Sex and gender differences in autism

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Sex and gender differences in autism exist regarding prevalence, presentation, and diagnosis.

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Men and boys are more frequently diagnosed with autism than women and girls. It is debated whether this is due to a sex difference in rates of autism spectrum disorders (ASD) or whether females are underdiagnosed. [1] [2] The prevalence ratio is often cited as about 4 males for every 1 female diagnosed. [3] Other research indicates that it is closer to 3:1 or 2:1. [2] [4] One in every 42 males and one in 189 females in the United States is diagnosed with autism spectrum disorder. [5] There is some evidence that females may also receive diagnoses somewhat later than males; however, thus far results have been contradictory. [6]

Several theories exist to explain the sex-based discrepancy, such as a genetic protective effect, [7] [8] [9] the extreme male brain theory [10] [11] [12] and phenotypic differences in the presentation between sexes, [9] [13] [14] [15] which may all be intertwined. Researchers have also debated whether a diagnostic gender bias has played a role in females being underdiagnosed with autism spectrum disorder. [16] Researchers have also speculated a gender bias in parental reporting due to the expectations and socialization of gender roles in society. [17]

Since autism is a largely genetic and hereditary condition, genetic factors that lead to differences depending on sex come into play, such as the role of androgen signaling in male development or X-linked mutations, whose associated genetic conditions are typically more common and severe in males. The extreme male brain theory suggests that autistic brains show an exaggeration of the features associated with male brains, such as increased size and decreased relative connectivity as well as systematic thinking over empathetic thinking. [18] The imprinted brain hypothesis suggests genomic imprinting is at least partly responsible for the sex differences in autism and points to the evidence for a common genetic cause with schizophrenia. [19] [20] [21]

Compared to men, women are generally required to be more impaired by their autism [22] or have more cognitive or behavioral conditions [23] than their male counterparts to meet autism spectrum criteria. There is evidence of increased incidence of social anxiety, [14] anorexia nervosa [24] [25] and self-harm in autistic females, [26] though the increased rates of anorexia nervosa and other eating disorders [27] may be due to confusion or conflation with avoidant/restrictive food intake disorder (ARFID), which is particularly common in autism. [28] Autistic girls and women show higher social motivation and a greater capacity for typical friendships than autistic boys and men, [29] [30] are less likely to be hyperactive, impulsive, have issues with conduct or stereotyped behavioral traits, [31] [32] and have been shown to mask their autistic behaviors and social difficulties more frequently than autistic men. [33] Autistic males often exhibit more easily observed behaviors at a younger age resulting in parental observance and subsequent evaluation of the child. In contrast, behavior of young females is more often overlooked, regardless of any associated at-risk factors [ broken anchor ] for ASD or other developmental delays. Ultimately, this may contribute to females more frequently receiving their ASD diagnosis later in life than their male counterpart. [34] There is a growing consensus among neuroscientists that the number of autistic women has been vastly underrepresented due to the assumption that it is primarily a male condition. [35]

Background

Hans Asperger was one of the first people to study autism, with all of his four study subjects being male. Another early researcher, Leo Kanner described "autistic disturbances of affective contact" in the group consisting of eight boys and three girls. [36]

Today, Autism Spectrum Disorder is commonly defined as a neurological developmental disorder with symptoms of poor social communication, repetitive behaviors, sensory sensitivities, executive dysfunction, and hyper-fixations. [37] In the modern day, women are less likely to be diagnosed as autistic than men; they are often misdiagnosed or not noticed to be neurodivergent by doctors. [38] Women are also more likely to be diagnosed as autistic at a later age than men. [39] This discrepancy in diagnoses is believed to be caused at least partially by camouflaging, a common autistic phenotype presented in females, which hides autistic traits. [40]

Theories explaining gender diagnosis disparity

Extreme male brain theory

Extreme male brain theory is an extension of the empathizing-systemizing theory, which categorizes people into 5 different groups based on their empathizing and systemizing expressions. In the general neurotypical population, females have a greater ability to empathize, and males have a greater ability to systemize. [41] Simon Baron-Cohen's extreme male brain theory states that autistic males have higher doses of prenatal testosterone and on average have a more systemizing brain, as opposed to the more empathizing female brain. He suggests that autistic brains show an exaggeration of the features associated with male brains. These are mainly size and connectivity, with males generally having a larger brain, [18] which is seen in an exaggerated form in those with ASD. Individuals with ASD were found to have widespread abnormalities in interconnectivity and general functioning in specific brain regions. [42] This could explain the different results on empathy tests between men and women [43] as well as the deficiencies in empathy seen in ASD, as empathy requires several brain regions to be activated which need information from many different areas of the brain. [44] Baron-Cohen therefore argues that genetic factors play a role in autism prevalence and that children with technically minded parents are more likely to be diagnosed with autism. [45] Although autistic females have been documented to have higher testosterone levels, which could support the Extreme Male Brain theory, not all autistic females show male-specific symptoms, leaving the Extreme Male Brain theory with Autism Spectrum Disorder to be controversial. [41]

Imprinted brain hypothesis

The imprinted brain theory suggests genomic imprinting is at least partly responsible for the sex differences in autism and implicates schizophrenia as well, claiming that genetic and physiological evidence suggests the two conditions are on a spectrum in which some mutations in certain genes cause lower social cognition but higher practical cognition (autism) while other mutations in the same genes cause lower practical cognition with higher social cognition (schizophrenia). [19] [20] [21]

Female protective effect hypothesis

According to the female protective effect hypothesis, more genetic mutations are required for a girl to develop autism than for a boy. In 2012, Harvard researchers published findings suggesting that, on average, more genetic and environmental risk factors are required for girls to develop autism, compared to boys. The researchers analyzed DNA samples of nearly 800 families affected by autism and nearly 16,000 individuals with a variety of neurodevelopmental disorders. They looked for various types of gene mutations. Overall, they found that females diagnosed with autism or another neurodevelopmental disorder had a greater number of harmful mutations throughout the genome than did males with the same disorders. [46] Women with an extra X chromosome, 47,XXX or triple X syndrome, have autism-like social impairments in 32% of cases. [47]

Hypothesis of female under-diagnosis

The prevalence ratio is often cited as about 4 males for every 1 female diagnosed. [3] Other research indicates that it closer to 3:1 or 2:1. [2] [48]

Some authors, clinicians and experts like Judith Gould, Tony Attwood, Lorna Wing and Christopher Gillberg [49] have proposed that autism in females may be underdiagnosed due to better natural superficial social mimicry skills in females, partially different set of symptoms and less knowledge about autism in females among experts. [50] In his preword to the book Asperger's and Girls, Attwood writes: "These tentative explanations for the apparent underrepresentation of girls with Asperger's Syndrome have yet to be examined by objective research studies." [51]

Specifically, Gould has discussed the idea that a pervasive developmental disorder called pathological demand avoidance, which is not officially included in diagnostic manuals, may offer a glimpse into how autism in females may present in some cases. [52] [53]

Another clinician, William Mandy, hypothesized referrals for ASD assessment are often started by teachers. Girls with ASD may sometimes lack the skills of social communication and this is not noticed until they are in a school setting. Therefore, girls suggested to have ASD may receive delayed or no clinical assessment. [54] Compared with males, females with autism are more likely to mask their restricted interests (strong or intense interests in specific topics or objects), which could decrease the chances of diagnosis. [55]

Female phenotype

Some have suggested a differential phenotype for autistic women; "a female-specific manifestation of autistic strengths and difficulties, which fits imperfectly with current, male-based conceptualisations" of autism. [48] Autistic women have been shown to score higher in self-reports of autistic masking, which may factor into the different phenotype. [56] One study found evidence for a diagnostic bias against girls who meet criteria for ASD. In some cases where females showed severe autistic traits, they failed to meet the criteria for a diagnosis, because of the lack of sensitivity to the female phenotype. [55]

Camouflaging

The DSM-5 mainly looks at two categories of autism spectrum symptoms when diagnosing someone: social deficits and restricted/repetitive behaviors and interests. Both of these categories of symptoms can be hidden by an aspect of the autistic female phenotype known as camouflaging. [57] [40] [58]

Autistic girls tend to camouflage more than boys, this leads to many of their symptoms being hidden and not noticed by professionals. [40] When it comes to social camouflaging, there are three sub-categories according to the Camouflaging Autistic Traits Questionnaire (CAT-Q): Masking, Assimilation, and Compensation. [59] Masking is the act of constantly monitoring one's behavior in order to hide one's autistic traits and/or putting on a fake persona. [57] [59] Assimilation is known as "hiding in plain sight" or trying to blend in with non-autistic peers. [57] Finally, compensation is trying to over-compensate for a lack of social abilities. Examples of this can include mimicking real or fictional people, over exaggerating non-verbal expressions, and creating scripts or rules when having a conversion with someone. [57]

Camouflaging can also be used to hide repetitive/restricted behaviors and interests. [57] In fact, researchers have found that autistic girls are ten times more likely to not originally meet the DSM-5 criteria for restricted/repetitive behaviors. [60] Sensory overstimulation is another autistic trait that can be hidden by masking. [57] Participants of the Hull, et al., would internalize their overwhelming feelings and try to channel it through small and unnoticeable everyday objects. If those objects were not enough to calm them down, then they would try to leave the environment and recuperate by making " regular excuses'' as to why they needed to leave. [57]

Downfalls of camouflaging

Studies have shown that high levels of camouflaging is can lead to higher levels of anxiety and depression and can increase the risk of suicidal ideation. [61] [48] [62] [40] Studies have also found that camouflaging can lead to a skewed sense of self. [48] This is especially the case for people who had been masking and mimicking other people for long periods of time. [57] Another factor of masking is mental and physical exhaustion after a camouflaging session. [40] According to the participants of the Hull, et al (2017) [57] study, the longer that autistic individuals camouflage, the worse the exhaustion becomes and the longer these individuals need to rest and recharge. This study had also found that there were increased amounts of anxiety and stress revolving around camouflaging because the participants were often worried that they did not mask enough, did not mask correctly, or did not reach the desired effects of masking in that camouflaging session. Another one of the factors that increased anxiety and exhaustion while camouflaging is the fact that it "involved a constant monitoring of the situation, as if training oneself in self-monitoring, self-awareness, and monitoring others' reactions, both during and after the interaction occurred." [57]

Differences in gender and sexuality identification

Sexuality is often discussed within the autistic community, with many observations that identities other than cis-hetero seem to be more common than is observed in the neurotypical population. There have not been many formal studies on this to date, however members[ who? ] of the community speculate that autistic individuals generally have different ideals, perceptions and desires than neurotypicals or simply do not comprehend or agree with society's expectation, making them more apt to diverge from the norm.

A study looking at the co-occurrence of ASD in patients with gender dysphoria found 7.8% of patients to be on the autism spectrum. [63] Another study consisting of online surveys that included those who identified as nonbinary and those identifying as transgender without diagnoses of gender dysphoria found the number to be as high as 24% of gender diverse people having autism, versus around 5% of the surveyed cisgender people. [64] A possible hypothesis for the correlation may be that autistic people are less willing or able to conform to societal norms, which may explain the high number of autistic individuals who identify outside the stereotypical gender binary. [65] As of yet, there have been no studies specifically addressing the occurrence of autism in intersex individuals.

A study conducted by Byers and Nichols (2014) explored the level of sexual satisfaction of high-functioning autistic individuals, with researchers testing the sexual and relationship satisfaction of neurotypical versus high functioning autistic individuals. The results suggest that men with ASD are generally less satisfied with their relationship or marriage compared to neurotypical men and women, and women with ASD. [66]

See also

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References

  1. Halladay, Alycia K; Bishop, Somer; Constantino, John N; Daniels, Amy M; Koenig, Katheen; Palmer, Kate; Messinger, Daniel; Pelphrey, Kevin; Sanders, Stephan J; Singer, Alison Tepper; Taylor, Julie Lounds; Szatmari, Peter (December 2015). "Sex and gender differences in autism spectrum disorder: summarizing evidence gaps and identifying emerging areas of priority". Molecular Autism. 6 (1): 36. doi: 10.1186/s13229-015-0019-y . PMC   4465158 . PMID   26075049.
  2. 1 2 3 Loomes, Rachel; Hull, Laura; Mandy, William Polmear Locke (June 2017). "What Is the Male-to-Female Ratio in Autism Spectrum Disorder? A Systematic Review and Meta-Analysis". Journal of the American Academy of Child & Adolescent Psychiatry. 56 (6): 466–474. doi:10.1016/j.jaac.2017.03.013. PMID   28545751. S2CID   20420861.
  3. 1 2 Fombonne, Eric (June 2009). "Epidemiology of Pervasive Developmental Disorders". Pediatric Research. 65 (6): 591–598. doi: 10.1203/PDR.0b013e31819e7203 . PMID   19218885. S2CID   20373463.
  4. Hull, Laura; Petrides, K. V.; Mandy, William (December 2020). "The Female Autism Phenotype and Camouflaging: a Narrative Review". Review Journal of Autism and Developmental Disorders. 7 (4): 306–317. doi: 10.1007/s40489-020-00197-9 . S2CID   214314845.
  5. "Data and Statistics on Autism Spectrum Disorder". Centers for Disease Control and Prevention. 25 September 2020.
  6. Begeer, Sander; Mandell, David; Wijnker-Holmes, Bernadette; Venderbosch, Stance; Rem, Dorien; Stekelenburg, Fred; Koot, Hans M. (May 2013). "Sex Differences in the Timing of Identification Among Children and Adults with Autism Spectrum Disorders". Journal of Autism and Developmental Disorders. 43 (5): 1151–1156. doi:10.1007/s10803-012-1656-z. PMID   23001766. S2CID   2705562.
  7. Gockley, Jake; Willsey, A Jeremy; Dong, Shan; Dougherty, Joseph D; Constantino, John N; Sanders, Stephan J (December 2015). "The female protective effect in autism spectrum disorder is not mediated by a single genetic locus". Molecular Autism. 6 (1): 25. doi: 10.1186/s13229-015-0014-3 . PMC   4429476 . PMID   25973162.
  8. Robinson, E. B.; Lichtenstein, P.; Anckarsater, H.; Happe, F.; Ronald, A. (26 March 2013). "Examining and interpreting the female protective effect against autistic behavior". Proceedings of the National Academy of Sciences. 110 (13): 5258–5262. Bibcode:2013PNAS..110.5258R. doi: 10.1073/pnas.1211070110 . PMC   3612665 . PMID   23431162.
  9. 1 2 Lai, Meng-Chuan; Baron-Cohen, Simon; Buxbaum, Joseph D (December 2015). "Understanding autism in the light of sex/gender". Molecular Autism. 6 (1): 24. doi: 10.1186/s13229-015-0021-4 . PMC   4429357 . PMID   25973161.
  10. Baron-Cohen, Simon (June 2002). "The extreme male brain theory of autism". Trends in Cognitive Sciences. 6 (6): 248–254. doi:10.1016/S1364-6613(02)01904-6. PMID   12039606. S2CID   8098723.
  11. Lai, Meng-Chuan; Lombardo, Michael V.; Pasco, Greg; Ruigrok, Amber N. V.; Wheelwright, Sally J.; Sadek, Susan A.; Chakrabarti, Bhismadev; Baron-Cohen, Simon (13 June 2011). "A Behavioral Comparison of Male and Female Adults with High Functioning Autism Spectrum Conditions". PLOS ONE. 6 (6): e20835. Bibcode:2011PLoSO...620835L. doi: 10.1371/journal.pone.0020835 . PMC   3113855 . PMID   21695147.
  12. van Eijk, Liza; Zietsch, Brendan P. (August 2021). "Testing the extreme male brain hypothesis: Is autism spectrum disorder associated with a more male-typical brain?". Autism Research. 14 (8): 1597–1608. doi:10.1002/aur.2537. ISSN   1939-3792. PMC   8328919 . PMID   34008924.
  13. Lai, Meng-Chuan; Lombardo, Michael V.; Ruigrok, Amber N. V.; Chakrabarti, Bhismadev; Wheelwright, Sally J.; Auyeung, Bonnie; Allison, Carrie; Baron-Cohen, Simon (17 October 2012). "Cognition in Males and Females with Autism: Similarities and Differences". PLOS ONE. 7 (10): e47198. Bibcode:2012PLoSO...747198L. doi: 10.1371/journal.pone.0047198 . PMC   3474800 . PMID   23094036.
  14. 1 2 Ludlow, Amanda K.; Roberts, Hannah; Gutierrez, Roberto (1 April 2015). "Social Anxiety and Response to Touch: A Preliminary Exploration of Broader Autism Phenotype in Females". SAGE Open. 5 (2): 215824401558085. doi:10.1177/2158244015580854. hdl: 2299/16551 . S2CID   14324454.
  15. Torres, Elizabeth B.; Isenhower, Robert W.; Yanovich, Polina; Rehrig, Gwendolyn; Stigler, Kimberly; Nurnberger, John; José, Jorge V. (1 October 2013). "Strategies to develop putative biomarkers to characterize the female phenotype with autism spectrum disorders". Journal of Neurophysiology. 110 (7): 1646–1662. doi:10.1152/jn.00059.2013. PMID   23864377.
  16. Supekar, Kaustubh; Menon, Vinod (2015-09-04). "Sex differences in structural organization of motor systems and their dissociable links with repetitive/restricted behaviors in children with autism". Molecular Autism. 6 (1): 50. doi: 10.1186/s13229-015-0042-z . PMC   4559968 . PMID   26347127.
  17. Holtmann, Martin; Bölte, Sven; Poustka, Fritz (2007). "Autism spectrum disorders: sex differences in autistic behaviour domains and coexisting psychopathology". Developmental Medicine & Child Neurology. 49 (5): 361–366. doi: 10.1111/j.1469-8749.2007.00361.x . PMID   17489810.
  18. 1 2 Baron-Cohen, Simon; Knickmeyer, Rebecca C.; Belmonte, Matthew K. (4 November 2005). "Sex Differences in the Brain: Implications for Explaining Autism" (PDF). Science. 310 (5749): 819–823. Bibcode:2005Sci...310..819B. doi:10.1126/science.1115455. PMID   16272115. S2CID   44330420.
  19. 1 2 Crespi, Bernard; Badcock, Christopher (June 2008). "Psychosis and autism as diametrical disorders of the social brain" (PDF). Behavioral and Brain Sciences. 31 (3): 241–261. doi:10.1017/S0140525X08004214. PMID   18578904.
  20. 1 2 Crespi, Bernard; Stead, Philip; Elliot, Michael (26 January 2010). "Comparative genomics of autism and schizophrenia". Proceedings of the National Academy of Sciences of the United States of America. 107 (Suppl 1): 1736–1741. doi: 10.1073/pnas.0906080106 . PMC   2868282 . PMID   19955444.
  21. 1 2 Ciaramidaro, Angela; Bölte, Sven; Schlitt, Sabine; Hainz, Daniela; Poustka, Fritz; Weber, Bernhard; Bara, Bruno G; Freitag, Christine; Walter, Henrik (1 January 2015). "Schizophrenia and Autism as Contrasting Minds: Neural Evidence for the Hypo-Hyper-Intentionality Hypothesis". Schizophrenia Bulletin. 41 (1): 171–179. doi:10.1093/schbul/sbu124. PMC   4266299 . PMID   25210055.
  22. Russell, Ginny; Ford, Tamsin; Steer, Colin; Golding, Jean (2010). "Identification of children with the same level of impairment as children on the autistic spectrum, and analysis of their service use". Journal of Child Psychology and Psychiatry. 51 (6): 643–651. doi:10.1111/j.1469-7610.2010.02233.x. PMID   20345841.
  23. Dworzynski, Katharina; Ronald, Angelica; Bolton, Patrick; Happé, Francesca (1 August 2012). "How Different Are Girls and Boys Above and Below the Diagnostic Threshold for Autism Spectrum Disorders?". Journal of the American Academy of Child & Adolescent Psychiatry. 51 (8): 788–797. doi:10.1016/j.jaac.2012.05.018. PMID   22840550.
  24. Baron-Cohen, Simon; Jaffa, Tony; Davies, Sarah; Auyeung, Bonnie; Allison, Carrie; Wheelwright, Sally (December 2013). "Do girls with anorexia nervosa have elevated autistic traits?". Molecular Autism. 4 (1): 24. doi: 10.1186/2040-2392-4-24 . PMC   3735388 . PMID   23915495.
  25. Rhind, Charlotte; Bonfioli, Elena; Hibbs, Rebecca; Goddard, Elizabeth; Macdonald, Pamela; Gowers, Simon; Schmidt, Ulrike; Tchanturia, Kate; Micali, Nadia; Treasure, Janet (2014). "An examination of autism spectrum traits in adolescents with anorexia nervosa and their parents". Molecular Autism. 5 (1): 56. doi: 10.1186/2040-2392-5-56 . PMC   4280745 . PMID   25553237.
  26. Cohen, Ira L.; Tsiouris, John A.; Flory, Michael J.; Kim, Soh-Yule; Freedland, Robert; Heaney, Glenn; Pettinger, Jill; Ted Brown, W. (May 2010). "A Large Scale Study of the Psychometric Characteristics of the IBR Modified Overt Aggression Scale: Findings and Evidence for Increased Self-Destructive Behaviors in Adult Females with Autism Spectrum Disorder". Journal of Autism and Developmental Disorders. 40 (5): 599–609. doi:10.1007/s10803-009-0908-z. PMID   19941156. S2CID   23789973.
  27. Huke, Vanessa; Turk, Jeremy; Saeidi, Saeideh; Kent, Andy; Morgan, John F. (2013). "Autism Spectrum Disorders in Eating Disorder Populations: A Systematic Review". European Eating Disorders Review. 21 (5): 345–351. doi:10.1002/erv.2244. PMID   23900859.
  28. Shea, Elizabeth (24 May 2016). "Eating disorder or disordered eating? Eating patterns in autism". The National Autistic Society.
  29. Head, Alexandra M.; McGillivray, Jane A.; Stokes, Mark A. (28 February 2014). "Gender differences in emotionality and sociability in children with autism spectrum disorders". Molecular Autism. 5 (1): 19. doi: 10.1186/2040-2392-5-19 . PMC   3945617 . PMID   24576331.
  30. Sedgewick, Felicity; Hill, Vivian; Yates, Rhiannon; Pickering, Leanne; Pellicano, Elizabeth (1 April 2016). "Gender Differences in the Social Motivation and Friendship Experiences of Autistic and Non-autistic Adolescents". Journal of Autism and Developmental Disorders. 46 (4): 1297–1306. doi:10.1007/s10803-015-2669-1. PMC   4786616 . PMID   26695137.
  31. Mandy, William; Chilvers, Rebecca; Chowdhury, Uttom; Salter, Gemma; Seigal, Anna; Skuse, David (1 July 2012). "Sex Differences in Autism Spectrum Disorder: Evidence from a Large Sample of Children and Adolescents". Journal of Autism and Developmental Disorders. 42 (7): 1304–1313. doi:10.1007/s10803-011-1356-0. PMID   21947663. S2CID   18639019.
  32. Van Wijngaarden-Cremers, Patricia J. M.; van Eeten, Evelien; Groen, Wouter B.; Van Deurzen, Patricia A.; Oosterling, Iris J.; Van der Gaag, Rutger Jan (March 2014). "Gender and age differences in the core triad of impairments in autism spectrum disorders: a systematic review and meta-analysis". Journal of Autism and Developmental Disorders. 44 (3): 627–635. doi:10.1007/s10803-013-1913-9. PMID   23989936. S2CID   1705914.
  33. Schuck, Rachel K.; Flores, Ryan E.; Fung, Lawrence K. (June 2019). "Brief Report: Sex/Gender Differences in Symptomology and Camouflaging in Adults with Autism Spectrum Disorder". Journal of Autism and Developmental Disorders. 49 (6): 2597–2604. doi:10.1007/s10803-019-03998-y. PMC   6753236 . PMID   30945091.
  34. Ramsey, Riane K.; Nichols, Lashae; Ludwig, Natasha N.; Fein, Deborah; Adamson, Lauren B.; Robins, Diana L. (2018-12-01). "Brief Report: Sex Differences in Parental Concerns for Toddlers with Autism Risk". Journal of Autism and Developmental Disorders. 48 (12): 4063–4069. doi:10.1007/s10803-018-3583-0. ISSN   1573-3432. PMC   6203663 . PMID   29700708.
  35. Devlin, Hannah (14 September 2018). "Thousands of autistic girls and women 'going undiagnosed' due to gender bias". The Guardian. Retrieved 13 September 2021.
  36. Kanner, Leo (1943). "Autistic disturbances of affective contact". Nervous Child. 2 (3): 217–250. NAID   10007611258.
  37. Jung, Minyoung; Mody, Maria; Saito, Daisuke N.; Tomoda, Akemi; Okazawa, Hidehiko; Wada, Yuji; Kosaka, Hirotaka (2015-11-24). "Sex Differences in the Default Mode Network with Regard to Autism Spectrum Traits: A Resting State fMRI Study". PLOS ONE. 10 (11): e0143126. Bibcode:2015PLoSO..1043126J. doi: 10.1371/journal.pone.0143126 . ISSN   1932-6203. PMC   4658035 . PMID   26600385.
  38. Lai, Meng-Chuan; Baron-Cohen, Simon (November 2015). "Identifying the lost generation of adults with autism spectrum conditions". The Lancet Psychiatry. 2 (11): 1013–1027. doi:10.1016/s2215-0366(15)00277-1. PMID   26544750.
  39. Giarelli, Ellen; Wiggins, Lisa D.; Rice, Catherine E.; Levy, Susan E.; Kirby, Russell S.; Pinto-Martin, Jennifer; Mandell, David (1 April 2010). "Sex differences in the evaluation and diagnosis of autism spectrum disorders among children". Disability and Health Journal. 3 (2): 107–116. doi:10.1016/j.dhjo.2009.07.001. PMC   4767258 . PMID   21122776.
  40. 1 2 3 4 5 Lai, Meng-Chuan; Lombardo, Michael V; Ruigrok, Amber NV; Chakrabarti, Bhismadev; Auyeung, Bonnie; Szatmari, Peter; Happé, Francesca; Baron-Cohen, Simon; MRC AIMS Consortium (August 2017). "Quantifying and exploring camouflaging in men and women with autism". Autism. 21 (6): 690–702. doi:10.1177/1362361316671012. ISSN   1362-3613. PMC   5536256 . PMID   27899710.
  41. 1 2 Williams, Olivia O. F.; Coppolino, Madeleine; Perreault, Melissa L. (2021-12-09). "Sex differences in neuronal systems function and behaviour: beyond a single diagnosis in autism spectrum disorders". Translational Psychiatry. 11 (1): 625. doi:10.1038/s41398-021-01757-1. ISSN   2158-3188. PMC   8660826 . PMID   34887388.
  42. Anderson, J. S.; Druzgal, T. J.; Froehlich, A.; DuBray, M. B.; Lange, N.; Alexander, A. L.; Abildskov, T.; Nielsen, J. A.; Cariello, A. N.; Cooperrider, J. R.; Bigler, E. D.; Lainhart, J. E. (2010-10-12). "Decreased Interhemispheric Functional Connectivity in Autism". Cerebral Cortex. 21 (5): 1134–1146. doi:10.1093/cercor/bhq190. ISSN   1047-3211. PMC   3077433 . PMID   20943668.
  43. Teatero, Missy L.; Netley, Charles (November 2013). "A Critical Review of the Research on the Extreme Male Brain Theory and Digit Ratio (2D:4D)". Journal of Autism and Developmental Disorders. 43 (11): 2664–2676. doi:10.1007/s10803-013-1819-6. ISSN   0162-3257. PMID   23575643. S2CID   254569210.
  44. Baron-Cohen, Simon; Knickmeyer, Rebecca C.; Belmonte, Matthew K. (2005-11-04). "Sex Differences in the Brain: Implications for Explaining Autism" (PDF). Science. 310 (5749): 819–823. Bibcode:2005Sci...310..819B. doi:10.1126/science.1115455. ISSN   0036-8075. PMID   16272115. S2CID   44330420.
  45. Baron-Cohen, Simon (November 2012). "Autism and the technical mind: live chat with Simon Baron-Cohen, November 9, 10 A.M. EST". Scientific American . Vol. 307, no. 5. pp. 72–75.
  46. Jacquemont, Sébastien; Coe, Bradley P.; Hersch, Micha; Duyzend, Michael H.; Krumm, Niklas; Bergmann, Sven; Beckmann, Jacques S.; Rosenfeld, Jill A.; Eichler, Evan E. (6 March 2014). "A Higher Mutational Burden in Females Supports a "Female Protective Model" in Neurodevelopmental Disorders". The American Journal of Human Genetics. 94 (3): 415–425. doi:10.1016/j.ajhg.2014.02.001. PMC   3951938 . PMID   24581740.
  47. Otter, Maarten; Crins, Peter M. L.; Campforts, Bea C. M.; Stumpel, Constance T. R. M.; van Amelsvoort, Thérèse A. M. J.; Vingerhoets, Claudia (March 2021). "Social functioning and emotion recognition in adults with triple X syndrome". BJPsych Open. 7 (2): e51. doi:10.1192/bjo.2021.8. PMC   8058878 . PMID   33583482.
  48. 1 2 3 4 Bargiela, Sarah; Steward, Robyn; Mandy, William (1 October 2016). "The Experiences of Late-diagnosed Women with Autism Spectrum Conditions: An Investigation of the Female Autism Phenotype". Journal of Autism and Developmental Disorders. 46 (10): 3281–3294. doi:10.1007/s10803-016-2872-8. PMC   5040731 . PMID   27457364.
  49. "Gender and autism". The National Autistic Society. Retrieved 2016-06-01.
  50. Attwood, Tony (2006). Asperger's and Girls. London: Jessica Kingsley Publishers. pp. 2–6. ISBN   978-1-932565-40-9.
  51. Attwood, Tony (2006). Asperger's and Girls. London: Jessica Kingsley Publishers. p. 6. ISBN   978-1-932565-40-9.
  52. "Missed Diagnosis or Misdiagnosis? Women and Girls with PDA" (PDF). Dr Judith Gould, Dr Jacqui Ashton Smith. Archived from the original (PDF) on 2016-10-13. Retrieved 2016-01-06.
  53. Gould, Judith; Ashton-Smith, Jacqui (31 May 2011). "Missed diagnosis or misdiagnosis? Girls and women on the autism spectrum". Good Autism Practice. 12 (1): 34–41.
  54. Mandy, William; Chilvers, Rebecca; Chowdhury, Uttom; Salter, Gemma; Seigal, Anna; Skuse, David (2012-07-01). "Sex Differences in Autism Spectrum Disorder: Evidence from a Large Sample of Children and Adolescents". Journal of Autism and Developmental Disorders. 42 (7): 1304–1313. doi:10.1007/s10803-011-1356-0. ISSN   1573-3432. PMID   21947663. S2CID   18639019.
  55. 1 2 Loomes, Rachel; Hull, Laura; Mandy, William Polmear Locke (June 2017). "What Is the Male-to-Female Ratio in Autism Spectrum Disorder? A Systematic Review and Meta-Analysis" (PDF). Journal of the American Academy of Child & Adolescent Psychiatry. 56 (6): 466–474. doi:10.1016/j.jaac.2017.03.013. PMID   28545751. S2CID   20420861.
  56. Hull, L; Lai, MC; Baron-Cohen, S; Allison, C; Smith, P; Petrides, KV; Mandy, W (February 2020). "Gender differences in self-reported camouflaging in autistic and non-autistic adults" (PDF). Autism: The International Journal of Research and Practice. 24 (2): 352–363. doi:10.1177/1362361319864804. PMID   31319684. S2CID   197664299 . Retrieved 25 October 2021.
  57. 1 2 3 4 5 6 7 8 9 10 Hull, Laura; Petrides, K. V.; Allison, Carrie; Smith, Paula; Baron-Cohen, Simon; Lai, Meng-Chuan; Mandy, William (2017-08-01). ""Putting on My Best Normal": Social Camouflaging in Adults with Autism Spectrum Conditions". Journal of Autism and Developmental Disorders. 47 (8): 2519–2534. doi:10.1007/s10803-017-3166-5. ISSN   1573-3432. PMC   5509825 . PMID   28527095.
  58. Jorgenson, Courtney; Lewis, Timothy; Rose, Chad; Kanne, Stephen (December 2020). "Social Camouflaging in Autistic and Neurotypical Adolescents: A Pilot Study of Differences by Sex and Diagnosis". Journal of Autism and Developmental Disorders. 50 (12): 4344–4355. doi:10.1007/s10803-020-04491-7. ISSN   0162-3257. PMID   32270386. S2CID   215617283.
  59. 1 2 Engelbrecht, Natalie. "The Camouflaging Autistic Traits Questionnaire (CAT-Q) | Embrace Autism". embrace-autism.com. Retrieved 2023-10-12.
  60. Hiller, Rachel M.; Young, Robyn L.; Weber, Nathan (2014). "Sex Differences in Autism Spectrum Disorder based on DSM-5 Criteria: Evidence from Clinician and Teacher Reporting" (PDF). Journal of Abnormal Child Psychology. 42 (8): 1381–1393. doi:10.1007/s10802-014-9881-x. PMID   24882502. S2CID   254580713 . Retrieved 2022-12-04.
  61. Cassidy, S. A.; Gould, K.; Townsend, E.; Pelton, M.; Robertson, A. E.; Rodgers, J. (2020-10-01). "Is Camouflaging Autistic Traits Associated with Suicidal Thoughts and Behaviours? Expanding the Interpersonal Psychological Theory of Suicide in an Undergraduate Student Sample". Journal of Autism and Developmental Disorders. 50 (10): 3638–3648. doi:10.1007/s10803-019-04323-3. ISSN   1573-3432. PMC   7502035 . PMID   31820344.
  62. Cage, Eilidh; Troxell-Whitman, Zoe (2019-05-01). "Understanding the Reasons, Contexts and Costs of Camouflaging for Autistic Adults". Journal of Autism and Developmental Disorders. 49 (5): 1899–1911. doi:10.1007/s10803-018-03878-x. ISSN   1573-3432. PMC   6483965 . PMID   30627892.
  63. de Vries, Annelou L. C.; Noens, Ilse L. J.; Cohen-Kettenis, Peggy T.; van Berckelaer-Onnes, Ina A.; Doreleijers, Theo A. (August 2010). "Autism Spectrum Disorders in Gender Dysphoric Children and Adolescents". Journal of Autism and Developmental Disorders. 40 (8): 930–936. doi:10.1007/s10803-010-0935-9. PMC   2904453 . PMID   20094764.
  64. Dattaro, Laura (2020-09-14). "Largest study to date confirms overlap between autism and gender diversity". Spectrum. Retrieved 5 May 2021.
  65. Warrier, Varun; Greenberg, David; Weir, Elizabeth; Buckingham, Clara; Smith, Paula; Lai, Meng-Chuan; Allison, Carrie; Baron-Cohen, Simon (2020-08-07). "Elevated rates of autism, other neurodevelopmental and psychiatric diagnoses, and autistic traits in transgender and gender-diverse individuals". Nature Communications. 11 (3959): 3959. Bibcode:2020NatCo..11.3959W. doi:10.1038/s41467-020-17794-1. PMC   7415151 . PMID   32770077.
  66. Byers, E. Sandra; Nichols, Shana (September 2014). "Sexual Satisfaction of High-Functioning Adults with Autism Spectrum Disorder". Sexuality and Disability. 32 (3): 365–382. doi:10.1007/s11195-014-9351-y. S2CID   143453860.

Further reading