From Example Problems
Jump to navigation Jump to search

Template:DiseaseDisorder infobox Autism is classified as a neurodevelopmental disorder that manifests itself in markedly abnormal social interaction, communication ability, patterns of interests, and patterns of behavior. Although the specific etiology of autism is unknown, autism most likely results from genetically mediated vulnerability to environmental triggers. And while these environmental factors have not yet been ascertained with scientific certainty, researchers have found at least seven major genes specifically linked to autism. Prevalence in the United States is estimated at one child in 166, but for families that already have one autistic child, incidence is about one in twenty. Diagnosis is based on a list of psychiatric criteria, and a series of standardized clinical tests may also be used.

Physiologically, autism may lack readily visible differences, but it is linked to abnormal biological and neurochemical development of the brain. A complete physical and neurological evaluation will typically be part of determining a diagnosis of autism. Some now speculate that autism is in fact several distinct conditions that manifest themselves in similar ways rather than a single diagnosis.

By definition, autism must manifest delays in "social interaction, language as used in social communication, or symbolic or imaginative play," with "onset prior to age 3 years." (DSM-IV) The ICD-10 also says that symptoms must "manifest before the age of three years." There have been large increases in the reported incidence of autism, for reasons that are heavily debated in the scientific community.

There are cases of children with autism who have improved their social and other skills to the point where they can fully participate in mainstream education and social events, but there are lingering concerns that an absolute cure from autism is impossible with current technology since it involves aspects of neurological brain structure determined very early in development. However, many autistic children and adults who are able to communicate (at least in writing) are opposed to attempts to cure their conditions, and see them as part of who they are.


File:Asperger kl2.jpg
Dr. Hans Asperger described a form of autism in the 1940s that later became known as Asperger's syndrome.

The word autism was first used in the English language by Swiss psychiatrist Eugene Bleuler in a 1912 number of the American Journal of Insanity. The Oxford English Dictionary states that the word is derived from the Greek αυτος (autos, "self"). When referring to a person with autism the term autistic is often used, although the term person with autism may be used instead.

However, the classification of autism did not occur until the middle of the twentieth century, when in 1943, Dr. Leo Kanner of the Johns Hopkins Hospital studied a group of 11 children and introduced the label early infantile autism. At the same time an Austrian scientist, Dr. Hans Asperger, described a different form of autism that became known as Asperger's syndrome—but the widespread recognition of Asperger's work was delayed by World War II in Germany, in fact the majority of his work wasn't officially recognised until 1997.

Thus these two conditions were described and are today listed in the Diagnostic and Statistical Manual of Mental Disorders DSM-IV-TR (fourth edition, text revision 1) as two of the five pervasive developmental disorders (PDD), more often referred to today as autism spectrum disorders (ASD). All of these conditions are characterized by varying degrees of difference in communication skills, social interactions, and restricted, repetitive and stereotyped patterns of behavior.

Very few clinicians today solely use the DSM-IV criteria for determining a diagnosis of autism, which are based on the absence or delay of certain developmental milestones. Many clinicians instead use an alternate means (or a combination thereof) to more accurately determine a diagnosis.


File:Kanner kl2.jpg
Dr. Leo Kanner introduced the label early infantile autism in 1943.

There is a great diversity in the skills and behaviors of individuals diagnosed as autistic, and physicians will often arrive at different conclusions about the appropriate diagnosis. Much of this is due to the sensory system of an autistic which is quite different from the sensory system of other people, since certain stimulations can affect an autistic differently than a non-autistic, and the degree to which the sensory system is affected varies wildly from one autistic person to another.

Nevertheless, professionals within pediatric care and development often look for early indicators of autism in order to initiate treatment as early as possible. However, some people do not believe in treatment for autism, either because they do not believe autism is a disorder or because they believe treatment can do more harm than good.

Social development

Typically, developing infants are social beings—early in life they do such things as gaze at people, turn toward voices, grasp a finger, and even smile. In contrast, most autistic children prefer objects to faces and seem to have tremendous difficulty learning to engage in the give-and-take of everyday human interaction. Even in the first few months of life, many seem indifferent to other people because they avoid eye contact and do not interact with them as often as unautistic children.

Autistic children often appear to prefer being alone rather than in the company of others and may passively accept such things as hugs and cuddling without reciprocating, or resist attention altogether. Later, they seldom seek comfort from others or respond to parents' displays of anger or affection in a typical way. Research has suggested that although autistic children are attached to their parents, their expression of this attachment is unusual and difficult to interpret. Parents who looked forward to the joys of cuddling, teaching, and playing with their child may feel crushed by this lack of expected attachment behavior.

Autistic children appear to lack "theory of mind", the ability to see things from another person's perspective, a behavior cited as exclusive to human beings above the age of five and, possibly, other higher primates such as adult gorillas, chimpanzees and bonobos. Typical 5-year-olds can develop insights into other people's different knowledge, feelings, and intentions, interpretations based upon social cues (e.g., gestures, facial expressions). An individual with autism seems to lack these interpretation skills, an inability that leaves them unable to predict or understand other people's actions. The social alienation of autistic and Asperger's people is so intense from childhood that many of them have imaginary friends as companionship. However, having an imaginary friend is not necessarily a sign of autism and also occurs in non-autistic children.

Although not universal, it is common for autistic people to not regulate their behavior. This can take the form of crying or verbal outbursts that may seem out of proportion to the situation. Individuals with autism generally prefer consistent routines and environments; they may react negatively to them being changed. It is not uncommon for individuals to exhibit aggression, increased levels of self-stimulatory behavior, self-injury or extensive withdrawal in overwhelming situations.

Sensory system

A key indicator to clinicians making a proper assessment for autism would include looking for symptoms much like those found in sensory integration dysfunction. Children will exhibit problems coping with the normal sensory input. Indicators of this disorder include oversensitivity or underreactivity to touch, movement, sights, or sounds; physical clumsiness or carelessness; poor body awareness; a tendency to be easily distracted; impulsive physical or verbal behaviour; an activity level that is unusually high or low; not unwinding or calming oneself; difficulty learning new movements; difficulty in making transitions from one situation to another; social and/or emotional problems; delays in speech, language or motor skills; specific learning difficulties/delays in academic achievement.

One common example is an autistic's hearing. The autistic may have trouble hearing certain people while other people are louder than usual. Or the autistic may be unable to filter out sounds in certain situations, such as in a large crowd of people (see cocktail party effect). However, this is perhaps the part of the autism that tends to vary the most from person to person, so these examples may not apply to every autistic.

Communication difficulties

By age 3, typical children have passed predictable language learning milestones; one of the earliest is babbling. By the first birthday, a typical toddler says words, turns when he or she hears his or her name, points when he or she wants a toy, and when offered something distasteful, makes it clear that the answer is "no." Speech development in autistics takes different paths. Some autistics remain mute throughout their lives while being fully literate and able to communicate in other ways—images, sign language, and typing are far more natural to them. Some infants who later show signs of autism coo and babble during the first few months of life, but stop soon afterwards. Others may be delayed, developing language as late as the teenage years. Still, inability to speak does not mean that autistics are unintelligent or unaware. Once given appropriate accommodations, many will happily converse for hours, and can often be found in online chat rooms, discussion boards or websites and even using communication devices at autism-community social events such as Autreat.

Those who do speak often use language in unusual ways, retaining features of earlier stages of language development for long periods or throughout their lives. Some speak only single words, while others repeat the same phrase over and over. Some repeat what they hear, a condition called echolalia. Sing-song repetitions in particular are a calming, joyous activity that many autistic adults engage in. Many autistics have a strong tonal sense, and can often understand spoken language better if it is sung to them.

Some children may exhibit only slight delays in language, or even seem to have precocious language and unusually large vocabularies, but have great difficulty in sustaining typical conversations. The "give and take" of non-autistic conversation is hard for them, although they often carry on a monologue on a favorite subject, giving no one else an opportunity to comment. When given the chance to converse with other autistics, they comfortably do so in "parallel monologue"—taking turns expressing views and information. Just as non-autistics have trouble understanding autistic body languages, vocal tones, or phraseology, autistics similarly have trouble with such things in non-autistics. In particular, autistic language abilities tend to be highly literal; non-autistics often inappropriately attribute hidden meaning to what autistics say or expect the autistic to sense such unstated meaning in their own words.

The body language of autistics can be difficult for non-autistics to understand. Facial expressions, movements, and gestures may be easily understood by some other autistics, but do not match those used by non-autistics. Also, their tone of voice has a much more subtle inflection in reflecting their feelings, and the non-autistic's auditory system often cannot sense the fluctuations. What seems to non-autistic people like a high-pitched, sing-song, or flat, robot-like voice is common in autistic children. Some autistic children with relatively good language skills speak like little adults, rather than communicating at their current age level, which is one of the things that can lead to problems.

Since non-autistics are often unfamiliar with the autistic body language, and since autistic natural language may not tend towards speech, autistic people often struggle to let non-autistics know what they need. As anybody might do in such a situation, they may scream in frustration or resort to grabbing what they want. While waiting for non-autistic people to learn to communicate with them, autistics do whatever they can to get through to them. Communication difficulties may contribute to autistic people becoming socially anxious or depressed.

Repetitive behaviors

Although autistics usually appear physically normal and have good muscle control, unusual repetitive motions, known as self-stimulation or "stimming," may set them apart. These behaviors might be extreme and highly apparent or more subtle. Some children and older individuals spend a lot of time repeatedly flapping their arms or wiggling their toes, others suddenly freeze in position. As children, they might spend hours lining up their cars and trains in a certain way, not using them for pretend play. If someone accidentally moves one of these toys, the child may be tremendously upset. Autistic children often need, and demand, absolute consistency in their environment. A slight change in any routine—in mealtimes, dressing, taking a bath, or going to school at a certain time and by the same route—can be extremely disturbing. Autistics sometimes have a persistent, intense preoccupation. For example, the child might be obsessed with learning all about vacuum cleaners, train schedules or lighthouses. Often they show great interest in numbers, symbols or science topics.

DSM definition

Autism is defined in section 299.00 of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) as:

  1. A total of six (or more) items from (1), (2) and (3), with at least two from (1), and one each from (2) and (3):
    1. qualitative impairment in social interaction, as manifested by at least two of the following:
      1. marked impairment in the use of multiple nonverbal behaviors such as eye-to-eye gaze, facial expression, body postures, and gestures to regulate social interaction
      2. failure to develop peer relationships appropriate to developmental level
      3. a lack of spontaneous seeking to share enjoyment, interests, or achievements with other people (e.g., by a lack of showing, bringing, or pointing out objects of interest)
      4. lack of social or emotional reciprocity
    2. qualitative impairments in communication as manifested by at least one of the following:
      1. delay in, or total lack of, the development of spoken language (not accompanied by an attempt to compensate through alternative modes of communication such as gesture or mime)
      2. in individuals with adequate speech, marked impairment in the ability to initiate or sustain a conversation with others
      3. stereotyped and repetitive use of language or idiosyncratic language
      4. lack of varied, spontaneous make-believe play or social imitative play appropriate to developmental level
    3. restricted repetitive and stereotyped patterns of behavior, interests, and activities, as manifested by at least one of the following:
      1. encompassing preoccupation with one or more stereotyped and restricted patterns of interest that is abnormal either in intensity or focus
      2. apparently inflexible adherence to specific, nonfunctional routines or rituals
      3. stereotyped and repetitive motor mannerisms (e.g., hand or finger flapping or twisting, or complex whole-body movements)
      4. persistent preoccupation with parts of objects
  2. Delays or abnormal functioning in at least one of the following areas, with onset prior to age 3 years: (1) social interaction, (2) language as used in social communication, or (3) symbolic or imaginative play.
  3. The disturbance is not better accounted for by Rett's Disorder or Childhood Disintegrative Disorder.

The Diagnostic and Statistical Manual's diagnostic criteria in general is controversial for being vague and subjective. (See the DSM cautionary statement.) The criteria for autism is much more controversial and some clinicians today may ignore it completely, instead solely relying on other methods for determining the diagnosis.

Types of autism

Autism presents in a wide degree, from those who are nearly dysfunctional and apparently mentally handicapped to those whose symptoms are mild or remedied enough to appear unexceptional ("normal") to the general public. In terms of both classification and therapy, autistic individuals are often divided into those with an IQ<80 referred to as having "low-functioning autism" (LFA), while those with IQ>80 are referred to as having "high-functioning autism" (HFA). Low and high functioning are more generally applied to how well an individual can accomplish activities of daily living, rather than to IQ. The terms low and high functioning are controversial and not all autistics accept these labels.

This discrepancy can lead to confusion among service providers who equate IQ with functioning and may refuse to serve high-IQ autistic people who are severely compromised in their ability to perform daily living tasks, or may fail to recognize the intellectual potential of many autistic people who are considered LFA. For example, some professionals refuse to recognize autistics who can speak or write as being autistic at all, because they still think of autism as a communication disorder so severe that no speech or writing is possible.

As a consequence, many "high-functioning" autistic persons, and autistic people with a relatively high IQ, are underdiagnosed, thus making the claim that "autism implies retardation" self-fulfilling. The number of people diagnosed with LFA is not rising quite as sharply as HFA, indicating that at least part of the explanation for the apparent rise is probably better diagnostics.

Asperger's and Kanner's syndrome

File:Hans Asperger.jpg
Asperger described his patients as "little professors".

In the current Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR), the most significant difference between Autistic Disorder (Kanner's) and Asperger's syndrome is that a diagnosis of the former includes the observation of "[d]elays or abnormal functioning in at least one of the following areas, with onset prior to age 3 years: (1) social interaction, (2) language as used in social communication, or (3) symbolic or imaginative play[,]" [1] while a diagnosis of Asperger's syndrome observes "no clinically significant delay" in these areas. [2]

The DSM makes no mention of level of intellectual functioning, but the fact that Asperger's autistics as a group tend to perform better than those with Kanner's autism has produced a popular conception that Asperger's syndrome is synonymous with "higher-functioning autism," or that it is a lesser disorder than autism. There is also a popular but not necessarily true conception that all autistic individuals with a high level of intellectual functioning have Asperger's autism or that both types are merely geeks with a medical label attached. Also, autism has evolved in the public understanding, but the popular identification of autism with relatively severe cases as accurately depicted in Rain Man has encouraged relatives of family members diagnosed in the autistic spectrum to speak of their loved ones as having Asperger's syndrome rather than autism.

Autism as a spectrum disorder

For more details on this topic, see Autistic spectrum.

Another view of these disorders is that they are on a continuum known as autistic spectrum disorders. A related continuum is Sensory Integration Dysfunction, which is about how well we integrate the information we receive from our senses. Autism, Asperger's syndrome, and Sensory Integration Dysfunction are all closely related and overlap.

There are two main manifestations of classical autism, regressive autism and early infantile autism. Early infantile autism is present at birth while regressive autism begins before the age of 3 and often around 18 months. Although this causes some controversy over when the neurological differences involved in autism truly begin, some believe that it is only a matter of when an environmental toxin triggers the disorder. This triggering could occur during gestation due to a toxin that enters the mother's body and is transfered to the fetus. The triggering could also occur after birth during the crucial early nervous system development of the child due to a toxin directly entering the child's body.


Similar to the causes and origins of autism and Asperger's syndrome, the model of what autism really is brings its own continuing conjecture and debate. Amongst several competing theories are the underconnectivity theory[3] developed by cognitive scientists at Carnegie Mellon University and the University of Pittsburgh, the Neanderthal theory[4], Simon Baron-Cohen's extreme male brain theory, the lack of theory of mind, and the preoperational-autism theory.

  • The extreme male brain theory

The extreme male brain theory of autism, proposed by Simon Baron-Cohen in accordance with his empathizing-systemizing theory[5], suggests that autistics have extreme forms of what he describes as the male brain: they are good (often very good) at systemizing, and very bad at empathizing. Poetry composed by autistics[6] would seem to challenge this idea, but the scientific validity of the idea is still under discussion.

  • The preoperational-autism theory

The preoperational-autism theory states that autistic people are those who become neurologically impeded at the preoperational stage of cognitive development, where much of information processing is at a holistic-visual level and largely musical and nonverbal. This also addresses the issue of the theory of mind where children (autistic and non-autistic) at the preoperational stage of cognitive development have not attained decentralization from egocentrism.

  • Monotropism

In this model of mind, mental events compete for and consume attention. In a polytropic mind, many interests have a moderate amount of attention put into them, while in a monotropic mind, the person's attention is put into a few more specialized interests. The theory argues that when many interests are aroused, multiple complex behaviors emerge, but if only a few interests are aroused, fewer—but more intense—behaviors emerge. A May 2005 article in The Autism Journal [7] and information available from the group Autism and Computing[8] delves further into this subject.

  • Underconnectivity theory

Underconnectivity theory theorizes that autism is a system-wide brain disorder that limits the coordination and integration among brain areas. With the aid of fMRI, it was seen that white matter, which connects various areas of the brain like cables, has abnormalities in people with autism. This theory may be related to the "lack of central coherence" theory proposed by Uta Frith, which suggests that children with autism are good at paying attention to detail but have difficulty integrating information from a range of sources.

  • Mind blindness theory

This theory says that the autistic person has "mind blindness", or the inability to create models of other people's thoughts. The typical example of this is the Sally-Anne test where the subjects have to try to determine what a third party's action will be (see theory of mind also). Some autistics do not seem to fit this model, however.

  • Faulty mirror neuron theory

In some instances, brain areas that are active during the observation of hand-movements are silent in autistic individuals [9]. The activity is markedly enhanced in non-autistic persons. So the social deficits observed in autism could be the result of a faulty mirror neuron system, which could also prevent normal development of empathy.

  • Social construct theory

This is the belief that autism is not really a disorder, but instead is a social construct. That is, supporters of this theory do not believe autism exists at all; they believe (partly supported by recent reference to the rising cases of diagnosed autism) that autism is just the way some people are—that is, a part of the person's personality, which might explain the apparent difficulty in finding a model and a cure. This is further supported by the fact that autistic people have normal lifespans and their condition often comes with advantages, not just disadvantages.

  • Genetics theory

Research done by some institutions seek to find a way for early and more accurate detection of autism similar to Rett syndrome. Instead of searching for one particular gene as the cause for autism, many of the studies tend to search for complex interactions between a number of genes.

A 2005 study done by the Duke Center for Human Genetics at Duke University finds some evidence that complex interactions between GABA (gamma aminobutyric acid) receptor genes might be part of the cause of autism. One of the functions of the GABA genes is to inhibit the nerve system from firing. The theory is that somehow GABA genes suffer damage of some kind, leading to an overwhelmed sensory system causing the characteristics or symptoms of autism.[10],[11]


While the epidemiology of autism is largely unknown, there is no shortage of theories in the area. In addition, in recent times the number of diagnosed incidents of autism has risen dramatically.

Theories of the etiology of autism

  • Brain testosterone theory

Simon Baron-Cohen proposes a model for autism based in his empathising-systemising (E-S) theory[12]. His team at the Autism Research Centre in Cambridge, UK, measured testosterone levels in the amniotic fluid of mothers while pregnant. This is presumed to reflect levels in the babies themselves. The team found that the babies with higher fetal testosterone levels had a smaller vocabulary and made eye contact less often when they were a year old.

His group has looked at the original 58 children again, at age four. The researchers found that the children with higher testosterone in the womb are less developed socially, and the interests of boys are more restricted than girls. The results are published in the Journal of Child Psychology and Psychiatry in a 2004 issue [13].

Baron-Cohen theorizes that high fetal testosterone levels push brain development towards an improved ability to see patterns and analyze systems. Males supposedly tend to be better at these tasks than females. But the high levels are thought to inhibit the development of communication and empathy, which are allegedly typical female skills. (New Scientist, 24 May 2003) [14].

However, there is still no demonstrable evidence that testosterone levels affect brain development or autism. Gender or biodeterminism is a fashionable explanation for many human behaviors, but has been challenged by other professionals[15].

  • Vaccine theory

Controversial research by Andrew Wakefield in the UK that was published in The Lancet in the February 1998 issue, dubbed the "Wakefield Study", suggested a possible link between autism and the MMR vaccine. The original research has come under criticism, largely due to an alleged conflict of interest on Wakefield's part [16], rather than the reliability of the study results.

Critics have claimed that Wakefield's study contains many obvious flaws, including an inability to recognize bias in his sample, and 12 of the original 14 authors of the paper retracted a controversial conclusion of the study, that further research into possible triggers, such as MMR, should be undertaken. The co-authors did not retract Wakefield's discovery of autistic enterocolitis as a completely new syndrome, which has now been replicated in studies around the world as a new, unexplained disease in patients with autism. In October, 2005, a study by the respected Cochrane Library said, on the basis of 31 pieces of research into the possible side effects of MMR, that it found no association between MMR and autism. It also said that no fewer than nine of the most celebrated studies used against him were unreliable in the way they were constructed, add that their conclusion MMR was 'safe' or 'well-tolerated' needs to be 'interpreted with caution'.[17] Controversy continues, with Wakefield continuing to defend his theory.

Although allegations that Wakefield study is flawed does not in itself prove that no autism-vaccine connection exists, his critiics vigorously suggest that the theory may be false. Several independent groups, including the National Academy of Sciences, have conducted thorough investigations into the possible link and concluded that the evidence does not support a link between the MMR vaccine and autism.

One study by Gillberg and Heijbel in 1998 examining the prevalence of autism in children born in Sweden from 1975 to 1984[18] found no difference in the prevalence of autistic children born before the introduction of the MMR vaccine in Sweden and those born after the vaccine was introduced. Another study, conducted by Madsen and other researchers in 2002, studied all children born in Denmark from January 1991 through December 1998[19]. There were a total of 537,303 children in the study; 440,655 of the children were vaccinated with MMR and 96,648 were not. The researchers did not find a higher risk of autism in the vaccinated than in the unvaccinated group of children.

Research in the U.S. has suggested a similar link between autism and the DPT vaccine. However, unlike early claims from Wakefield, it is doubtful that a large majority of autism cases would come from this vaccine. Despite all the evidence to the contrary, controversy surrounding autism and vaccines continues to this day, and many polls, such as the autism coach poll[20], which involved only 15 respondents, show vaccines as the most popular theory currently on the etiology of autism among parents of autistic children.

In a controversial article in June 2005, Robert F. Kennedy, Jr. described research suggesting that it is not the vaccines themselves, but a mercury-based preservative called thimerosal, used in some vaccine preparations (although not MMR), that may be a cause of autism[21]. Kennedy argues that autism was first observed in children who were born around the time of introduction of thimerosal into mass-produced vaccines, and that the incidence of autism in the United States is well correlated with the amounts of thimerosal children receive during their first two years of life. However, the CDC has described a link between thimerosal and autism as 'unlikely'.[22]

In 1999 the Public Health Service (including the CDC, FDA, and NIH) recommended that thimerosal no longer be used in vaccine preparations. And while thimerosal is now utilized in only a very few childhood vaccines, it has not been established that autism rates have dropped significantly. The CDC and most medical organizations have gone to great lengths to discredit this theory of autism. However, the California Department of Developmental Services (DDS), considered to have the best reporting system for autism in the US,[23] released in late 2005 indicating an unprecedented decline in new cases of professionally diagnosed, full syndrome DSM IV autism entering the DDS system, from 734 new cases during the second quarter of 2005 to 678 new cases during the third quarter of 2005, a 7 1/2% decline in one quarter. The modest, but statistically significant decline coincides with vaccines containing thimerosal being phased out in recent years.

  • Brain trauma

Susan Bryson has claimed that some autistics have evidence of trauma to the brain stem in early development, and that a small portion of the thalidomide victims have become autistic. The victims' limbs were normal unless thalidomide use continued later in the pregnancy. The brain stem anomaly's most striking feature is inability to focus attention away from a stimulus in a short time like neurotypicals, as demonstrated in a psychological test.

Some people claim the inability to shift attention quickly interferes with the ability to read nonverbal language where fast attention shifts are needed (such as eye language), suggesting that being nonverbal is not a primary feature of autism. Strong and shiftless focus is, however, a benefit in some areas like science, programming, and advanced mathematics. This is supported by the monotropism hypothesis.

Dr. Bernard Rimland's influential research and his book Infantile Autism (1967) argued that autism was not caused by childhood trauma or abuse, but by damage to certain areas of the brain, particularly the reticular formation which associates present sensory input with memories of past experiences. Dr. Rimland is a foremost advocate of the theory that autism may be precipitated by mercury and heavy metal toxicity[24]. He also is prominent in increasingly common claims of successful treatment of autism in children—particularly regarding improvements in ability to comprehend the spoken word—with the gluten-free, casein-free diet and mercury chelation therapy.

Others claim Dr. Bernard Rimland's methods alleviate the symptoms of heavy metal poisoning, but not autism. Curing heavy metal poisoning when it is present is a worthy goal (it helps with IQ and other learning difficulties as well as general health), but claiming a benefit for autism is a misrepresentation. Heavy metal poisoning may be more common among autistics due to a severe metallothionein deficiency, but more evidence is needed to substantiate the idea that heavy metals cause autism. It is still being studied. The presence of heavy metals, particularly mercury, might make an autism diagnosis more likely, however.

  • Viral or bacterial infection

A growing body of peer-reviewed studies published in mainstream journals has shown that many common diseases of previously unknown origin are caused by the presence of slowly acting viruses. For example, cervical cancer is caused by the human papilloma wart virus; some cases of liver cancer are caused by hepatitis C or B; Schizophrenia may be caused by Borna virus. Paul W. Ewald, among others, argues that the available data on the origin of autism is consistent with it being caused by a virus or infection.

Increase in diagnoses of autism

For more details on this topic, see Autism epidemic.
The number of reported cases of autism has increased dramatically over the past decade. Statistics in graph from the National Center for Health Statistics.

There has been an explosion worldwide in reported cases of autism over the last ten years, which is largely reminiscent of increases in the diagnosis of schizophrenia and multiple personality disorder in the twentieth century. This has brought rise to a number of different theories as to the nature of the sudden increase.

Epidemiologists argue that the rise in diagnoses in the United States is partly or entirely attributable to changes in diagnostic criteria, reclassifications, public awareness, and the incentive to receive federally mandated services. A widely cited study from the M.I.N.D. Institute in California (17 October 2002), claimed that the increase in autism is real, even after those complicating factors are accounted for (see reference in this section below).

Other researchers remain unconvinced (see references below), including Dr. Chris Johnson, a professor of pediatrics at the University of Texas Health Sciences Center at San Antonio and cochair of the American Academy of Pediatrics Autism Expert Panel, who says, "There is a chance we're seeing a true rise, but right now I don't think anybody can answer that question for sure." (Newsweek reference below).

The answer to this question has significant ramifications on the direction of research, since a real increase would focus more attention (and research funding) on the search for environmental factors, while little or no real increase would focus more attention to genetics. On the other hand, it is conceivable that certain environmental factors (vaccination, diet, societal changes) may have a particular impact on people with a specific genetic constitution. There is little public research on the effects of in vitro fertilization on the number of incidences of autism.

One of the more popular theories is that there is a connection between "geekdom" and autism. This is hinted, for instance, by a Wired Magazine article in 2001 entitled "The Geek Syndrome", which is a point argued by many in the autism rights movement[25]. This article, many professionals assert, is just one example of the media's application of mental disease labels to what is actually variant normal behavior—they argue that shyness, lack of athletic ability or social skills, and intellectual interests, even when they seem unusual to others, are not in themselves signs of autism or Asperger's syndrome. See clinomorphism for further discussion of this issue.

Due to the recent publicity surrounding autism and autistic spectrum disorders, an increasing number of independent adults are choosing to seek diagnoses of high-functioning autism or Asperger's syndrome in light of symptoms they currently experience or experienced during childhood. Since the cause of autism is thought to be at least partly genetic, a proportion of these adults seek their own diagnosis specifically as follow-up to their children's diagnoses. Because autism falls into the pervasive developmental disorder category, strictly speaking, symptoms must have been present in a given patient before age seven in order to make a differential diagnosis.


There are many different therapies and treatments but the success they have varies dramatically from person to person. Remediation of the debilitating aspects of autism is also hindered by widespread disagreement over its nature and causes, and by a lack of recognized and effective therapies.

The behavioral and cognitive functioning of individuals with autism might improve with the help of psychosocial and pharmacological interventions. Among psychosocial treatments, intensive, sustained special education programs and behavior therapy early in life might increase the ability of children with autism to acquire language and the ability to learn. In adults with autism, some studies have found beneficial effects of the antidepressant medications clomipramine and fluoxetine and the antipsychotic medication haloperidol. In many cases quite a few medications will have to be tried until a successful drug is found, and the drug may lose effectiveness later in life, complicating matters further.

Dr. Bruno Bettelheim believed that autism was linked to early childhood trauma, and his work was highly influential for decades. Parents, especially mothers, of autistics were blamed for having caused their child's condition through the withholding of affection. Leo Kanner, who first described autism (Autistic disturbances of affective contact, 1943) originated the "refrigerator mother" hypothesis, which held that autism was at least partly caused by a lack of affection from the mother. Although Kanner eventually renounced the concept and apologized publicly, Bettelheim took the theory further. These theories did nothing to address the fact that having more than one autistic child in a family is exceptional, not the rule. Treatments based on these theories failed to help autistic children.

Applied Behavior Analysis

A major breakthrough (in some respects) in the remediation of autistic behaviors came through work spearheaded by Ole Ivar Lovaas, who believed that success could be obtained by behavioral approaches.

Lovaas' approaches—often referred to as Discrete Trial, Intensive Behavior Intervention, and Applied Behavior Analysis—are some of the best known and most widely used in the field and focus on the development of attention, imitation, receptive or expressive language, and pre-academic and self-help skills. Using a one-to-one therapist-child ratio and the "antecedent-behavior-consequence" (ABC) model, interventions based on this work involve trials or tasks. Each consists of (a) an antecedent, which is a directive or request for the child to perform an action; (b) a behavior, or response from the child, which may be categorized as successful performance, noncompliance, or no response; and (c) a consequence, defined as the reaction from the therapist, which ranges from strong positive reinforcement to a strong negative response, "No!"(Autism Society of America, 2001)[26].

Lovaas' Applied Behavioral Analysis (ABA) methods were the first scientifically validated therapy for autism. Early intervention, generally before school-age, seems to be critical to achieving optimal outcomes.

ABA techniques based on B. F. Skinner's Verbal Behavior have succeeded in helping nonverbal children start to talk, typically going from zero words to several dozen. By allowing children to express their needs, even rudimentary speech can alleviate frustration and tantrums.

The scientific validity of Lovaas's methods is questioned by many professionals as well as parents and autistics themselves. Lovaas's initial studies looked promising but have not been reproduced by others with the same rate of success. There have not been any double-blind studies that validate ABA, so it is unclear if any improvements seen in children are simply due to their normal course of development.

Many also feel that there are serious ethical problems, and point out that early ABA was based around the use of aversives which could be experienced by an autistic person as confusing and painful [27]. Most contemporary behaviorist programs for autistics employ no aversiveness at all, and not all attempt to "extinguish" behaviors such as rocking or spinning that autistics use for calming purposes.

ABA may not be appropriate for every autistic or developmentally delayed child. ABA has come into widespread use only in the last decade and the demand is outstripping the supply of committed and experienced service providers. As a result, parents of children need to be extra vigilant in choosing appropriate treatments for their children and especially in choosing providers, who may be inexperienced, use questionable methods or even deceive parents that they are competent to run an ABA or any other program. Such problems have led to horror stories from some parents. [28] [29]

Relationship Development Intervention

Relationship Development Intervention (RDI) is a research-based treatment program developed by Dr. Steven E. Gutstein. Whereas ABA aims to teach social skills directly, RDI focuses on building the "dynamic intelligence" that underlies the acquisition of those social skills in neurotypical children. It also focuses on the building blocks of motivation by developing episodic memory (seen as impaired in autism) and filling it with the child's own personal stories of competence and mastery. RDI emphasizes declarative (as opposed to imperative) communication, and aims for an appropriate balance of verbal and nonverbal communication.

Dr. Gutstein claims that 70% of his patients improved their ADOS score within 18 months, which is unprecedented (it was previously thought that improvement on the ADOS was impossible), and that a similar proportion are able to enter school without a shadow teacher or other personal assistant.


The Son-Rise program was developed by Samahria & Barry Neil Kaufman, who founded the Option Institute to promulgate their more general philosophy upon which the Son-Rise program is partially based, and to provide training in this treatment approach. It is a home-based program with emphasis on eye contact, accepting the child without judgment, and engaging the child in a noncoercive way. The Association for Science in Autism Treatment (ASAT)[30] maintains a Description of the Son-Rise Program[31].

Autism and computing

Many studies have shown that computers help calm autistic children and help them communicate,[32] and that often autistic children take to computers more quickly than non-autistic people. However, evidence suggesting that computers help autistic children communicate without computers is less promising, and autistic children are not immune to the effects of overuse of computers. One can deduce from this that autistic children often communicate better through e-mail than normal speech, but in rare cases the reverse can be true also.

Some groups have proposed more precise scientific reasons for why this happens. One such group, the nonprofit Autism and Computing[33], claims that autism is monotropism (as stated in an above section), and they argue that computers provide an easy way of joining attention tunnels (a.k.a. undivided attention) with minimal discomfort, circumventing some of the most disabling features of autistic spectrum disorders.

Gluten-free, casein-free diet


Dr. Karl Ludwig Reichelt claims to have found peptides from casein and gluten that worsen the symptoms of autistic children. These peptides are casomorphines and gluten exorphines, which influence the brain. According to Dr. Reichelt, significant improvement has been seen in the symptoms of some of his patients with autism who had been put on a diet that omits these peptides. The diet is called the gluten-free, casein-free diet. Some physicians see diet as a central part of the treatment, but in addition to many other treatments at the same time[34].


Due to the complexity of autism, there are many facets of sociology that need to be considered when discussing it, such as the culture possible with it. In addition, there are several communities being formed within the autistic community, and in recent times they have become a bit polarized.


For more details on this topic, see Autistic community.

Much like many other controversies in the world, the autistic community itself has splintered off into several groups. Essentially, these groups are those who seek a cure for autism, dubbed pro-cure, those who do not desire a cure for autism and as such resist it, dubbed anti-cure, and the many people caught in the middle of the two. In recent history, with scientists learning more about autism and possibly coming closer to a cure, some members of the "anti-cure" movement sent a letter to the United Nations demanding to be treated as a minority group rather than a group with a mental disability or disease. Websites such as present the view of the anti-cure group.

There are numerous resources available for autistics from many groups. Due to the fact that many autistics find it easier to communicate online than in person, many of these resources are available online. In addition, sometimes successful autistic adults in a local community will help out children with autism, much in the way a master would help out an apprentice, for example.

2002 was declared Autism Awareness Year in the United Kingdom—this idea was initiated by Ivan and Charika Corea, parents of an autistic child, Charin. Autism Awareness Year was led by the British Institute of Brain Injured Children, Disabilities Trust, National Autistic Society, Autism London and 800 organizations in the United Kingdom. It had the personal backing of British Prime Minister Tony Blair and parliamentarians of all parties in the Palace of Westminster.


For more details on this topic, see Autistic culture.

With the recent increases in autism rates, an autistic culture has begun to develop. Autistic culture is much akin to deaf culture, which says that autism is a unique way of being and not a disorder to be cured, i.e., "anti-cure". There are some commonalities which are specific to autism in general as a culture, not just "autistic culture".

It is a common misperception that people with autism do not marry; many do get married. Often, it is to another person with autism, although this is not always the case. Many times this is due to shared interests or obsessions, but more often than not it is due to more compatibility with personality types. Multigenerational autistic families have also recently become a bit more common.

Interests with autistic people and so-called "geeks" or "nerds" can often overlap as autistic people can sometimes become preoccupied with certain subjects much like the variant normal behavior geeks experience. However, in practice many autistic people have difficulty with working in groups, which impairs them even in the most "technical" of situations.

Autistic adults

Temple Grandin, one of the more successful adults with autism. Photograph courtesy Joshua Nathaniel Pritikin and William Lawrence Jarrold.

Some autistic adults are able to work successfully in mainstream jobs, usually those with high-functioning autism or Asperger's syndrome. Nevertheless, communication and social programs often cause difficulties in many areas of the autistic's life. Other autistics are capable of employment in sheltered workshops under the supervision of managers trained in working with persons with disabilities. A nurturing environment at home, at school, and later in job training and at work, helps autistic people continue to learn and to develop throughout their lives. Some argue that the internet allows autistic individuals to communicate and form online communities, in addition to being able to find occupations such as independent consulting, which does generally not require much human interaction offline.

In the United States, the public schools' responsibility for providing services ends when the autistic person is in their 20s, depending on each state. The family is then faced with the challenge of finding living arrangements and employment to match the particular needs of their adult child, as well as the programs and facilities that can provide support services to achieve these goals.

Autistic savants

The autistic savant phenomenon is sometimes seen in autistic people. The term is used to describe a person who is autistic and has extreme talent in a certain area of study. Although there is a common association between savants and autism (an association created by the 1988 film Rain Man), most autistic people are not savants. Calendar calculators and fast programming skills are the most common form. The famous example is Daniel Tammet, the subject of the documentary film The Brain Man [35] (Kim Peek, one of the inspirations for Dustin Hoffman's character in the film Rain Man, is not autistic). "Bright Splinters of the Mind" is a book that explores this issue further.

Other pervasive developmental disorders

Autism and Asperger's syndrome are just two of the five pervasive developmental disorders (PDDs). The three other pervasive developmental disorders are Rett syndrome, Childhood disintegrative disorder, and Pervasive developmental disorder not otherwise specified. Some of the these are related to autism, while some of them are entirely seperate conditions.

Rett syndrome

Rett syndrome is relatively rare, affecting almost exclusively females, one out of 10,000 to 15,000. After a period of normal development, sometime between 6 and 18 months, autism-like symptoms begin to appear. The little girl's mental and social development regresses; she no longer responds to her parents and pulls away from any social contact. If she has been talking, she stops; she cannot control her feet; she wrings her hands. Some of these early symptoms may be confused for autism. Some of the problems associated with Rett syndrome can be treated. Physical, occupational, and speech therapy can help with problems of coordination, movement, and speech.

Scientists sponsored by the National Institute of Child Health and Human Development have discovered that a mutation in the sequence of a single gene causes Rett syndrome, and can physically test for it with a 80% accuracy rate [36]. Rett syndrome in the past was sometimes classified as an autistic spectrum disorder, however most scientists agree that Rett syndrome is a developmental disorder and not part of the autistic spectrum [37].

Childhood disintegrative disorder

Childhood disintegrative disorder (CDD, and sometimes abbreviated as CHDD also) is a condition appearing in 3 or 4 year old children who have developed normally until age 2. Over several months, the child will deteriorate in intellectual, social, and language functioning from previously normal behaviour. This long period of normal development before regression helps differentiate CDD from Rett syndrome (and in fact it must be differentiated from autism in testing). The cause for CDD is unknown (thus it may be a spectrum disorder) but current evidence suggests it has something to do with the central nervous system [38] [39].

Pervasive developmental disorder not otherwise specified

Pervasive developmental disorder not otherwise specified, or PDD-NOS, is referred to as a subthreshold condition because it is a classification which is given to someone who suffers from impairments in social interaction, communication, and/or stereotyped behaviour but does not meet the criteria for one of the other four pervasive developmental disorders. Unlike the other four pervasive developmental disorders, PDD-NOS has no specific guidelines for diagnosis, so the person may have a lot of characteristics of an autistic person, or few to none at all. Note that pervasive developmental disorder is not a diagnosis, just a term to refer to the five mentioned conditions, while PDD-NOS is an official diagnosis [40].

See also

  • General
  • Groups
  • Controversy
  • Lists



  1. ^  Template:Web reference
  2. ^  Template:Web reference
  3. ^  Template:Web reference
  4. ^  Template:Web reference
  5. ^  Template:Web reference
  6. ^  Template:Web reference
  7. ^  Template:Journal reference issue Online PDF version from
  8. ^  Template:Web reference
  9. ^  Template:Web reference
  10. ^  Template:Web reference
  11. ^  Template:Journal reference issue (abstract)
  12. ^  Template:Web reference
  13. ^  Template:Journal reference
  14. ^  Template:Journal reference issue
  15. ^  Template:Web reference
  16. ^  Template:Web reference
  17. ^  Template:Journal reference
  18. ^  Template:Journal reference issue
  19. ^  Template:Web reference
  20. ^  Template:Web reference
  21. ^  Template:Web reference
  22. ^  Template:Citenewsauthor
  23. ^  Template:Web reference
  24. ^  Template:Web reference
  25. ^  Template:Web reference
  26. ^  Template:Web reference
  27. ^  Template:Web reference
  28. ^  Template:Web reference
  29. ^  Template:Web reference
  30. ^  Template:Web reference
  31. ^  Template:Web reference
  32. ^  Template:Web reference
  33. ^  Template:Web reference
  34. ^  Template:Web reference
  35. ^  Template:Web reference
  36. ^  Template:Web reference
  37. ^  Template:Web reference

External links

Look up autism in Wiktionary, the free dictionary.
  • General - Autism Spectrum Disorder - 'Teaching Students with Autism', Glen Dunlap, Lise Fox, ERIC Digest (October, 1999)
  • Blogs
About.Com - 'Autism/Pervasive Developmental Disorders', Adelle Jameson Tilton, - 'Autism News and More' - 'Adventures in Autism' - 'Autism Symptoms'
  • Organizations - 'Center for the Study of Autism', Autism Research Institute (founded by Bernard Rimland) - Autism Society of America
  • Resources - 'PARIS: Public Autism Resource & Information Service' (directory of UK autism services) - 'Autism Resources: offering information and links regarding the developmental disabilities autism and Asperger's Syndrome' - 'everything you need to know about autism', Autism Today - 'Focus on Autism' (selection of documentaries, interviews, etc.)

Template:Pervasive developmental disorders

de:Autismus es:Autismo fr:Autisme ia:Autismo it:Autismo he:אוטיזם hu:Autizmus ms:Autisme nl:Autisme ja:自閉症 no:Autisme pl:Autyzm pt:Autismo simple:Autism sr:Аутизам fi:Autismi tr:Otizm zh:自閉症