serotonin or other neurotransmitters in the brain. However, these ﬁndings are preliminary and require further study.
In a few cases, disorders such as FRAGILE X SYNDROME, tuberous sclerosis, untreated PHENYLKETONURIA (PKU), and congenital GERMAN MEASLES cause autistic behavior. Other disorders, including TOURETTE’S SYNDROME, LEARNING DISABILITY, and attention deﬁcit disorder often occur with autism but do not cause it. While people with SCHIZOPHRENIA may show some autistic-like behavior, their symptoms usually do not appear until the late teens or early adulthood. Most people with schizophrenia also have hallucinations and delusions, which do not occur in autism.
In many families there appears to be a pattern of autism or related disabilities—which suggests that there is a genetic basis to the disorder. Although at this time no gene has been directly linked to autism, researchers have identiﬁed a number of genes that may play a role in the disorder. Scientists think that the genetic basis is complex and probably involves several combinations of genes.
Scientists estimate that in families with one autistic child, the risk of having a second child with the disorder is about one in 20, which is greater than the risk for the general population. In some cases, parents and other relatives of an autistic person show mild social, communicative, or repetitive behaviors that allow them to function normally but appear to be linked to autism. Evidence also suggests that some emotional disorders occur more frequently than average in families of people with autism.
Autism is NOT a mental illness or a behavior problem, and it is not caused by bad parenting. No known psychological factors in the development of the child have been shown to cause autism.
Characteristics of autism can appear in a wide variety of combinations from mild to severe, but the primary feature of autism is impaired social interaction. Although autism is deﬁned by a certain set of behaviors, children and adults can exhibit any combination of behaviors in any degree of severity. Two children with the same diagnosis can act very differently from one another and have varying skills.
Children and adults with autism typically have problems in verbal and nonverbal communication, social interactions, and leisure or play activities.
• Communication Language develops slowly or not at all; uses words without attaching the usual meaning; communicates with gestures instead of words; short attention span
• Social interaction Spends time alone rather than with others; shows little interest in making friends; less responsive to social cues such as eye contact or smiles
• Sensory impairment May have overly sensitive sight, hearing, touch, smell, and taste
• Play Lack of spontaneous or imaginative play; does not imitate others or initiate pretend games
• Behavior May be overactive or very passive; throw tantrums for no apparent reason; show an obsessive interest in a single item, idea, activity, or person; lack common sense, show aggression, often has difficulty with changes in routine.
The disorder makes it hard for children to communicate with others and relate to the outside world. There may be repeated body movements (hand ﬂapping, rocking), unusual responses to people or attachments to objects, and resistance to changes in routines. In some cases, there may be aggressive or self-injurious behavior. Autism may affect a child’s range of responses and make it more difﬁcult to control how their bodies and minds react. Sometimes visual, motor, or processing problems make it hard for these children to maintain eye contact, and some use peripheral vision rather than looking directly at others. Sometimes touching or being close to others may be painful to a person with autism. Because they cannot make sense of the world in a normal way, people with autism may experience anxiety, fear, and confusion.
In addition, people with autism may have other disorders that affect brain function, such as EPILEPSY, MENTAL RETARDATION, DOWN SYNDROME or genetic disorders such as FRAGILE X SYNDROME or TOURETTE’S SYNDROME.
Symptoms in many children with autism improve with treatment or age. Some people with autism eventually lead normal or near-normal lives. The teen years may worsen behavior problems in some children with autism, who may become depressed or increasingly unmanageable. Parents should be ready to adjust treatment for their child’s changing needs.
Autism is classiﬁed as one of the pervasive developmental disorders. Because it varies widely in its severity and symptoms, autism may go unrecognized, especially in mildly affected individuals or in those with multiple handicaps.
Because there are no medical tests for autism, an accurate diagnosis must be based on observing the person’s communication, behavior, and developmental levels. However, because many of the behaviors associated with autism are similar to other disorders, various medical tests may be ordered to rule out or identify other possible causes of symptoms.
Because the characteristics of the disorder vary, a child should be evaluated by a team including a neurologist, psychologist, developmental pediatrician, speech/language therapist, occupational therapist, or other professionals experienced in autism. Problems in recognizing autism often lead to a lack of services to meet the complex needs of these individuals.
It is important to include history from parents and caregivers in coming to an accurate diagnosis. Some people with autism may seem to have developmental disabilities, a behavior disorder, problems with hearing, or eccentric behavior. It is important to distinguish autism from other conditions, since early identiﬁcation is required for an effective treatment program.
Speciﬁc diagnostic categories have changed over the years as research progresses and as new editions of the DSM (Diagnostic and Statistical Manual) have been issued. Some frequently used criteria include:
• Absence or impairment of imaginative and social play
• Impaired ability to make friends with peers
• Impaired ability to initiate or sustain a conversation with others
• Stereotyped, repetitive, or unusual use of language
• Restricted patterns of interests that are abnormal in intensity or focus
• Apparently inﬂexible adherence to speciﬁc routines or rituals
• Preoccupation with parts of objects
Children with some symptoms of autism, but not enough to be diagnosed with the classical form of the disorder, are often diagnosed with PERVASIVE DEVELOPMENTAL DISORDER—not otherwise speciﬁed (PDD—NOS). People with autistic behavior but well-developed language skills are often diagnosed with ASPERGER SYNDROME. Children who appear normal in their ﬁrst several years but then lose skills and begin showing autistic behavior may be diagnosed with childhood disintegrative disorder (CDD). Girls with RETT SYNDROME, a sex-linked genetic disorder characterized by inadequate brain growth, seizures, and other neurological problems, also may show autistic behavior.
PDD—NOS, Asperger’s disorder, CDD, and Rett syndrome are referred to as “autism spectrum disorders.”
Since hearing problems can be confused with autism, children with delayed speech development should always have their hearing checked, although children may have hearing problems in addition to autism.
While there is no “cure” for the brain abnormalities that cause autism, patients can learn coping mechanisms and strategies to ease various symptoms. With appropriate treatment, many problem behaviors can be changed so that the child may appear to no longer have autism. However, most patients continue to show some faint symptoms to some degree throughout their entire lives. The best-studied therapies include educational/behav-ioral and medical interventions. Although these treatments do not cure autism, they often bring about substantial improvement.
Early intervention is crucial, and can provide dramatic improvements for young children with autism. While various preschool models may differ, all emphasize early, appropriate, and intensive educational interventions for young children. Other common factors may be
• Some degree of inclusion, mostly behaviorally based interventions
• Programs that build on the interests of the child
• Extensive use of visuals to accompany instruction
• Structured activities
• Parent and staff training
• Transition planning
Studies show that individuals with autism respond well to a highly structured, specialized education program tailored to individual needs. A well-designed treatment approach may include work on communication and social skills, sensory integration therapy, and applied behavior analysis by autism experts.
More severely ill children may require a structured, intensive education and behavior program with a one-on-one teacher to student ratio. However, many other children with autism may do well in a normal education environment with appropriate support.
Because of the nature of autism, no single approach can ease symptoms in all cases. Educa-tional/behavioral interventions emphasize highly structured and often intensive skill-oriented training tailored to the individual child. Therapists work with children to help them develop social and language skills. Because children learn most effectively and rapidly when very young, this type of therapy should begin as early as possible. Recent evidence suggests that early intervention has a good chance of favorably inﬂuencing brain development.
In addition, doctors may prescribe a variety of drugs to reduce self-injurious behavior or other troublesome symptoms of autism, as well as associated conditions such as epilepsy and attention disorders. Most of these drugs affect levels of serotonin, dopamine, or other signaling chemicals in the brain.
Many other interventions are available, but few, if any, scientiﬁc studies support their use. These therapies include applied auditory integration training, special diets, discrete trial teaching, music therapy, physical therapy, speech/language therapy, and vision therapy. Some of these treatments are controversial and may or may not reduce a speciﬁc person’s symptoms. Parents should use caution before subscribing to any particular treatment. Counseling for the families of people with autism also may assist them in coping with the disorder.
In addition to an academic program, children with autism should be trained in functional living skills at the earliest possible age. Learning to cross a street, to buy something in a store, or ask for help are critical skills and may be hard even for those with average intelligence. Training is aimed at boosting a person’s independence and providing opportunity for personal choice and freedom.
Contrary to popular belief, many children and adults with autism can make eye contact and can show affection and demonstrate a variety of other emotions in varying degrees. Like other children, they respond to their environment in both positive and negative ways. With appropriate treatment, some behaviors associated with autism may lessen over time. Although communication and social problems will continue in some form throughout life, difﬁculties in other areas may improve with age, education, or stress level. Many individuals with autism enjoy their lives and contribute to their community in a meaningful way, as they learn to compensate for and cope with their disability.
Some adults with autism live and work independently in the community, can drive a car, earn a college degree, and even get married. Some may only need some support for daily pressure, while others require a great deal of support from family and professionals.
Adults with autism may live in a variety of residential settings ranging from an independent home or apartment to group homes, supervised apartment settings, with other family members, or in more structured residential care.
More and more support groups for adults with autism are appearing, and many patients are forming their own networks to share information, support each other, and speak for themselves. Individuals with autism (such as animal scientist Temple Grandin, Ph.D.) are providing valuable insight into the challenges of this disability by publishing articles and books and appearing on TV to discuss their lives and experiences.