A pervasive developmental disorder, autism affects information processing in multiple ways. Many people with autism have difficulties with social interaction and communication, sensory deficits, and poor motor coordination. People with autism often have restricted interests and engage in repetitive behaviors. Because autism's symptoms vary greatly, the condition is said to exist on a spectrum, referred to as Autism Spectrum Disorder. (Asperger's syndrome is a condition that is considered to be "high functioning" autism.) Some people with autism have low intelligence while others are quite intelligent.
Autism usually manifests by age two. It affects far more males than females. The frequency of diagnosis has surged over the past 20 years; it is not clear whether the incidence is truly increasing, whether experts are more alert to it, or whether the diagnosis has shifted to include lesser degrees of impairment. No one knows for sure what causes autism, but numerous studies link it to advanced maternal and/or paternal age at conception, which increases the risk of direct genetic mutations or factors that influence the expression of genes in the developing brain.
Some research suggests that autism reflects an "extreme male brain," because people with the condition often have in extreme form a number of traits associated with masculinity, including obsession with details and systematizing, and low empathic ability. Reports implicating mercury-containing vaccines have proved baseless, although there is some evidence that environmental toxins may play a role. There is no cure for autism, but some symptoms may ease over the years.
Symptoms of Autism
The condition manifests before age three and can be particularly baffling and frustrating because some affected children appear to develop normally until the onset of the disorder. While the severity of symptoms varies greatly, there are invariably impairments of social interaction and communication ability (many autistic children do not talk at all and remain mute throughout life), restriction of interests, and presence of repetitive behaviors. Parents may notice an avoidance of eye contact and lack of responsiveness in young infants, who have difficulty forming emotional bonds and parental attachment. Autistic children also exhibit many kinds of repetitive behaviors early in life, such as hand flapping, body rocking, and making sounds. They may arrange or stack objects over and over again. They show an early preference for unvarying routines of everyday life. Many children inflict injury to themselves by repeated actions such as hand biting and head banging. A majority of autistic children have deficits in motor coordination and have poor muscle tone. They also have unusual responses to sensory experiences and may be highly sensitive to certain sounds, textures, tastes, or smells.
Causes of Autism
No one knows what causes autism. The number of children diagnosed with the disorder has increased significantly over the past decade or so, but experts are not sure whether that reflects an improvement in diagnostic awareness or a true increase in prevalence. Recent evidence suggests that the disorder may be caused by random genetic mutations, as it is associated with advanced maternal and/or paternal age at conception. That would account for the great variability of impairment and neural systems involved.
There is also evidence that the disorder may be caused by failure of embryonic brain cells to undergo normal patterns of migration during early development, affecting later brain structure and wiring of nerve-cell circuits that control social skills, language, movement, and other abilities.
A sex imbalance in the number of affected children (four times more males than females) suggests the disorder may also be related to fetal exposure to abnormally high levels of testosterone in utero; many of the traits of autism are said to reflect male cognitive and behavioral preferences, such as orientation to detail rather than the big picture, affinity for things rather than social experience, facility for math and numbers, and even linguistic impairment; children with autism can accumulate a large vocabulary without being able to sustain a conversation.
A belief that autism is caused by standard childhood immunization with mercury-containing vaccines persists despite many studies discrediting the link and retraction of the original research paper linking autism to immunization.
There is no one specific treatment for autism. Early intervention with highly structured behavioral, cognitive, and communication therapies can sometimes dramatically help children with autism learn skills, but few are able to live independently as adults. School-based educational programs designed for children with autism have been shown to be effective in improving intellectual functioning. Programs that make use of applied behavior analysis (ABA) have become widely accepted as the standard of treatment. In most effective programs, parents are encouraged to be highly involved in their children's care.
While no medication can correct the impairments common to autism, psychoactive drugs including antidepressants, antipsychotics, and anticonvulsants are often prescribed to help control specific symptoms. Anticonvulsant medication may reduce the number of seizures but not eliminate them entirely.
There are many alternative treatments promoted to parents of children with autism, such as facilitated communication and auditory integration training, to name a few; many have been shown to be ineffective. It is important for parents of children with autism to look into prospective treatments as thoroughly as possible.
- Autism and the Male Brain
Taking into account the biological and neurological differences between male and female brains and minds, British psychologist Simon Baron-Cohen proposed the theory that autism represents an extreme version of a typically "male" brain. Men are overall more efficient at systemizing while women are more capable of empathizing. Although there are exceptions, both men and women on the autism spectrum display a strong inclination towards systemizing. They are excellent at visual-spatial manipulation and rule-bound thinking but not as capable of empathy and mind reading. For this reason, Baron-Cohen has labeled autism "mind-blindness."
Baron-Cohen's work may help explain why approximately four times as many males as females are diagnosed on the autism spectrum. Those statistics may not be reliable, however, as females with autism are often misdiagnosed as having other conditions. Baron-Cohen's extreme male brain theory is most likely just the beginning of the story.
The neurodiversity movement arose out of a desire to regard autism as a condition more reflective of positive variation than of pathology. The concept of neurodiversity embraces, celebrates, and respects differences between and among people with autism and other functional but atypical variations in thinking and behavior. Those who support the neurodiversity movement assert there is no one "normal" brain against which all other brains can be measured. Therefore, autism should be broadly accepted and recognized as little more than a natural variation on the human neurological condition. Advocates point out the valuable skills and contributions of different types of minds, just as they highlight the value of other types of diversity. At the same time, some researchers and medical experts believe the concept of neurodiversity can be reasonably applied only to those with high-functioning autism.
- Toward Neuro-Equality
Many people with autism try to improve their social skills and alter their behavior in order to cope more effectively with the neurally typical majority of the population. Others, especially those who exhibit fewer symptoms and need less support, find a strong identity and value in their unusual way of viewing the world and have less desire to conform. In spite of organizational and communication challenges common to those on the autism spectrum, many are highly intelligent and capable of developing new skills and engaging in abstract thinking. For them, neurodiversity supports the promotion of "neuro-equality" in education and employment.
Living with Autism
Everyone on the autism spectrum has a unique experience, but clinicians generally categorize people with autism into three levels depending on the severity of their social deficits and restrictive behaviors. Individuals on the mild end of the spectrum have slight difficulties navigating social interactions and completing certain tasks, while those in the middle of the spectrum have substantial interpersonal challenges and struggle deeply with change. People with a more severe form of autism may have intellectual disability, be unable to speak, or experience extreme discomfort from certain lights, sounds, smells, and textures. They are also at risk of wandering away from their caregivers. Severe autism can lead to aggressive or violent repetitive behaviors such as banging one's head against a wall or striking others. An especially dangerous situation may result in hospitalization; research shows that 11 percent of children with autism have been hospitalized before adulthood. A variety of medical conditions often co-occur with autism, such as epilepsy, anxiety, gastrointestinal issues, or difficulty sleeping.