Autism spectrum

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The autism spectrum, also called autism spectrum disorders (ASD) or autism spectrum conditions (ASC), with the word autistic sometimes replacing autism, is a spectrum of psychological conditions characterized by widespread abnormalities of social interactions and communication, as well as severely restricted interests and highly repetitive behavior.[1]

The three main forms of ASD are autism, Asperger syndrome, and PDD-NOS. Autism forms the core of the autism spectrum disorders. Asperger syndrome is closest to autism in signs and likely causes. Pervasive developmental disorder not otherwise specified (PDD-NOS) is diagnosed when the criteria are not met for a more specific disorder. Some sources also include Rett syndrome and childhood disintegrative disorder, which share several signs with autism but may have unrelated causes.[2] Unlike autism, Asperger's has no significant delay in language development.[3]

The terminology of autism can be bewildering, with autism, Asperger's and PDD-NOS sometimes called the autistic disorders instead of ASD,[4] whereas autism itself is often called autistic disorder, childhood autism, or infantile autism. ASD, in turn, is a subset of the broader autism phenotype (BAP), which describes individuals who may not have ASD but do have autistic-like traits, such as avoiding eye contact.[5]

One review estimated a prevalence of at least 1.3 per 1,000 for autism and 6.0–6.5 per 1,000 for ASD; PDD-NOS was the vast majority of ASD, Asperger's was about 0.3 per 1,000 and the atypical forms childhood disintegrative disorder and Rett syndrome were much rarer.[6]

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[edit] Autistic traits

Behaviorally, certain characteristics identify the autism spectrum. The type, severity and/or number of autistic traits present determines the severity of autism in the individual. These autistic traits may be beneficial for some disciplines like science, mathematics, engineering and computer programming. Some autistic individuals might show a marked proficiency in rote memorization which may help learn the foundation of these subjects; however, the exceptionally good aptitude (in these subjects) of high functioning autistic spectrum persons may be due to their ability to readily identify patterns and apply them consistently to new situations outside of established knowledge or teaching. These savant skills, although popularly considered to be a major part of autistic disorders, are evident only in a small fraction of autistic individuals, with estimates of the fraction ranging from 0.5 to 10%.[7]

A 2007 study found that, contrary to popular belief, people on the autism spectrum are capable of reading facial expressions, social reasoning and understanding stereotypes. Eighteen children ages 10 to 14 were able to attribute a range of mental states to dynamic and static facial expressions, but not as great as their neurotypical peers. The autistic children were better at recognizing mental states when the eyes and mouth conveyed information than when these facial features were static and neutral. In a second experiment, children 11 to 15 were just as capable as their neurotypical peers at interpreting mental states whether it was the eyes in isolation or in the context of the whole face.[8]

Autistic people may be prone to commiting social faux pas due to an inability to predict the reactions of and understand the intent, needs and desires of those around them[citation needed]. This may cause neglect of social niceties, like knocking on doors before entering or returning a greeting. Similarly, they may be overly trusting or paranoid of strangers[citation needed]. Autistic children generally want to develop social relationships and are actually able to build relationships with peers through social skills training.[9] People with autism can also be taught how society works by using virtual reality simulations to learn about the complex rules of society.[10] Being on the autism spectrum does not keep these individuals from understanding social roles and stereotypes in a society, many of them can understand the role of a cashier in a super market when locking doors in a bad neighborhood.[11]

[edit] Diagnostic criteria and techniques

When the rising prevalence of autism spectrum disorders sparked research in the late 1990s, medical opinion initially attributed the increase to improved diagnostic screening or changes in the definition of autism. In 1994, the fourth major revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) was published with updated criteria for the diagnosis of autism and autism spectrum disorders.[12] Professional medical associations, including the American Academy of Pediatrics, say that this revision was an important factor in increasing the apparent prevalence of autism and a 2005 study by Mayo Clinic researchers found increases in autistic spectrum disorder diagnoses followed the revisions in DSM criteria and changes in funding for special education programs.[13]

An increased awareness of autistic spectrum disorders by parents and pediatricians may have also led to increased reporting of Autism due to 'case substitution', which occurs when children with other disorders are identified as autistic.[14] This misdiagnosis may occur for several reasons including an increase in government funding for care of children diagnosed as autistic, but not for children with a similar degree of disability and need. If this is occurring, it means that children who in the past would probably have been diagnosed as having a learning disability or a psychiatric disorder, or not diagnosed at all, are recorded as cases of autistic spectrum disorder.[15]

Dr. Fred Volkmar, a Yale University autism researcher, has said that "diagnostic substitution" was prompted by better services for autism.[16]

Many autism therapies have arisen to treat the core symptoms of autism. Simpson (2005) identified four scientifically-based treatments for learners with Autism Spectrum Disorders, including Applied Behavior Analysis, Discrete Trial Training, Pivotal Response Therapy, and Strain & Hoyson's "Learning Experiences: An Alternative Program for Preschoolers and Parents."[17]

[edit] References

  1. ^ World Health Organization (2006). "F84. Pervasive developmental disorders", International Statistical Classification of Diseases and Related Health Problems, 10th ed. (ICD-10). Retrieved on 2007-06-25. 
  2. ^ Lord C, Cook EH, Leventhal BL, Amaral DG (2000). "Autism spectrum disorders". Neuron 28 (2): 355–63. doi:10.1016/S0896-6273(00)00115-X. PMID 11144346. 
  3. ^ American Psychiatric Association (2000). "Diagnostic criteria for 299.80 Asperger's Disorder (AD)", Diagnostic and Statistical Manual of Mental Disorders, 4th ed., text revision (DSM-IV-TR). ISBN 0890420254. 
  4. ^ Freitag CM (2007). "The genetics of autistic disorders and its clinical relevance: a review of the literature". Mol Psychiatry 12 (1): 2–22. doi:10.1038/sj.mp.4001896. PMID 17033636. 
  5. ^ Piven J, Palmer P, Jacobi D, Childress D, Arndt S (1997). "Broader autism phenotype: evidence from a family history study of multiple-incidence autism families" (PDF). Am J Psychiatry 154 (2): 185–90. PMID 9016266. 
  6. ^ Fombonne E (2005). "Epidemiology of autistic disorder and other pervasive developmental disorders". J Clin Psychiatry 66 (Suppl 10): 3–8. PMID 16401144. 
  7. ^ Treffert DA (2006). Savant syndrome: an extraordinary condition—a synopsis: past, present, future. Wisconsin Medical Society. Retrieved on 2008-03-24.
  8. ^ Back E, Ropar D, Mitchell P (2007). "Do the eyes have it? inferring mental states from animated faces in autism". Child Dev 78 (2): 397–411. doi:10.1111/j.1467-8624.2007.01005.x. Lay summary – ScienceDaily (2007-03-27). 
  9. ^ Indiana University (2006-07-13). "New book offers social skills solutions for children with autism spectrum disorders". Press release. Retrieved on 2008-02-16.
  10. ^ "Virtual Reality Teaches Autistic Children Street Crossing, Study Suggests" . Lay summary – ScienceDaily (2008-01-29). 
  11. ^ Hirschfeld L, Bartmess E, White S, Frith U (2007). "Can autistic children predict behavior by social stereotypes?". Curr Biol 17 (12): R451–2. doi:10.1016/j.cub.2007.04.051. PMID 17580071. Lay summary – ScienceDaily (2007-06-19). 
  12. ^ Tidmarsh L, Volkmar FR (2003). "Diagnosis and epidemiology of autism spectrum disorders". Can J Psychiatry 48 (8): 517–25. PMID 14574827. 
  13. ^ Barbaresi WJ, Katusic SK, Colligan RC, Weaver AL, Jacobsen SJ (2005). "The incidence of autism in Olmsted County, Minnesota, 1976-1997: results from a population-based study". Arch Pediatr Adolesc Med 159 (1): 37–44. doi:10.1001/archpedi.159.1.37. PMID 15630056. 
  14. ^ Shattuck PT (2006). "The contribution of diagnostic substitution to the growing administrative prevalence of autism in US special education". Pediatrics 117 (4): 1028–37. doi:10.1542/peds.2005-1516. PMID 16585296. Lay summary (2006-04-03). 
  15. ^ Pettus A (2008). "A spectrum of disorders". Harv Mag 110 (3): 27–31, 89–91. 
  16. ^ "Uncovering autism's mysteries: Is there more autism? Or just a new definition?", Associated Press, 2003-03-02. Retrieved on 2007-12-30. "'Autism is kind of a fashionable diagnosis,' Volkmar said. 'Everybody's interested in getting better services.'" 
  17. ^ Simpson R.L. (2005). "Evidence-based practicies and students with autism spectrum disorders". Focus on Autism and other Developmental Disabilities 20 (3): 140-149. 

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