Autistic& nonautistic groups did not differ in age of sexual activity onset or contraction of STIs; autistic males are uniquely more likely to be bisexual; autistic females are uniquely more likely to be homosexual

The sexual health, orientation, and activity of autistic adolescents and adults. Elizabeth Weir, Carrie Allison, Simon Baron-Cohen. Autism Research. September 18 2021. https://doi.org/10.1002/aur.2604

Abstract: Small studies suggest significant differences between autistic and nonautistic individuals regarding sexual orientation and behavior. We administered an anonymized, online survey to n = 2386 adults (n = 1183 autistic) aged 16–90 years to describe sexual activity, risk of sexually transmitted infections (STIs), and sexual orientation. Autistic individuals are less likely to report sexually activity or heterosexuality compared to nonautistic individuals, but more likely to self-report asexuality or an ‘other’ sexuality. Overall, autistic, and nonautistic groups did not differ in age of sexual activity onset or contraction of STIs. When evaluating sex differences, autistic males are uniquely more likely to be bisexual (compared to nonautistic males); conversely, autistic females are uniquely more likely to be homosexual (compared to nonautistic females). Thus, both autistic males and females may express a wider range of sexual orientations in different sex-specific patterns than general population peers. When comparing autistic males and females directly, females are more likely to have diverse sexual orientations (except for homosexuality) and engage in sexual activity, are less likely to identify as heterosexual, and have a lower mean age at which they first begin engaging in sexual activity. This is the largest study of sexual orientation of autistic adults. Sexual education and sexual health screenings of all children, adolescents, and adults (including autistic individuals) must remain priorities; healthcare professionals should use language that affirms a diversity of sexual orientations and supports autistic individuals who may have increased risks (affecting mental health, physical health, and healthcare quality) due to stress and discrimination from this intersectionality.

DISCUSSION

Autistic adolescents and adults may be less likely to engage in sexual activity than nonautistic individuals but may be more likely to have diverse sexual orientations; further, sex-specific patterns of sexual orientation and activity may be different between autistic and nonautistic adults. Overall, our results do not suggest differences in lifetime risk of STIs or age of sexual activity onset between autistic and nonautistic adolescents and adults. These findings may have important implications for the healthcare of autistic individuals, and in particular regarding sexual health screenings and support for mental health.

Our findings bolster previous evidence that autistic individuals identify with a wider range of sexual orientations than others (Bush, 2019; Bush et al., 2020; Dewinter et al., 2017; George & Stokes, 2018a; Pecora, Hancock, et al., 2020; Pecora, Hooley, et al., 2020; Rudolph et al., 2018). Our results clarify that autistic males are uniquely more likely to identify as bisexual than other males and autistic females are uniquely more likely to identify as homosexual than other females—suggesting that autistic adults do not conform to the same sex-specific patterns of sexual orientation observed in the general population. Autistic individuals are 8.1 and 7.6 times more likely to self-report identifying as asexual or ‘other’ sexual orientation than nonautistic individuals, respectively. These odds ratios are far higher than those previously reported in a large sample of individuals with high autistic traits (ORs: 1.7–3.1) (Rudolph et al., 2018), and in a smaller sample of autistic females (ORs: 2.3–2.4) (Pecora, Hooley, et al., 2020). These results align with previous findings in the field to confirm relatively greater likelihood of identifying as a nonheterosexual sexual orientation and relatively lower likelihood of identifying as heterosexual; however, future research should focus on replicating these findings in population-based samples of both autistic females and males to confirm actual odds of identifying with each sexual orientation and the sex differences therein.

Further, when comparing autistic females and males directly, our results suggest that autistic females tend to identify with a wider range of sexual orientations (except for homosexuality), are more likely to engage in sexual activity, and are more likely to do so initially at a relatively younger age. Further, our results confirm previous findings showing that the majority of both autistic males and females endorsed engaging in sexual activity (Bush, 2019; Dewinter et al., 2013; Sala et al., 2020), even if the relative proportion of individuals was smaller than nonautistic males and females (Bush, 2019; George & Stokes, 2018a).

Our results refute previous findings suggesting that autistic individuals have reduced risk of STIs compared to others (Fortuna et al., 2016; Schmidt et al., 2019), instead supporting that there is no significant difference in relative lifetime risk of STIs. While our age-stratified results suggest that younger autistic adults (aged 16–40 years) may be less likely to engage in sexual activity than younger nonautistic adults, this effect was eliminated after removing individuals who have not ever engaged in sexual activity from the analysis. It is also possible that our results differ from the two previous studies in this area for practical reasons: The first study only included a sample of 255 autistic adults which is unlikely to be demographically representative of all autistic adults (Fortuna et al., 2016) and the second study only considered STI risk among individuals with any intellectual or developmental disability, grouping together a highly heterogeneous sample of individuals with autism, cerebral palsy, down syndrome, spina bifida, intellectual disability, as well as those with fragile X, prader willi, and fetal alcohol syndrome (Schmidt et al., 2019). Thus, it is likely that previous studies have not accurately captured the sexual activity and behavior of sexually active autistic individuals specifically.

The results from our main analyses also support that risk of STIs may be partially mediated by high rates of asexuality and lack of ever engaging in sexual activity among autistic adults overall, as significance and odds ratios attenuated after accounting for these factors separately and additively. Although our study does not directly inquire about interest in sexual activity, our results confirm that asexuality may play a key role in reducing sexual activity among autistic individuals—and particularly among autistic females. The results from Adjusted Model 1 suggest that autistic females were 38% and autistic males were 22% as likely to report ever having engaged in sexual activity compared to sex-matched peers; however, the group differences decreased to autistic females being 48% and autistic males being 24% as likely to report ever having engaged in sexual activity compared to sex-matched peers in Adjusted Model 2, after accounting for self-reported asexuality among the participants. Interestingly, asexuality does not account for all of the variance between autistic and nonautistic females and males (respectively) regarding sexual activity. It is possible that this difference could be accounted for by reduced libido previously reported among autistic individuals (Bejerot & Erikson, 2014; Bush, 2019; Pecora et al., 2019), or that autistic adults' actual sexual activity may not meet their desire for it, due to differences with social communication, sensory sensitivities, or mental health conditions such as anxiety, which can often co-occur with autism (Croen et al., 2015; Hand et al., 2019). Taking into account reports of limited sexual knowledge/ education, low healthcare satisfaction, and high odds of unmet healthcare needs (Dewinter et al., 2013; Mason et al., 2019; Nicolaidis et al., 2013; Pecora, Hancock, et al., 2020), existing research may have underestimated true rates of STIs among autistic adults. Future research should focus on clarifying true lifetime prevalence rates of STIs among autistic and nonautistic adults comparatively.

Our age-stratified results also suggest that older autistic adults may be uniquely likely to identify as bisexual, whereas younger autistic adults may be uniquely likely to identify as homosexual compared to peers of similar age ranges (respectively). These findings provide some evidence that social norms (which change across time) may have affected individuals' acceptance of their specific sexual orientation; yet, our results support overall that autistic individuals of both age groups are more likely than others to identify with diverse sexual orientations and less likely to identify as heterosexual—which may be affected by social norms, biological differences, other factors, or a combination of these. Our findings do not support a difference in the mean age at which autistic and nonautistic adults report first engaging in sexual activity; however, Figure 1 above shows a relatively wider distribution among autistic adults, with a greater number of outliers on both sides. This is particularly concerning regarding sexual activity prior to the age of 13 years, which may relate to child sexual victimization; however, as our study did not define sexual activity specifically or ask about child sexual abuse, no definitive conclusions can be drawn from these findings at this time.

Our online, self-report, and cross-sectional methodology enabled recruitment of a large cohort of autistic adolescents and adults (aged 16–90 years; mean age approximately 41 years), providing the unique opportunity to describe the sexual health and orientation across the lifespan. This is the largest study of sexual orientation of autistic adolescents and adults and the first to consider asexuality and likelihood of ever engaging in sexual activity in measures of sexual health. This is also the first study that quantifies the odds of identifying with a particular sexual orientation, as well as the relative sex differences of those patterns while controlling for key demographic confounders, such as age, sex (where appropriate), ethnicity, education-level, and country of residence.

Limitations

Despite recruiting a large number of autistic individuals (particular older and female autistic individuals), the results presented are unlikely to represent the experiences of all autistic individuals. Our survey design and recruitment methods inherently exclude individuals without access to a computer and/or the internet, as well as those who are not physically or intellectually able to fill in a self-report survey. They also exclude non-English speakers, as the survey was only distributed in English; this is reflected in the demographics of our sample, as the vast majority of participants reported countries of residence with English as the native language (over 80% of the population resided in the United Kingdom, United States, or Australia). Further, white individuals, UK residents, and females were overrepresented in our sample; as such, our results may not be representative of all individuals. In particular, as attitudes toward sexual orientation and sexual activity may depend on norms within different languages, religions, and cultures, differences between our findings and past work in the area may simply reflect sampling biases (e.g., our study oversampled individuals from the UK and US whereas previous studies may have oversampled individuals from Europe and Australia). Additionally, our recruitment methods may have also biased our control group toward individuals with an interest in autism, including those who may have undiagnosed autism—underestimating true group differences between autistic and nonautistic adults; to minimize this risk, we excluded all individuals who suspect autism, are awaiting autism assessment, and/or self-diagnosed as autistic from both the autistic and nonautistic control groups.

There are also several other limitations of the study that should be considered. First, it is possible that the odds of identifying as a nonheterosexual orientation are greater among actually autistic individuals compared to those with high autistic traits; however, it is also possible that our study is underpowered to provide true effect size differences, and that the odds ratios represented here are artificially inflated due to “winner's curse” (a statistical phenomenon common to epidemiology and genetics where the effect size reported first is greater than the effect sizes reported in later studies of the same group) (Ioannidis, 2008). Second, our survey did not specifically define the terms “sexual activity”, “STIs”, or “sexual orientation”; however, our results largely align with several previous studies in these areas (Bush, 2019; Bush et al., 2020; Dewinter et al., 2017; George & Stokes, 2018a; Pecora, Hancock, et al., 2020; Pecora, Hooley, et al., 2020; Rudolph et al., 2018), and our results did not change when more strictly defining “STIs” in a sensitivity analysis. Third, sexual health and sexual activity are complex and attitudes toward them may change over time; this study cannot accurately describe all aspects of these multifaceted experiences. Fourth, the study relied on a self-report methodology on topics that may have been taboo or sensitive for some participants. For this reason, we explicitly told participants that the survey was anonymous and that all questions regarding sexual health were optional; however, we maintained high response rates even through this section (>99% for all questions related to sexual orientation and health). Still, it is possible that autistic individuals may have been more candid about their experiences than others due to differences in communication style and/or lessened concerns about adherence to social norms. Fifth, as we do not yet understand the factors that contribute to an individual's sexual orientation, the group differences observed regarding sexual orientation may correspond to these factors or to differences in acceptance of one's own sexuality (again, possibly due to differences in communication style/lessened adherence to social norms typical of autism).

Clinical implications

Currently, autistic individuals overall report lower satisfaction and self-efficacy within healthcare, as well as higher odds of unmet healthcare needs than others (Mason et al., 2019; Nicolaidis et al., 2013); and LGBTQA+ autistic individuals may be particularly vulnerable to worse mental and physical health, as well as inadequate healthcare (George & Stokes, 2018b; Hall et al., 2020; Pecora, Hooley, et al., 2020). Previous research that suggests that current sexual education of autistic individuals remains inadequate (Dewinter et al., 2013; Pecora, Hancock, et al., 2020), and that autistic females have self-reported lower rates of cervical cancer screenings (Nicolaidis et al., 2013). Our results also suggest that autistic adults are just as likely to contract STIs as others; further, other studies suggest that autistic females may be more likely to have gynecological and/or hormone-associated conditions (including polycystic ovarian syndrome) (Cherskov et al., 2018; Ruta et al., 2011), which can increase risk of diabetes, cardiovascular conditions, and cancers (Bhupathy et al., 2010; Brand et al., 2011; Cherskov et al., 2018; Mantovani & Fucic, 2014). Thus, improving sexual education and ensuring regular gynecological/ sexual health appointments for autistic adolescents and adults across the spectrum should remain a priority.

Healthcare professionals should be aware of increased risk of sexual victimization and abuse among autistic individuals across the lifespan (Brown-Lavoie et al., 2014; Pecora et al., 2019), and should take extra time and care to communicate effectively with autistic people when discussing relationships, sexual contact, and sexual health to ensure appropriate safeguarding; these risks may be particularly acute for autistic females and those with diverse sexual orientations (Pecora et al., 2019; Pecora, Hooley, et al., 2020). As challenges with social communication are a core feature of autism, practitioners providing these wellness checks (including sexual health screenings, as well as screenings for abuse during pediatric visits) may need extra time with autistic individuals and should focus on asking specific, rather than open-ended questions; further, practitioners should allow individuals to communicate in the way they feel most comfortable, including via written communication (Nicolaidis et al., 2015). Providers should also be aware that autistic individuals may be more likely to identify with a wider spectrum of genders and sexualities, and their language should be affirming and inclusive of all these identities, particularly when discussing sexual education, sexual health, and consent. Psychiatrists should also be aware of possible intersectionality between gender, sexual orientation, and/or disability, as their autistic patients may be particularly likely to experience mental or physical health problems due to discrimination and minority stress (George & Stokes, 2018b; Hall et al., 2020). Healthcare providers should work cooperatively with autistic and nonautistic individuals alike to communicate effectively and make plans to ensure that sexual relationships and sexual contact remain affirming, safe, and fulfilling.