Autism is a disorder of neural development characterized by impaired social interaction and communication, as well as by restricted and repetitive behavior.. Generally, these signs begin prior to a child’s third birthday1 . Autism effects information processing in the brain because it alters how nerve cells and their synapses (pictured at left) connect and organize; however, exactly how this occurs is not well understood. Autism is one of three recognized disorders in the autism spectrum (ASDs), the other two being Asperger syndrome (which, doesn’t result in delays in cognitive development and language) and Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS ) which is diagnosed when the full set of criteria for either autism or Asperger syndrome are not met2 .
Autism has been found to have a strong genetic base, however, they are complex and it is unclear whether ASD can be explained more by rare mutations or by rare combinations of common genetic variants. There have been rare cases where autism has been strongly associated with the same agents that cause birth defects. Controversy surround other proposed environmental causes such as heavy metals, pesticides, or childhood vaccines. Currently, however, the vaccine hypotheses are biologically implausible and lack convincing scientific evidence3 . The prevalence of autism is about 1 – 2 per one thousand (1,000) people worldwide; however, the Centers for Disease Control and Prevention (CDC) reports approximately 9 per one thousand (1,000) children in the United States are diagnosed with ASD4 . The number of people diagnosed with autism has increased dramatically since the 1980s – due in part to changes in the diagnostic practice; the question of whether the actual prevalence has increased is yet to be resolved5 .
In most cases, parents report having noticed the signs (of autism) in the first two (2) years of their child’s life. These signs usually develop gradually, however, some autistic children have developed more normal initially and then regressed. Due to this early onset of symptoms, early behavioral or cognitive intervention can help a child with autism to gain self-care, social, and communications skills. Along those lines, it should be noted that although there aren’t many children with autism who are able to live independently after reaching adulthood, some are able to become successful.
Autism is a highly variable neuro-developmental disorder6 appearing first during infancy or early childhood, and generally following a steady course without remission. Overt symptoms – meaning that they are observable or readily apparent – gradually develop after the age of six (6) months, become established by the age of two to three years-old, and continue through adulthood – usually in a more muted form. Autism is not distinguished by a single symptom, but by a characteristic triad of symptoms: impairments in social interaction; impairments in communication; and restricted interest and repetitive behavior. There are other aspects, such as atypical eating, which are common but not essential to diagnosis of the condition. Autism’s individual symptoms occur in the general population and appear not to associate highly without a sharp line separating pathologically severe traits from common traits7 ,
What effects does autism have?
Social development
Social deficits distinguish autism and related spectrum disorders from other developmental disorders. People with autism generally [emphasis added ] have social impairments and often lack the intuition about others that many take for granted. Noted autistic Temple Grandin once described her inability to understand the social communications of neurotypicals (persons with normal development) as leaving her feeling “like an anthropologist on Mars”.
T he 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. In toddlers, the difference from social norms is even more striking; for example, they have less eye contact and turn taking, and do not have the ability to use simple movements to express themselves. In children three to five years-old, the tendency is to show less social understanding, not approaching other children or adults spontaneously, and limited or no imitating and responding to emotions. Additionally they tend not to communicate verbally and have difficulty taking turns with other children. One positive trait that they do show is the ability to perform is to bond and form attachment to their primary caregiver. Generally, older children and adults with ASD perform worse on tests involving face and emotion recognition.
Children with high-functioning autism8 suffer from more intense and frequent loneliness when compared with their non-autistic peers. This is despite the commonly accepted belief that children with autism prefer to be alone. The process of making and maintaining friendships is often difficult for a person with autism. For those, the quality of friendships rather than the number of friends they have, will predict how lonely they might feel.
There are many anecdotal reports, but few systematic studies, involving aggression and violence in individuals with ASD. Limited data suggest that, in children with mental retardation9 , the autism has been associated with aggression, destruction of property, and tantrums. In a 2007 study, parents of sixty-seven (67) children with ASD were interviewed and the results of those interviews indicated that about two-thirds of the children experienced periods with severe tantrums. Additionally, approximately one-third of these children also had a history of aggression along with the tantrums.
Communication
Research has indicated that approximately one-third to one-half of individuals with autism do not develop sufficient natural speech to meet their daily communication needs10 . Differences in communication can be present from the first year of life, and can include: delayed onset of babbling, unusual gestures, diminished responsiveness, and vocal patterns that are not synchronized with the parent / caregiver. By the age of two years-old, a child with autism tends to have less frequent and less diverse babbling, consonants, words, and word combinations; additionally, their gestures tend to be less integrated with their words. Research has shown that children with autism are less likely to make requests or share experiences, and are more likely to simply repeat others’ words (echolalia11 ) or to reverse pronouns. Joint attention seems to be necessary for functional speech, and deficits in joint attention seem to distinguish infants with ASD.
Repetitive behavior
Autistic individuals tend to display many forms of repetitive or restricted behavior which the Repetitive Behavior Scale-Revised (RBS-R)12 categorizes as follows:
Stereotypy is a repetitive movement such as hand-flapping, making sounds, head rolling, or body rocking.
Compulsive behavior is intended and appears to follow rules, such as arranging objects in stacks or lines.
Sameness is a resistance to change; for example, insisting that furniture not be moved or refusing to be interrupted.
Ritualistic behavior involves an unvarying pattern of daily activities such as a menu that does not change or a dressing ritual. This behavior 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 a pre-occupation 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. A 2007 study indicated that this particular behavior effects approximately thirty-percent (30%) of children with ASD.
Autistic individuals may experience symptoms which are independent of the diagnosis, but that can affect the individual or their family13 . An estimated 0.5% to 10% of individuals with ASD show unusual abilities that range 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 population14 . Sensory abnormalities are found in over ninety percent (90%) of those with autism, and are considered core features by some, although there is no conclusive evidence that sensory symptoms differentiate autism from other developmental disorders15 . These differences are more pronounced as far as under-responsivity (for example, walking into things) than for over-responsivity (for example, distress from loud noises) or sensation seeking (for example, rhythmic movements). An estimated sixty percent (60%) to eighty percent (80%) of people with autism have motor signs that include poor muscle tone, poor motor planning, and toe walking; additionally deficits in motor coordination are pervasive across ASD and are greater in autism particularly.
Unusual eating patterns occur in approximately three-quarters (¾) of children with ASD, to the point that it was formerly a diagnostic indicator. Selectivity is the most common problem, however, eating rituals as well as food refusal can also occur, but do not appear to result in malnutrition. Although many children with autism also experience gastrointestinal (GI) symptoms, there is a lack of published data to support the theory that autistic children have more – or different – GI symptoms than usual. The exact relationship between GI problems and ASD is unclear.
1American Psychiatric Association (2000) Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) 4th edition
2Johnson C.P.; Myers, S.M.; “Identification and evaluation of children with autism spectrum disorders“, Pediatrics , pp. 1183 – 1215
3Gerber, J.S., Offit, P.A. (2009) “Vaccines and autism: a tale of shifting hypotheses“, Clinical Infectious Disease, pp 456 – 461
4CDC Data (May 13, 2010) “Autism Spectrum Disorders – Data & Statistics“
5Newschaffer, C.J.; Croen, L.A., Daniels, J, et. al. (2007) “The epidemiology of autism spectrum disorders“, Annual Review of Public Health , pp. 235
6Greschwind, D.H. (2008) “Autism: many genes, common pathways“, Cell magazine , pp. 391 – 395
7London, E. (2007) “The role of the neurobiologist in redefining the diagnosis of autism“, Brain Pathology, pp. 408 – 411
8High-functioning autism (HFA ) is an informal term applied to persons with autism who are deemed to be “higher functioning” than others with autism, by one or more metrics. There is no consensus as to this definition and HFA is not yet a recognized diagnosis in the DSM-IV-TR.
Source: “Autism and Asperger syndrome: an overview “, Revista brasileira de psiquiatria (1999)
9Mental retardation is a generalized disorder that appears before adulthood and is characterized by significantly impaired cognitive function as well as deficits in two (2) or more adaptive behaviors.
Source: Wikipedia ( http://en.wikipedia.org/wiki/Mental_retardation )
10Noens, I.; Verpoorten, R; et. al (2006) “The ComFor: an instrument for the indication of augmentative communications in people with autism and intellectual disability“, Journal of Intellectual Disability Resources. pp. 621 – 632
11 Echolalia is the automatic repetition of vocalizations made by another person.
Source: Wikipedia.com ( http://en.wikipedia.org/wiki/Echolalia )
12For a detailed explanation of the Repetitive Behavior Scale-Revised , see: http://gradworks.umi.com/31/48/3148184.html
13Filipek, P.A.; Accardo, P.J.; et. al “The screening and diagnosis of autistic spectrum disorder“, Journal of Autism Development Disorder, pp. 439 – 484
14Treffert, D.A; “The savant syndrome: an extraordinary condition. A synopsis: past, present, future“
15Rogers, S.J.; Ozonoff, S.; (2005) “What do we know about sensory dysfunction in autism? A critical review of the empirical evidence.”, Journal of Childhood Psychology & Psychiatry, pp. 1255 – 1268