Autism is classified by the American Psychiatric Association as a pervasive developmental disorder (PDD). It is characterized by difficulties in social interaction; problems with verbal and nonverbal communication; and
patterns of repetitive behaviors coupled with a narrow range of interests—all beginning before the child is three years old. Autism is considered a spectrum disorder, because children diagnosed with it vary widely in the severity of their symptoms; some may be only mildly affected and eventually live independently, while others suffer from severe mental retardation and require lifelong care.
Though defined as a disorder for less than a century, autism has certainly existed for a much longer period of time. The term autism itself appears to have been coined independently by Hans Asperger (1906–1980), an Austrian pediatrician who first used it in a German-language medical journal in 1938, and Leo Kanner (1894–1981), an Austrian psychiatrist who had moved to the United States and published a paper on what he called infantile autism in 1943. Since the 1940s, the definition has expanded to include children who might have simply been described as odd or strange in the 1960s, as well as children who are severely disabled by the disorder.
With regard to social interaction, children with autism are commonly described as loners who are unaware of other people's feelings. They may not respond to their names or make eye contact, and they dislike being held or cuddled. In terms of behaviors, autistic children prefer sameness and are upset by change. They may make repetitive gestures like flapping their hands, spinning, or rocking back and forth. They are often unusually sensitive to lights, noises, or touch, but at the same time they may be completely unaware of danger. Many autistic children seem to be insensitive to pain and do not tell their parents when they are hurt or sick.
Language skills are the third major area in which autistic children are different from others. They often start talking later than other children and may speak in a mechanical, sing-song, or robot-like voice. A child with autism may repeat someone else's words or sentences but may not know how to form a sentence of their own. He or she may have trouble asking
for something in words, using gestures or pointing instead. In some cases children with autism do not refer to themselves as “I” or “me,” but use their names instead.
There has been considerable controversy in recent years because the rate of autism in the United States appears to be rising fairly rapidly. For many years, doctors estimated that autism affected only four or five children in every 10,000. When the Centers for Disease Control and Prevention (CDC) released a report in February 2007 stating that the rate of autism among American children had increased to one in 150 (and one in every 94 boys), many people were quite upset. Although the CDC acknowledges that some of the increase is due to changes in the definition and classification of autistic spectrum disorders or ASDs, some is likely to represent a true increase in the number of affected children. Autism is presently the second most common developmental disability in the United States after mental retardation. The CDC estimates that there are about 560,000 persons in the United States between the ages of one and twenty-one years who have an ASD.
Boys are more likely than girls to have autism; the male/female ratio in the United States is four to one. The reason for the gender difference is not known. Autism is thought to be equally common in all racial and ethnic groups in the United States.
Red Flags for Autism
Although not every child who might be autistic will have all the following characteristics, the American Academy of Pediatrics (AAP) drew up a list in 2004 of “red flags” for parents to watch for:
- The child does not speak as well as others of the same age.
- The child's eye contact is poor.
- The child seems to be in his or her own world.
- The child ignores or “tunes out” other people.
- The child does not smile in return when smiled at.
- The child seems unable to communicate what he or she wants, and either leads the parent to the object or gets it him- or herself.
- The child has trouble following simple directions.
- The child does not show the parent things that he or she finds interesting.
- The child has unusually long and severe temper tantrums.
- The child prefers to play alone.
- The child (if older than two) does not pretend or play make-believe.
- The child is unusually attached to mechanical gadgets or hard objects like key chains rather than to cuddly items like blankets or stuffed toys.
The Autism Society of America estimates that the lifetime cost of caring for an autistic person ranges from $3.5 to $5 million, and that autism costs the United States an average of $90 billion each year (including special education, housing, and transportation services as well as direct health care costs).
The causes of autism are not well understood. In the 1950s many psychiatrists thought that autism was caused by cold or distant parenting—“refrigerator mothers” was a common term—and blamed parents for the disorder. This theory has been disproved by careful studies of families with autistic children. In the 1990s some people theorized that autism is caused by childhood immunizations, particularly the measles-mumps-rubella or MMR vaccine. In 2007, however, a report published in the New England Journal of Medicine showed that vaccines do not cause autism; it is simply that the early symptoms of autism often appear at the age when children are given the MMR vaccine.
- Other possible causes of autism that are still being investigated include:
- Genetic factors. It is known that parents of an autistic child have an increased risk (one chance in twenty) of having a second child with the disorder. No specific gene or genes associated with autism has been identified, however.
- Viruses or other disease agents. Women who have rubella during pregnancy have an increased risk of having an autistic child.
- Father's age. One study showed that fathers over forty when their child was born are six times as likely to have an autistic child as fathers who were thirty or younger. The mother's age doesn't seem to make a difference.
- Difficult pregnancy or childbirth. Some doctors think that damage to a baby's brain before or during birth may play a role in autism.
- Exposure to pesticides and other toxic chemicals. There is some evidence from two studies done in California in 2007 that women exposed to certain pesticides during the first three months of pregnancy have an increased risk of having autistic children.
Common symptoms of autism have already been described; others are listed in the sidebar. Conditions that are often found in children with autism include:
- Mental retardation. About 75 percent of children with autism are mentally retarded, which complicates diagnosis of the disorder.
- Self-injury or aggressive behaviors toward others.
- A loss of previously attained language or social skills. The child appears to develop normally until about fourteen months of age and then starts losing his or her ability to talk and interact with others.
The diagnosis of autism is complex; there is no single diagnostic test for the disorder. In many cases the parents start noticing problems in the child's speech and interactions with them when the child is between fourteen and eighteen months old. The diagnosis may not be made, however, until the child is two to three years of age because of the number of evaluations that may be needed. It usually takes a team of experts in child development to make the diagnosis, including a psychiatrist, a neurologist, a speech therapist, and a pediatrician, all of whom should have specific experience in evaluating and treating children with autism. There are several checklists and screeners for symptoms of autism that these health care professionals may use. In addition, they may order imaging studies, a hearing test, or (in a few cases) a blood test to rule out other possible causes of the child's behaviors.
Even though the diagnosis of autism can be complicated, it is important for parents to have their child evaluated as soon as they notice indications that the child may be autistic. The reason for early evaluation is that it improves the child's chances of making good progress in therapy. Studies have shown that children who begin treatment at or before age three do better than those diagnosed and treated later.
There is no cure for autism. Treatment usually involves several different types of therapy. An important form of therapy is behavior and communication therapy, which is aimed at improving the child's ability to control problem behaviors and to interact with others. In some cases the parents are taught new ways of interacting with their child while he or she is still a toddler. After the child enters school, highly structured education programs have been shown to increase the child's social as well as communication skills.
Medications may be prescribed to treat seizures, depression, anxiety, and other behavioral problems that the child may have.
Because autism is a disorder that places heavy emotional as well as financial burdens on other members of the family, many families with autistic children benefit from family therapy or joining a support group.
The prognosis of autism depends largely on the child's intelligence level and symptom severity. Some autistic children with above-average intelligence and relatively mild symptoms have successfully completed college, married, and started families; severely retarded autistic children, however, may require lifelong care at home or in an institution. Autistic children who start losing previously acquired language skills before age three are at increased risk of seizures as they grow older.
There is no known way to prevent autism.
Researchers are looking in a number of different directions for new treatments for autism and improved diagnostic techniques. Some are studying serotonin, a chemical in the brain that affects the transmission of impulses from one cell to another, to see whether the high levels of this chemical in the blood of some children with autism are related to the disorder in some way. Other scientists are continuing to look for genes that may be linked to autism. In terms of behavior, researchers are testing the effectiveness of a program that combines parent training and medication to reduce the aggressive or disruptive behavior of some children with autism.
WORDS TO KNOW
Neurologist: A doctor who specializes in diagnosing and treating disorders of the nervous system.
Spectrum disorder: A disorder whose symptoms vary in severity from one patient to the next.
SEE ALSO Asperger syndrome; Rubella; Seizure disorder
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"Unknown: Autism." UXL Encyclopedia of Diseases and Disorders. . Encyclopedia.com. (November 18, 2018). https://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/unknown-autism
"Unknown: Autism." UXL Encyclopedia of Diseases and Disorders. . Retrieved November 18, 2018 from Encyclopedia.com: https://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/unknown-autism