Autism
Until recently, Autism was classified as an intellectual Impairment.
Today, it is better understood to be a neuro-developmental disorder with overlapping intellectual disbility features, in some instances.
Autism is characterized by impaired social interaction, verbal and non-verbal communication, and restricted and repetitive behavior.
Parents usually notice signs in the first two years of their child’s life.
These signs often develop gradually. Some children with autism reach their developmental milestones at a normal pace and then regress.
Globally, autism is estimated to affect 21.8 million people as of 2013.
It occurs four to five times more often in boys than girls.
While autism is often inherited, researchers suspect both environmental and genetic factors as causes.
In rare cases, autism is associated with agents that cause birth defects.
At its core, Autism affects information processing in the brain.
This is what you need to know:
What Are You Looking For?
1. About Autism
2. Key Features
I. Impairments in Social Interaction
ii. Impairments in Communication
iii. Repetitive Behaviour
3. Causes
4. Pathophysiology
5. Neuropsychology
6. Diagnosis
7. Classification
8, Screening
9. Management
10. Society and Culture
11. Prognosis
12. Epidemiology
About Autism
While autism is often inherited, researchers suspect both environmental and genetic factors as causes. In rare cases, autism is associated with agents that cause birth defects. Autism affects information processing in the brain by altering how nerve cells and their synapses connect and organize. This is known as ASDs and is one of three recognized disorders in the autism spectrum.
The other two being:
– Asperger syndrome, which lacks delays in cognitive development and language
– Pervasive Developmental Disorder or PDD-NOS. This is diagnosed when the full set of criteria for Autism or Asperger syndrome are not met.
Early speech or behavioral interventions can help children with autism gain self-care, social, and communication skills. Although there is no known cure, there have been reported cases of children who recovered. Not many children with autism live independently after reaching adulthood, though some become successful. An autistic culture has developed, with some individuals seeking a cure and others believing autism should be accepted as a difference and not treated as a disorder.
Autism is a highly variable neurodevelopmental disorder that first appears during infancy or childhood, and generally follows a steady course without remission.
People with autism may be severely impaired in some respects but normal, or even superior, in others.
Overt symptoms gradually begin after the age of six months, become established by age two or three years, and tend to continue through adulthood, although often in more muted form. It is distinguished not by a single symptom, but by a characteristic triad of symptoms: impairments in social interaction; impairments in communication; and restricted interests and repetitive behaviour.
Other aspects, such as atypical eating, are also common but are not essential for diagnosis. Autism’s individual symptoms occur in the general population and appear not to associate highly, without a sharp line separating pathologically severe from common traits.
i. Impairments in Social Interaction
People with autism have social impairments and often lack the intuition about others that many people take for granted. Noted autistic Temple Grandin described her inability to understand the social communication of neurotypicals, or people with normal neural development, as leaving her feeling “like an anthropologist on Mars”.
Unusual social development becomes apparent early in childhood. Autistic infants show less attention to social stimuli, smile and look at others less often, and respond less to their own name. Autistic toddlers differ more strikingly from social norms; for example, they have less eye contact and turn-taking, and do not have the ability to use simple movements to express themselves, such as pointing at things. Three- to five-year-old children with autism are less likely to exhibit social understanding, approach others spontaneously, imitate and respond to emotions, communicate nonverbally, and take turns with others. However, they do form attachments to their primary caregivers. Most children with autism display moderately less attachment security than neurotypical children, although this difference disappears in children with higher mental development or less severe ASD. Older children and adults with ASD perform worse on tests of face and emotion recognition although this may be partly due to a lower ability to define a person’s own emotions.
Children with high-functioning autism suffer from more intense and frequent loneliness compared to non-autistic peers, despite the common belief that children with autism prefer to be alone. Making and maintaining friendships often proves to be difficult for those with autism. For them, the quality of friendships, not the number of friends, predicts how lonely they feel. Functional friendships, such as those resulting in invitations to parties, may affect the quality of life more deeply.
There are many anecdotal reports, but few systematic studies, of aggression and violence in individuals with ASD. The limited data suggest that, in children with intellectual disability, autism is associated with aggression, destruction of property, and tantrums.
ii. Impairments in Communication
About a third to a half of individuals with autism do not develop enough natural speech to meet their daily communication needs. Differences in communication may be present from the first year of life, and may include delayed onset of babbling, unusual gestures, diminished responsiveness, and vocal patterns that are not synchronized with the caregiver.
In the second and third years, children with autism have less frequent and less diverse babbling, consonants, words, and word combinations; their gestures are less often integrated with words.
Children with autism are less likely to make requests or share experiences, and are more likely to simply repeat others’ words (echolalia) or reverse pronouns. Joint attention seems to be necessary for functional speech, and deficits in joint attention seem to distinguish infants with ASD: for example, they may look at a pointing hand instead of the pointed-at object, and they consistently fail to point at objects in order to comment on or share an experience.

Children with autism may have difficulty with imaginative play and with developing symbols into language.
In a pair of studies, high-functioning children with autism aged 8–15 performed equally well as, and adults better than, individually matched controls at basic language tasks involving vocabulary and spelling. Both autistic groups performed worse than controls at complex language tasks such as figurative language, comprehension and inference.
As people are often sized up initially from their basic language skills, these studies suggest that people speaking to autistic individuals are more likely to overestimate what their audience comprehends.
iii. Repetitive Behaviour
Autistic individuals display many forms of repetitive or restricted behaviour, which the Repetitive Behaviour Scale-Revised (RBS-R) categorizes as follows:
– Stereotypy is repetitive movement, such as hand flapping, head rolling, or body rocking.
– Compulsive behavior is intended and appears to follow rules, such as arranging objects in stacks or lines.
– Sameness is resistance to change; for example, insisting that the furniture not be moved or refusing to be interrupted.
– Ritualistic behavior involves an unvarying pattern of daily activities, such as an unchanging menu or a dressing ritual.
This is closely associated with sameness and an independent validation has suggested combining the two factors.
– Restricted behavior is limited in focus, interest, or activity, such as preoccupation with a single television program, toy or game.
– Self-injury includes movements that injure or can injure the person, such as eye-poking, skin-picking, hand-biting and head-banging.
No single repetitive or self-injurious behavior seems to be specific to autism, but only autism appears to have an elevated pattern of occurrence and severity of these behaviors.
Other symptoms
Autistic individuals may have symptoms that are independent of the diagnosis, but that can affect the individual or the family.
An estimated 0.5% to 10% of individuals with ASD show unusual abilities, ranging from splinter skills such as the memorization of trivia to the extraordinarily rare talents of prodigious autistic savants. Many individuals with ASD show superior skills in perception and attention, relative to the general population. Sensory abnormalities are found in over 90% of those with autism, and are considered core features by some, although there is no good evidence that sensory symptoms differentiate autism from other developmental disorders.
Differences are greater for under-responsivity (for example, walking into things) than for over-responsivity (for example, distress from loud noises) or for sensation seeking (for example, rhythmic movements).
An estimated 60%–80% of autistic people have motor signs that include poor muscle tone, poor motor planning, and toe walking; deficits in motor coordination are pervasive across ASD and are greater in autism proper.
Parents of children with ASD have higher levels of stress. Siblings of children with ASD report greater admiration of and less conflict with the affected sibling than siblings of unaffected children and were similar to siblings of children with Down syndrome in these aspects of the sibling relationship. However, they reported lower levels of closeness and intimacy than siblings of children with Down syndrome; siblings of individuals with ASD have greater risk of negative well-being and poorer sibling relationships as adults.
It has long been presumed that there is a common cause at the genetic, cognitive, and neural levels for autism’s characteristic triad of symptoms. However, there is increasing suspicion that autism is instead a complex disorder whose core aspects have distinct causes that often co-occur.
Deletion (1), duplication (2) and inversion (3) are all chromosome abnormalities that have been implicated in autism.
Autism has a strong genetic basis. The diagnostic criteria require that symptoms become apparent in early childhood, typically before age three. Although the genetics of autism are complex and it is unclear whether ASD is explained more by rare mutations with major effects, or by rare multigene interactions of common genetic variants. Complexity arises due to interactions among multiple genes, the environment, and epigenetic factors which do not change DNA but are heritable and influence gene expression. Many genes have been associated with autism through sequencing the genomes of affected individuals and their parents.
Studies of twins suggest that heritability is 0.7 for autism and as high as 0.9 for ASD, and siblings of those with autism are about 25 times more likely to be autistic than the general population. However, most of the mutations that increase autism risk have not been identified.
Autism affects the amygdala, cerebellum, and many other parts of the brain.
Unlike many other brain disorders, such as Parkinson’s, autism does not have a clear unifying mechanism at either the molecular, cellular, or systems level; it is not known whether autism is a few disorders caused by mutations converging on a few common molecular pathways, or is (like intellectual disability) a large set of disorders with diverse mechanisms.
Autism appears to result from developmental factors that affect many or all functional brain systems, and to disturb the timing of brain development more than the final product. Neuroanatomical studies and the associations with teratogens strongly suggest that autism’s mechanism includes alteration of brain development soon after conception.
This anomaly appears to start a cascade of pathological events in the brain that are significantly influenced by environmental factors. Just after birth, the brains of children with autism tend to grow faster than usual, followed by normal or relatively slower growth in childhood. It is not known whether early overgrowth occurs in all children with autism. It seems to be most prominent in brain areas underlying the development of higher cognitive specialization.
From studies based on event-related potentials, transient changes to the brain’s electrical activity in response to stimuli, there is considerable evidence for differences in autistic individuals with respect to attention, orientation to auditory and visual stimuli, novelty detection, language and face processing, and information storage; several studies have found a preference for nonsocial stimuli.
For example, magnetoencephalography studies have found evidence in children with autism of delayed responses in the brain’s processing of auditory signals.
In the genetic area, relations have been found between autism and schizophrenia based on duplications and deletions of chromosomes; research showed that schizophrenia and autism are significantly more common in combination with 1q21.1 deletion syndrome.
Research on autism/schizophrenia relations for chromosome 15 (15q13.3), chromosome 16 (16p13.1) and chromosome 17 (17p12) are inconclusive.
Two major categories of cognitive theories have been proposed about the links between autistic brains and behaviour.
1. The first category focuses on deficits in social cognition.
Simon Baron-Cohen’s empathizing–systemizing theory postulates that autistic individuals can systemize—that is, they can develop internal rules of operation to handle events inside the brain—but are less effective at empathizing by handling events generated by other agents.
An extension, the extreme male brain theory, hypothesizes that autism is an extreme case of the male brain, defined psychometrically as individuals in whom systemizing is better than empathizing.
These theories are somewhat related to Baron-Cohen’s earlier theory of mind approach, which hypothesizes that autistic behavior arises from an inability to ascribe mental states to oneself and others. The theory of mind hypothesis is supported by the atypical responses of children with autism to the Sally–Anne test for reasoning about others’ motivations, and the mirror neuron system theory of autism described in Pathophysiology maps well to the hypothesis.
However, most studies have found no evidence of impairment in autistic individuals’ ability to understand other people’s basic intentions or goals; instead, data suggests that impairments are found in understanding more complex social emotions or in considering others’ viewpoints.
2. The second category focuses on nonsocial or general processing:
the executive functions such as working memory, planning, inhibition. In his review, Kenworthy states that “the claim of executive dysfunction as a causal factor in autism is controversial”, however, “it is clear that executive dysfunction plays a role in the social and cognitive deficits observed in individuals with autism”.
Tests of core executive processes such as eye movement tasks indicate improvement from late childhood to adolescence, but performance never reaches typical adult levels.
A strength of the theory is predicting stereotyped behavior and narrow interests; two weaknesses are that executive function is hard to measure and that executive function deficits have not been found in young children with autism.
Weak central coherence theory hypothesizes that a limited ability to see the big picture underlies the central disturbance in autism. One strength of this theory is predicting special talents and peaks in performance in autistic people. A related theory—enhanced perceptual functioning—focuses more on the superiority of locally oriented and perceptual operations in autistic individuals. These theories map well from the underconnectivity theory of autism.
Neither category is satisfactory on its own; social cognition theories poorly address autism’s rigid and repetitive behaviors, while the nonsocial theories have difficulty explaining social impairment and communication difficulties. A combined theory based on multiple deficits may prove to be more useful.
Diagnosis is based on behavior, not cause or mechanism. Under the DSM-5, autism is characterized by persistent deficits in social communication and interaction across multiple contexts, as well as restricted, repetitive patterns of behavior, interests, or activities.
These deficits are present in early childhood, typically before age three, and lead to clinically significant functional impairment. Sample symptoms include lack of social or emotional reciprocity, stereotyped and repetitive use of language or idiosyncratic language, and persistent preoccupation with unusual objects.
The disturbance must not be better accounted for by Rett syndrome, intellectual disability or global developmental delay. ICD-10 uses essentially the same definition.
Several diagnostic instruments are available. Two are commonly used in autism research:
– the Autism Diagnostic Interview-Revised (ADI-R) is a semistructured parent interview
– Autism Diagnostic Observation Schedule (ADOS) uses observation and interaction with the child.
The Childhood Autism Rating Scale (CARS) is used widely in clinical environments to assess severity of autism based on observation of children.
A pediatrician commonly performs a preliminary investigation by taking developmental history and physically examining the child. If warranted, diagnosis and evaluations are conducted with help from ASD specialists, observing and assessing cognitive, communication, family, and other factors using standardized tools, and taking into account any associated medical conditions.
Underdiagnosis and overdiagnosis are problems in marginal cases, and much of the recent increase in the number of reported ASD cases is likely due to changes in diagnostic practices. The increasing popularity of drug treatment options and the expansion of benefits has given providers incentives to diagnose ASD, resulting in some overdiagnosis of children with uncertain symptoms.
Conversely, the cost of screening and diagnosis and the challenge of obtaining payment can inhibit or delay diagnosis.
It is particularly hard to diagnose autism among the visually impaired, partly because some of its diagnostic criteria depend on vision, and partly because autistic symptoms overlap with those of common blindness syndromes or blind-isms.
Autism is one of the five pervasive developmental disorders (PDD), which are characterized by widespread abnormalities of social interactions and communication, and severely restricted interests and highly repetitive behaviour. These symptoms do not imply sickness, fragility, or emotional disturbance.
Of the five PDD forms, Asperger syndrome is closest to autism in signs and likely causes; Rett syndrome and childhood disintegrative disorder share several signs with autism, but may have unrelated causes; PDD not otherwise specified (PDD-NOS; also called atypical autism) is diagnosed when the criteria are not met for a more specific disorder. Unlike with autism, people with Asperger syndrome have no substantial delay in language development.
The terminology of autism can be bewildering, with autism, Asperger syndrome and PDD-NOS often called the autism spectrum disorders (ASD) or sometimes the autistic disorders, whereas autism itself is often called autistic disorder, childhood autism, or infantile autism. In this article, autism refers to the classic autistic disorder; in clinical practice, though, autism, ASD, and PDD are often used interchangeably. ASD, in turn, is a subset of the broader autism phenotype, which describes individuals who may not have ASD but do have autistic-like traits, such as avoiding eye contact.
About half of parents of children with ASD notice their child’s unusual behaviors by age 18 months, and about four-fifths notice by age 24 months. According to an article in the Journal of Autism and Developmental Disorders, failure to meet any of the following milestones “is an absolute indication to proceed with further evaluations.
Delay in referral for such testing may delay early diagnosis and treatment and affect the long-term outcome”.
– No babbling by 12 months.
– No gesturing (pointing, waving, etc.) by 12 months.
– No single words by 16 months.
– No two-word (spontaneous, not just echolalic) phrases by 24 months.
– Any loss of any language or social skills, at any age.
US and Japanese practice is to screen all children for ASD at 18 and 24 months, using autism-specific formal screening tests.In contrast, in the UK, children whose families or doctors recognize possible signs of autism are screened. It is not known which approach is more effective.
The main goals when treating children with autism are to lessen associated deficits and family distress, and to increase quality of life and functional independence. In general, higher IQs are correlated with greater responsiveness to treatment and improved treatment outcomes.
No single treatment is best and treatment is typically tailored to the child’s needs.
Families and the educational system are the main resources for treatment.
Studies of interventions have methodological problems that prevent definitive conclusions about efficacy, however the development of evidence-based interventions has advanced in recent years.
Although many psychosocial interventions have some positive evidence, suggesting that some form of treatment is preferable to no treatment, the methodological quality of systematic reviews of these studies has generally been poor, their clinical results are mostly tentative, and there is little evidence for the relative effectiveness of treatment options. Intensive, sustained special education programs and behaviour therapy early in life can help children acquire self-care, social, and job skills, and often improve functioning and decrease symptom severity and maladaptive behaviours; claims that intervention by around age three years is crucial are not substantiated.
Available approaches include applied behavior analysis (ABA), developmental models, structured teaching, speech and language therapy, social skills therapy, and occupational therapy. Among these approaches, interventions either treat autistic features comprehensively, or focalize treatment on a specific area of deficit.
There is some evidence that early intensive behavioral intervention (EIBI), an early intervention model based on ABA for 20 to 40 hours a week for multiple years, is an effective treatment for some children with ASD.
Two theoretical frameworks outlined for early childhood intervention include applied behavioral analysis (ABA) and developmental social pragmatic models (DSP). One interventional strategy utilizes a parent training model, which teaches parents how to implement various ABA and DSP techniques, allowing for parents to disseminate interventions themselves.
Various DSP programs have been developed to explicitly deliver intervention systems through at-home parent implementation. Despite the recent development of parent training models, these interventions have demonstrated effectiveness in numerous studies, being evaluated as a probable efficacious mode of treatment.
The rainbow-colored infinity is often used as a symbol for the diversity of the autism spectrum as well as neurodiversity in general.
The emergence of the autism rights movement has served as an attempt to encourage people to be more tolerant of those with autism. Through this movement, people hope to cause others to think of autism as a difference instead of a disease. Proponents of this movement wish to seek “acceptance, not cures.”
There have also been many worldwide events promoting autism awareness such as World Autism Awareness Day,
Light It Up Blue, Autism Sunday, Autistic Pride Day, Autreat, and others. There have also been many organizations dedicated to increasing the awareness of autism and the effects that autism has on someone’s life. These organizations include Autism Speaks, Autism National Committee, Autism Society of America, and many others.
Social-science scholars have had an increased focused on studying those with autism in hopes to learn more about “autism as a culture, transcultural comparisons… and research on social movements.” Media has had an influence on how the public perceives those with autism.
Rain Man, a film that won 4 Oscars, depicts a character with autism who has incredible talents and abilities. While many autistics don’t have these special abilities, there are some autistic individuals who have been successful in their fields.
There is no known cure. Children recover occasionally, so that they lose their diagnosis of ASD; this occurs sometimes after intensive treatment and sometimes not. It is not known how often recovery happens; reported rates in unselected samples of children with ASD have ranged from 3% to 25%.
Most children with autism acquire language by age five or younger, though a few have developed communication skills in later years.
Most children with autism lack social support, meaningful relationships, future employment opportunities or self-determination.
Although core difficulties tend to persist, symptoms often become less severe with age.
Few high-quality studies address long-term prognosis. Some adults show modest improvement in communication skills, but a few decline; no study has focused on autism after midlife. Acquiring language before age six, having an IQ above 50, and having a marketable skill all predict better outcomes; independent living is unlikely with severe autism. Most people with autism face significant obstacles in transitioning to adulthood.
Globally, autism affects an estimated 21.7 million people as of 2013, while Asperger syndrome affects a further 31.1 million.
The number of reported cases of autism increased dramatically in the 1990s and early 2000s. This increase is largely attributable to changes in diagnostic practices, referral patterns, availability of services, age at diagnosis, and public awareness, though unidentified environmental risk factors cannot be ruled out.
The available evidence does not rule out the possibility that autism’s true prevalence has increased; a real increase would suggest directing more attention and funding toward changing environmental factors instead of continuing to focus on genetics.
Boys are at higher risk for ASD than girls. The sex ratio averages 4.3:1 and is greatly modified by cognitive impairment: it may be close to 2:1 with intellectual disability and more than 5.5:1 without. Several theories about the higher prevalence in males have been investigated, but the cause of the difference is unconfirmed; one theory is that females are underdiagnosed.
Although the evidence does not implicate any single pregnancy-related risk factor as a cause of autism, the risk of autism is associated with advanced age in either parent, and with diabetes, bleeding, and use of psychiatric drugs in the mother during pregnancy.
The risk is greater with older fathers than with older mothers; two potential explanations are the known increase in mutation burden in older sperm, and the hypothesis that men marry later if they carry genetic liability and show some signs of autism. Most professionals believe that race, ethnicity, and socioeconomic background do not affect the occurrence of autism.
The Internet has helped autistic individuals bypass nonverbal cues and emotional sharing that they find so hard to deal with, and has given them a way to form online communities and work remotely. Sociological and cultural aspects of autism have developed: some in the community seek a cure, while others believe that autism is simply another way of being.
Useful Links
How to Create an Autism-Friendly Environment for Kids:
https://livingautism.com/create-autism-friendly-environment/
How to Discuss Puberty with Your Child Who Has Special Needs:
http://www.raisingarizonakids.com/2009/09/puberty-and-the-special-needs-child/
Teaching the Person with Autism How to Drive:
http://www.child-autism-parent-cafe.com/teaching-the-person-with-autism-how-to-drive.html
Coping With Stress: A Guide For Struggling Parents:
http://kidshealth.org/en/parents/stress-coping.html
The Importance of Self-Esteem for Kids With Learning and Attention Issues:
https://www.understood.org/en/friends-feelings/empowering-your-child/self-esteem/the-importance-of-self-esteem-for-kids-with-learning-and-attention-issues