Many causes of autism, including environmental and genetic factors, have been recognized or proposed, but understanding of the theory of causation of autism is incomplete.[1] Attempts have been made to incorporate the known genetic and environmental causes into a comprehensive causative framework.[2] ASD (autism spectrum disorder) is a neurodevelopmental disorder marked by impairments in communicative ability and social interaction, as well as restricted and repetitive behaviors, interests, or activities not suitable for the individual's developmental stage. The severity of symptoms and functional impairment vary between individuals.[3]
There are many known environmental, genetic, and biological causes of autism. Research indicates that genetic factors are predominate in the appearance of autism; however, the heritability of autism is complex, and many of the genetic interactions involved are unknown.[1] In rare cases, autism has been associated with agents that cause birth defects.[4] Many other causes have been proposed.
Different underlying brain dysfunctions have been hypothesized to result in the common symptoms of autism, just as completely different brain types result in intellectual disability.[1][5] In recent years, the prevalence and number of people diagnosed with the disorder have increased dramatically. There are many potential reasons for this occurrence, particularly the changes in the diagnostic criteria for autism.[6]
Environmental factors that have been claimed to contribute to autism or exacerbate its symptoms, or that may be important to consider in future research, include certain foods,[7] infectious disease, heavy metals, solvents, diesel exhaust, PCBs, phthalates and phenols used in plastic products, pesticides, brominated flame retardants, alcohol, smoking, and illicit drugs.[6] Among these factors, vaccines have attracted much attention, as parents may first become aware of autistic symptoms in their child around the time of a routine vaccination, and parental concern about vaccines has led to a decreasing uptake of childhood immunizations and an increasing likelihood of measles outbreaks.[8][9] However, there is overwhelming scientific evidence showing that there is no causal association between the measles-mumps-rubella (MMR) vaccine and autism. Although there is no definitive evidence that the vaccine preservative thimerosal causes autism, studies have indicated a possible link between thimerosal and autism in individuals with a hereditary predisposition for autoimmune disorders.[10][11] In 2007, the Center for Disease Control stated there was no support for a link between thimerosal and autism, citing evidence from several studies, as well as a continued increase in autism cases following the removal of thimerosal from childhood vaccines. [12]
^ abcWaye MM, Cheng HY (April 2018). "Genetics and epigenetics of autism: A Review". Psychiatry and Clinical Neurosciences (Review). 72 (4): 228–244. doi:10.1111/pcn.12606. eISSN 1440-1819. PMID 28941239. S2CID 206257210.
^Sarovic D (November 2021). "A Unifying Theory for Autism: The Pathogenetic Triad as a Theoretical Framework". Frontiers in Psychiatry (Review). 12: 767075. doi:10.3389/fpsyt.2021.767075. PMC 8637925. PMID 34867553. S2CID 244119594.
^American Psychiatric Association (2022). Diagnostic and statistical manual of mental disorders: DSM-5-TR (5th ed.). American Psychiatric Association Publishing. doi:10.1176/appi.books.9780890425787. ISBN 978-0-89042-575-6. S2CID 249488050.
^Arndt TL, Stodgell CJ, Rodier PM (2005). "The teratology of autism". International Journal of Developmental Neuroscience (Review). 23 (2–3): 189–199. doi:10.1016/j.ijdevneu.2004.11.001. PMID 15749245. S2CID 17797266.
^ abSalari N, Rasoulpoor S, Rasoulpoor S, Shohaimi S, Jafarpour S, Abdoli N, et al. (July 2022). "The global prevalence of autism spectrum disorder: a comprehensive systematic review and meta-analysis". Italian Journal of Pediatrics. 48 (1): 112. doi:10.1186/s13052-022-01310-w. PMC 9270782. PMID 35804408.
^Quan J, Panaccione N, King JA, Underwood F, Windsor JW, Coward S, et al. (March 2019). "A257 Association Between Celiac Disease and Autism Spectrum Disorder: A Systematic Review". Journal of the Canadian Association of Gastroenterology. 2 (Supplement_2): 502–503. doi:10.1093/jcag/gwz006.256. ISSN 2515-2084. PMC 6512700.
^Wilder-Smith AB, Qureshi K (March 2020). "Resurgence of Measles in Europe: A Systematic Review on Parental Attitudes and Beliefs of Measles Vaccine". Journal of Epidemiology and Global Health. 10 (1): 46–58. doi:10.2991/jegh.k.191117.001. PMC 7310814. PMID 32175710.
^Gidengil C, Chen C, Parker AM, Nowak S, Matthews L (October 2019). "Beliefs around childhood vaccines in the United States: A systematic review". Vaccine. 37 (45): 6793–6802. doi:10.1016/j.vaccine.2019.08.068. PMC 6949013. PMID 31562000.
^Di Pietrantonj C, Rivetti A, Marchione P, Debalini MG, Demicheli V, et al. (Cochrane Acute Respiratory Infections Group) (November 2021). "Vaccines for measles, mumps, rubella, and varicella in children". The Cochrane Database of Systematic Reviews. 2021 (11): CD004407. doi:10.1002/14651858.CD004407.pub5. PMC 8607336. PMID 34806766.
^Kern JK, Geier DA, Mehta JA, Homme KG, Geier MR (December 2020). "Mercury as a hapten: A review of the role of toxicant-induced brain autoantibodies in autism and possible treatment considerations". Journal of Trace Elements in Medicine and Biology. 62: 126504. doi:10.1016/j.jtemb.2020.126504. PMID 32534375. S2CID 219468115.
^"Timeline: Thimerosal in Vaccines (1999-2010)". CDC. Retrieved 2024-04-24.
Many causesofautism, including environmental and genetic factors, have been recognized or proposed, but understanding of the theory of causation of autism...
heritability ofautism is the proportion of differences in expression ofautism that can be explained by genetic variation; if the heritability of a condition...
fraction ofautism cases may be traceable to genetic causes that are highly heritable but not inherited: that is, the mutation that causes the autism is not...
vaccines and autism has shown that there is no relationship between the two, causal or otherwise, and that vaccine ingredients do not causeautism. Vaccinologist...
Autism Speaks Inc. is an American non-profit autism awareness organization and the largest autism research organization in the United States. It sponsors...
autism was instead a complex and highly heritable disorder whose core aspects have distinct causes which often co-occur. The exact causesofautism are...
Syndromic autism represents about 25% of the total ASD cases. In most[quantify] cases, its etiology is known. Monogenic disorders are one of the causesof syndromic...
history ofautism spans over a century; autism has been subject to varying treatments, being pathologized or being viewed as a beneficial part of human...
ofautism is the study of the incidence and distribution ofautism spectrum disorders (ASD). A 2022 systematic review of global prevalence ofautism spectrum...
development of an animal model ofautism is one approach researchers use to study potential causesofautism. Given the complexity ofautism and its etiology...
Claims of a link between the MMR vaccine and autism have been extensively investigated and found to be false. The link was first suggested in the early...
promoting the incorrect claim that vaccination causesautism have asserted that the mercury in thiomersal is the cause. There is no scientific evidence to support...
The mechanisms ofautism are the molecular and cellular processes believed to cause or contribute to the symptoms ofautism. Multiple processes are hypothesized...
The autism rights movement, also known as the autistic acceptance movement, is a social movement allied with disability rights that emphasizes a neurodiversity...
Diagnoses ofautism have become more frequent since the 1980s, which has led to various controversies about both the causeofautism and the nature of the diagnoses...
pathophysiology ofautism is the study of the physiological processes that cause or are otherwise associated with autism spectrum disorders. Autism's symptoms...
known as Bettelheim's theory ofautism, is a largely abandoned psychological fringe theory that the causeofautism is a lack of parental, and in particular...
unsubstantiated hypothesis in evolutionary psychology regarding the causesofautism spectrum and schizophrenia spectrum disorders, first presented by Bernard...
aspects ofautism or sociology ofautism come into play with recognition ofautism, approaches to its support services and therapies, and how autism affects...
biomedical causesofautism spectrum conditions, to evaluate promising interventions for autistic people, and to improve the health and well-being of autistic...
The history ofautism in France is marked by the strong influence of psychoanalysis, and by the persistence of institutionalization practices that violate...
referred to as syndromic autism. ASD is associated with several genetic disorders, perhaps due to an overlap in genetic causes. Distinguishing between...
Autism therapies include a wide variety of therapies that help people with autism, or their families. Such methods of therapy seek to aid autistic people...
"awareness" of the condition and for independent research on the causesofautism. 2002 United Kingdom Autism Awareness Year The Autism Awareness Campaign of 2002...
claim that the passage of proteins through a "leaky" gut is the causeofautism. Evidence for claims that a leaky gut causesautism is weak and conflicting...
Autism is characterized by the early onset of impairments in reciprocal social interaction and communication and restricted repetitive behaviors or interests...
advocates the scientifically disproven view that autism and related disorders are primarily caused by environmental factors, particularly vaccines. The...
The diagnosis ofautism is based on a person's reported and directly observed behavior. There are no known biomarkers for autism spectrum conditions that...