Controversies in autism

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Diagnoses of autism have become more frequent since the 1980s, which has led to various controversies about both the cause of autism and the nature of the diagnoses themselves. Whether autism has mainly a genetic or developmental cause, and the degree of coincidence between autism and intellectual disability, are all matters of current scientific controversy as well as inquiry. There is also more sociopolitical debate as to whether autism should be considered a disability on its own. [1]

Scientific consensus holds that vaccines do not cause autism, but popular rumors and an article in a respected scientific journal, The Lancet, provoked concern among parents. The Lancet article was retracted for making false claims and because its author was found to be on the payroll of litigants against vaccine manufacturers.[2]

Epidemiology[edit]

Most recent reviews of epidemiology estimate a prevalence of one to two cases per 1,000 people for autism, and about six per 1,000 for ASD;[3] because of inadequate data, these numbers may underestimate the true prevalence of autism spectrum disorder (ASD).[4] ASD averages a 4.3:1 male-to-female ratio. The number of children on the autism spectrum has increased dramatically since the 1980s, at least partly due to changes in diagnostic practice; it is unclear whether prevalence has actually increased;[3] and as-yet-unidentified environmental risk factors cannot be ruled out.[5] The risk of autism is associated with several prenatal factors, including advanced parental age and diabetes in the mother during pregnancy.[6] ASD is associated with several genetic disorders[7] and epilepsy.[8] Autism is also associated with intellectual disability.[9]

Genetics[edit]

The role of genetic influence on ASD has been heavily researched over the past few years. ASD is considered to have polygenic traits since there is not a single risk factor, but multiple ones.[10]

Multiple twin and family studies have been conducted in order to observe any genetic influence in diagnosing ASD. The chance of both twins having ASD was significantly higher in identical twins than fraternal twins, concluding that ASD is heritable.[11] A reoccurring finding is that de novo (new mutation) copy number variants are a primary cause of ASD - they alter synaptic functions; germ line mutations can produce de novo CNVs.[12] These mutations can only be passed on to offspring; this explains the phenomenon that occurs when the child has symptoms of ASD, but the parents have no symptoms or history of ASD. De novo variants differ from person to person i.e one variant can cause ASD in one person, whereas another person would need multiple variants to cause the same disorder.[11] Loss of function variants occur in 16-18% of ASD diagnoses, which is nearly double the normal population.[10] These loss of function variants reduce function in the protein neurexin, which connects neurons at the synapse and is important for neurological development; deletion mutations of neurexin are also very common in people with autism, as well as other neurological disorders like schizophrenia, bipolar disorder, and ADHD.[13]

Gut microbiome has a relation to ASD. Excessive Clostridia spp. was found in children with ASD and gastrointestinal difficulties; Clostridia spp produces propionic acid which is impaired or in excess in people with ASD[14] Specifically, C. tetani and C. histolyticum are two species of this bacteria that affect people with ASD. C. tetani produces tetanus neurotoxin in the intestinal tract; C. histolyticum is a toxin producer that is abundant in people diagnosed with ASD.[15] Both of these could contribute to neurological symptoms.

There is also controversy over the Nature vs. Nurture debate. According to family studies, genetic and environmental factors have an equal influence on risk of ASD.[11]

Vaccines[edit]

The idea of a link between vaccines and autism has been extensively investigated and shown to be false.[16] The scientific consensus is that there is no relationship, causal or otherwise, between vaccines and incidence of autism,[17][18][19] and vaccine ingredients do not cause autism.[20]

Nevertheless, the anti-vaccination movement continues to promote myths, conspiracy theories and misinformation linking the two.[21] A developing tactic appears to be the "promotion of irrelevant research [as] an active aggregation of several questionable or peripherally related research studies in an attempt to justify the science underlying a questionable claim."[22]

Intelligence[edit]

The percentage of autistic individuals who also meet criteria for intellectual disability has been reported as anywhere from 25% to 70%, a wide variation illustrating the difficulty of assessing autistic intelligence.[23] For PDD-NOS the association with intellectual disability is much weaker.[9] The diagnosis of Asperger's excludes clinically significant delays in mental or cognitive skills.[24]

A 2007 study suggested that Raven's Progressive Matrices (RPM), a test of abstract reasoning, may be a better indicator of intelligence for autistic children than the more commonly used Wechsler Intelligence Scale for Children (WISC). Researchers suspected that the WISC relied too heavily on language to be an accurate measure of intelligence for autistic individuals. Their study revealed that the neurotypical children scored similarly on both tests, but the autistic children fared far better on the RPM than on the WISC. The RPM measures abstract, general and fluid reasoning, an ability autistic individuals have been presumed to lack.[25] A 2008 study found a similar effect, but to a much lesser degree and only for individuals with IQs less than 85 on the Wechsler scales.[26]

Facilitated Communication[edit]

Facilitated communication is a scientifically discredited technique[27] that attempts to facilitate communication by people with severe educational and communication disabilities. The facilitator holds or gently touches the disabled person's arm or hand during this process and attempts to help them move to type on a special keyboard. It was used by many hopeful parents of individuals with autism when it was first introduced during the early 1990s by Douglas Biklen, a professor at Syracuse University.[28]

There is widespread agreement within the scientific community and multiple disability advocacy organizations that FC is not a valid technique for authentically augmenting the communication skills of those with autism spectrum disorder.[29] Instead, research indicates that the facilitator is the source of the messages obtained through FC (involving ideomotor effect guidance of the arm of the patient by the facilitator).[30][31] Thus, studies have consistently found that patients are unable to provide the correct response to even simple questions when the facilitator does not know the answers to the questions (e.g., showing the patient but not the facilitator an object).[32] In addition, numerous cases have been reported by investigators in which disabled persons were assumed by facilitators to be typing a coherent message while the patient's eyes were closed or while they were looking away from or showing no particular interest in the letter board.[33] Despite the evidence opposing FC, many continue to use and promote this technique.[29]

Advocacy[edit]

Autism advocacy focuses on either acceptance or medical research. The autism rights movement (ARM) is a social movement that encourages autistic people, their caregivers and society to adopt a position of neurodiversity, accepting autism as a variation in functioning rather than a mental disorder to be cured.[34] The ARM advocates a variety of goals including a greater acceptance of autistic behaviors;[35] therapies that teach autistic individuals coping skills rather than therapies focused on imitating behaviors of neurotypical peers;[36] the creation of social networks and events that allow autistic people to socialize on their own terms;[37] and the recognition of the Autistic community as a minority group.[38] The movement is controversial. A common criticism against autistic activists is that the majority of them are "high-functioning" or have Asperger syndrome and do not represent the views of "low-functioning" autistic people.[39]

Pro-cure perspective[edit]

The puzzle piece ribbon is the most recognized symbol for autism awareness.

The pro-cure perspective is a view of autism as a disorder characterized by various impairments, mostly in communication and social interaction. Although positive traits such as savant syndrome may be recognized, they are not seen as outweighing the negatives. Pro-cure organizations generally favor the medical model of disability with regards to autism. They believe that the atypical behaviors of autistic individuals are a detriment to those individuals' social and professional success, and should therefore be reduced or eliminated through therapy. For instance, then-president Liz Feld of Autism Speaks stated that one-third of people with autism also have a seizure disorder, half suffer serious digestive complications, 49 percent wander, and more than 30 percent are nonverbal.[40]

Autism Speaks co-founder Suzanne Wright published a "Call for Action" at the time of the organization's first national policy summit in Washington, D.C., explaining the urgency of what she called the autism crisis.[41] In this essay, she equates children being autistic to being "missing" and "gravely ill", and details the exhausting experiences of their parents:

National Council on Severe Autism co-founder Jill Escher stated that understanding severe autism is important in getting families the help they need:[42]

Anti-cure perspective[edit]

Autism rainbow infinity
The rainbow-colored infinity symbol represents the diversity of the autism spectrum as well as the greater neurodiversity movement. Many autistic people prefer this symbol over any puzzle-piece based ones.[43]

"Curing" or "treating" autism is a controversial and politicized issue. Doctors and scientists are not sure of the cause(s) of autism yet many organizations like Autism Research Institute and Autism Speaks advocate researching a cure. Members of the various autism rights organizations view autism as a way of life rather than as a disease and thus advocate acceptance over a search for a cure.[44] Some advocates believe that common therapies for the behavioral and language differences associated with autism, like applied behavior analysis, are not only misguided but also unethical.[45]

The "anti-cure perspective" endorsed by the movement is a view that autism is not a disorder, but a normal occurrence—an alternate variation in brain wiring or a less common expression of the human genome.[44] Advocates of this perspective believe that autism is a unique way of being that should be validated, supported and appreciated rather than shunned, discriminated against or eliminated.[44][46] They believe quirks and uniqueness of autistic individuals should be tolerated as the differences of any minority group should be tolerated and that efforts to eliminate autism should not be compared, for example, to curing cancer but instead to the antiquated notion of curing left-handedness.[44][47] The ARM is a part of the larger disability rights movement, and as such acknowledges the social model of disability.[48] Within the model, struggles faced by autistic people are viewed as discrimination on the part of society rather than deficiencies on the part of autistic people.

John Elder Robison was a discussant for the Autism Social, Legal, and Ethical Research Special Interest Group at the 2014 International Meeting for Autism Research (IMFAR). He ended up taking the group to task, stating that the autism science community is headed for disaster if it does not change course on several factors – and noting for context the larger size of the US autistic community in proportion to other minority groups such as Jewish or Native American communities.

Robison asserted that autistic people need to be the ones providing oversight and governance for autism research. He condemned the use of words like "cure". He pointed out that researchers' explicit or implicit efforts to eradicate autistic people are a formula for disaster and need to stop. He also affirmed that memoirs and narratives written by autistic people are more trustworthy than writing about autism by nonautistics.[49]

Diagnostic complications[edit]

Although the 2013 fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) has more specificity, it also has reports of more limited sensitivity. Owing to the changes to the DSM and the lessening of sensitivity, there is the possibility that individuals who were diagnosed with autistic spectrum disorders (ASD) using the fourth revision (DSM-IV-TR) will not receive the same diagnosis with the DSM-5.

From the 933 individuals that were evaluated, 39 percent of the samples that were diagnosed with an ASD using the DSM-IV-TR criteria did not meet the DSM-5 criteria for that disorder.[unreliable medical source?][50] Essentially, the DSM-5 criteria no longer classified them with having ASD, deeming them without a diagnosis. It was likely that individuals that exhibited higher cognitive functioning and had other disorders, such as Asperger's or pervasive developmental disorder not otherwise specified (PDD-NOS), were completely excluded from the criteria. Also, it is more probable that younger children who do not exhibit the entirety of the symptoms and characteristics of ASD are more at risk of being excluded by the new criteria since they could have Asperger's as Asperger's disorder does not usually show symptoms until later in childhood. Because the onset age is different in Asperger's from autism, grouping together the disorders does not typically allow or distinguish the differentiating ages of onset, which is problematic in diagnosing. It is evident, through the various studies, that the number of people being diagnosed will be significantly diminished as well, which is prominently due to the DSM-5's new criteria.[50]

References[edit]

  1. ^ Morgan, Jules (2016-10-01). "Autism spectrum disorder: difference or disability?". The Lancet Neurology. 15 (11): 1126. doi:10.1016/S1474-4422(16)30002-3. ISSN 1474-4422.
  2. ^ The Editors Of The Lancet (February 2010). "Retraction--Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children". Lancet. 375 (9713): 445. doi:10.1016/S0140-6736(10)60175-4. PMID 20137807. Lay summaryBBC News (2010-02-02).
  3. ^ a b Newschaffer CJ, Croen LA, Daniels J, Giarelli E, Grether JK, Levy SE, Mandell DS, Miller LA, Pinto-Martin J, Reaven J, Reynolds AM, Rice CE, Schendel D, Windham GC (2007). "The epidemiology of autism spectrum disorders" (PDF). Annual Review of Public Health. 28: 235–58. doi:10.1146/annurev.publhealth.28.021406.144007. PMID 17367287. Archived from the original (PDF) on 2013-09-03.
  4. ^ Caronna EB, Milunsky JM, Tager-Flusberg H (June 2008). "Autism spectrum disorders: clinical and research frontiers". Archives of Disease in Childhood. 93 (6): 518–23. doi:10.1136/adc.2006.115337. PMID 18305076.
  5. ^ Rutter M (January 2005). "Incidence of autism spectrum disorders: changes over time and their meaning". Acta Paediatrica. 94 (1): 2–15. doi:10.1111/j.1651-2227.2005.tb01779.x. PMID 15858952.
  6. ^ Gardener H, Spiegelman D, Buka SL (July 2009). "Prenatal risk factors for autism: comprehensive meta-analysis". The British Journal of Psychiatry. 195 (1): 7–14. doi:10.1192/bjp.bp.108.051672. PMC 3712619. PMID 19567888.
  7. ^ Zafeiriou DI, Ververi A, Vargiami E (June 2007). "Childhood autism and associated comorbidities". Brain & Development. 29 (5): 257–72. doi:10.1016/j.braindev.2006.09.003. PMID 17084999.
  8. ^ Levisohn PM (2007). "The autism-epilepsy connection". Epilepsia. 48 Suppl 9 (Suppl 9): 33–5. doi:10.1111/j.1528-1167.2007.01399.x. PMID 18047599.
  9. ^ a b Chakrabarti S, Fombonne E (June 2001). "Pervasive developmental disorders in preschool children". JAMA. 285 (24): 3093–9. doi:10.1001/jama.285.24.3093. PMID 11427137.
  10. ^ a b Robinson EB, Neale BM, Hyman SE (December 2015). "Genetic research in autism spectrum disorders". Current Opinion in Pediatrics. 27 (6): 685–91. doi:10.1097/MOP.0000000000000278. PMC 4650984. PMID 26371945.
  11. ^ a b c Bourgeron T (2016-07-01). "Current knowledge on the genetics of autism and propositions for future research". Comptes Rendus Biologies. 339 (7–8): 300–7. doi:10.1016/j.crvi.2016.05.004. PMID 27289453.
  12. ^ Ronemus M, Iossifov I, Levy D, Wigler M (February 2014). "The role of de novo mutations in the genetics of autism spectrum disorders". Nature Reviews. Genetics. 15 (2): 133–41. doi:10.1038/nrg3585. PMID 24430941.
  13. ^ Chen J, Yu S, Fu Y, Li X (2014-09-11). "Synaptic proteins and receptors defects in autism spectrum disorders". Frontiers in Cellular Neuroscience. 8: 276. doi:10.3389/fncel.2014.00276. PMC 4161164. PMID 25309321.
  14. ^ Frye RE, Rose S, Slattery J, MacFabe DF (2015-05-07). "Gastrointestinal dysfunction in autism spectrum disorder: the role of the mitochondria and the enteric microbiome". Microbial Ecology in Health and Disease. 26: 27458. doi:10.3402/mehd.v26.27458. PMC 4425813. PMID 25956238.
  15. ^ Li Q, Han Y, Dy AB, Hagerman RJ (2017). "The Gut Microbiota and Autism Spectrum Disorders". Frontiers in Cellular Neuroscience. 11: 120. doi:10.3389/fncel.2017.00120. PMC 5408485. PMID 28503135.
  16. ^ Taylor, Luke E.; Swerdfeger, Amy L.; Eslick, Guy D. (2014-06-17). "Vaccines are not associated with autism: an evidence-based meta-analysis of case-control and cohort studies". Vaccine. 32 (29): 3623–3629. doi:10.1016/j.vaccine.2014.04.085. ISSN 1873-2518. PMID 24814559.
  17. ^ Bonhoeffer J, Heininger U (June 2007). "Adverse events following immunization: perception and evidence" (PDF). Current Opinion in Infectious Diseases. 20 (3): 237–46. doi:10.1097/QCO.0b013e32811ebfb0. PMID 17471032.
  18. ^ Boseley S (February 2, 2010). "Lancet retracts 'utterly false' MMR paper". The Guardian. Retrieved February 2, 2010.
  19. ^ Taylor LE, Swerdfeger AL, Eslick GD (June 2014). "Vaccines are not associated with autism: an evidence-based meta-analysis of case-control and cohort studies". Vaccine. 32 (29): 3623–9. doi:10.1016/j.vaccine.2014.04.085. PMID 24814559.
  20. ^ "Vaccines Do Not Cause Autism Concerns". Centers for Disease Control and Prevention. 2018-12-12. Retrieved 2019-02-07.
  21. ^ "How autism myths came to fuel anti-vaccination movements".
  22. ^ Foster, Craig A.; Ortiz, Sarenna M. (2017). "Vaccines, Autism, and the Promotion of Irrelevant Research: A Science-Pseudoscience Analysis". Skeptical Inquirer. 41 (3): 44–48. Retrieved 6 October 2018.
  23. ^ Dawson M, Mottron L, Gernsbacher MA (2008). "Learning in autism" (PDF). In Byrne JH (-in-chief), Roediger HL III (vol.) (ed.). Learning and Memory: A Comprehensive Reference. 2. Academic Press. pp. 759–72. doi:10.1016/B978-012370509-9.00152-2. ISBN 978-0-12-370504-4.
  24. ^ DSM-IV-TR Diagnostical and Statistical Manual of Mental Disorders Fourth edition text revision. American Psychiatric Association, Washington DC. 2000. p. 80.
  25. ^ Dawson M, Soulières I, Gernsbacher MA, Mottron L (August 2007). "The level and nature of autistic intelligence". Psychological Science. 18 (8): 657–62. doi:10.1111/j.1467-9280.2007.01954.x. PMC 4287210. PMID 17680932. Lay summaryScienceDaily (2007-08-05).
  26. ^ Bölte S, Dziobek I, Poustka F (April 2009). "Brief report: The level and nature of autistic intelligence revisited". Journal of Autism and Developmental Disorders. 39 (4): 678–82. doi:10.1007/s10803-008-0667-2. PMID 19052857.
  27. ^ Vyse, Stuart. "Autism Wars: Science Strikes Back". Skeptical Inquirer Online. Skeptical Inquirer. Retrieved 28 November 2018.
  28. ^ "Institute on Communication and Inclusion". Syracuse University School of Education. Retrieved April 28, 2017.
  29. ^ a b Hemsley, Bronwyn; Bryant, Lucy; Schlosser, Ralf; Shane, Howard; Lang, Russell; Paul, Diane; Benajee, Meher; Ireland, Marie (2018). "Systematic review of facilitated communication 2014-2018 finds no new evidence that messages delivered using facilitated communication are authored by the person with the disability". Autism and Developmental Language Impairments. 3: 1–8. doi:10.1177/2396941518821570. Retrieved 22 May 2019.
  30. ^ Lilienfeld; et al. "Why debunked autism treatment fads persist". Science Daily. Emory University. Retrieved 10 November 2015.
  31. ^ Ganz, Jennifer B.; Katsiyannis, Antonis; Morin, Kristi L. (February 2017). "Facilitated Communication". Intervention in School and Clinic. 54: 52–56. doi:10.1177/1053451217692564.
  32. ^ Montee, B B; Miltenberger, R G; Wittrock, D; Watkins, N; Rheinberger, A; Stackhaus, J (1995). "An experimental analysis of facilitated communication". Journal of Applied Behavior Analysis. 28 (2): 189–200. doi:10.1901/jaba.1995.28-189. PMC 1279809. PMID 7601804.
  33. ^ Goldacre, Ben (2009-12-05). "Making contact with a helping hand". The Guardian. Retrieved 10 November 2015.
  34. ^ Solomon A (2008-05-25). "The autism rights movement". New York. Archived from the original on 27 May 2008. Retrieved 2008-05-27.
  35. ^ Mission Statement. Archived 2013-04-21 at the Wayback Machine Autism Acceptance Project. Retrieved on 2008-11-24.
  36. ^ Mission Statement. Aspies for Freedom. Retrieved on 2008-11-24.
  37. ^ Autism Network International presents Autreat. (2008-05-23) AIN.
  38. ^ "Declaration From the Autism Community That They Are a Minority Group" (Press release). PRWeb, Press Release Newswire. 2004-11-18. Retrieved 2007-11-07.
  39. ^ Jaarsma, Pier; Welin, Stellan (2012). "Autism as a natural human variation: reflections on the claims of the neurodiversity movement". Health care analysis: HCA: journal of health philosophy and policy. 20 (1): 20–30. doi:10.1007/s10728-011-0169-9. ISSN 1573-3394. Retrieved 16 June 2019.
  40. ^ Feld, Liz (25 August 2015). "A call for unity". Autism Speaks. Archived from the original on 2018-06-15. Retrieved 10 December 2016.
  41. ^ Wright, Suzanne (2013-11-11). "Autism Speaks to Washington - A Call for Action". Autism Speaks. Archived from the original on 2014-07-15. Retrieved 2014-07-15.
  42. ^ "New Advocacy Group Seeks Realistic Solutions for Severely Disabled Autistics". National Council on Severe Autism. Retrieved 7 June 2019.
  43. ^ Muzikar D (April 20, 2015). "The Autism Puzzle Piece: A symbol that's going to stay or go?". The Art of Autism. Retrieved April 1, 2017.
  44. ^ a b c d Harmon, Amy. Neurodiversity Forever; The Disability Movement Turns to Brains. The New York Times, May 9, 2004. Retrieved on 2007-11-08.
  45. ^ Dawson, Michelle. The Misbehaviour of Behaviourists. (2004-01-18). Retrieved on 2007-01-23.
  46. ^ Gal L (2007-06-28). "Who says autism's a disease?". Haaretz. Archived from the original on 1 July 2007. Retrieved 2007-07-16.
  47. ^ "In Support of Michelle Dawson and Her Work". Autistics.org. Archived from the original on 2012-02-15. Retrieved 2012-03-21.
  48. ^ Waltz M (2013). Autism: A Social and Medical History. London: Palgrave Macmillan. ISBN 978-0-230-52750-8.
  49. ^ John Robison at IMFAR: On Autism Rights, Ethics, & Priorities
  50. ^ a b Barton ML, Robins DL, Jashar D, Brennan L, Fein D (May 2013). "Sensitivity and specificity of proposed DSM-5 criteria for autism spectrum disorder in toddlers". Journal of Autism and Developmental Disorders. 43 (5): 1184–95. doi:10.1007/s10803-013-1817-8. PMC 3684196. PMID 23543293.