Transgender and gender-diverse adults are three to six times more likely as cisgender adults (individuals whose gender identity corresponds to their sex assigned at birth) to be diagnosed as autistic, according to a new study by scientists at the University of Cambridge’s Autism Research Centre.

Both autistic individuals and transgender and gender-diverse individuals are marginalized and experience multiple vulnerabilities. It is important that we safe-guard the rights of these individuals to be themselves, receive the requisite support, and enjoy equality and celebration of their differences, free of societal stigma or discriminationSimon Baron Cohen

This research, conducted using data from over 600,000 adult individuals, confirms previous smaller scale studies from clinics. The results are published today in Nature Communications.

A better understanding of gender diversity in autistic individuals will help provide better access to health care and post-diagnostic support for autistic transgender and gender-diverse individuals.

The team used five different datasets, including a dataset of over 500,000 individuals collected as a part of the Channel 4 documentary “Are you autistic?”. In these datasets, participants had provided information about their gender identity, and if they received a diagnosis of autism or other psychiatric conditions such as depression or schizophrenia. Participants also completed a measure of autistic traits.

Strikingly, across all five datasets, the team found that transgender and gender-diverse adult individuals were between three and six times more likely to indicate that they were diagnosed as autistic compared to cisgender individuals. While the study used data from adults who indicated that they had received an autism diagnosis, it is likely that many individuals on the autistic spectrum may be undiagnosed. As around 1.1% of the UK population is estimated to be on the autistic spectrum, this result would suggest that somewhere between 3.5.-6.5% of transgender and gender-diverse adults is on the autistic spectrum.

Dr Meng-Chuan Lai, a collaborator on the study at the University of Toronto, said: “We are beginning to learn more about how the presentation of autism differs in cisgender men and women. Understanding how autism manifests in transgender and gender-diverse people will enrich our knowledge about autism in relation to gender and sex. This enables clinicians to better recognize autism and provide personalised support and health care.”

Transgender and gender-diverse individuals were also more likely to indicate that they had received diagnoses of mental health conditions, particularly depression, which they were more than twice as likely as their cisgender counterparts to have experienced. Transgender and gender-diverse individuals also, on average, scored higher on measures of autistic traits compared to cisgender individuals, regardless of whether they had an autism diagnosis.

Dr Varun Warrier, who led the study, said: “This finding, using large datasets, confirms that the co-occurrence between being autistic and being transgender and gender-diverse is robust. We now need to understand the significance of this co-occurrence, and identify and address the factors that contribute to well-being of this group of people.”

The study investigates the co-occurrence between gender identity and autism. The team did not investigate if one causes the other.

Professor Simon Baron-Cohen, Director of the Autism Research Centre at Cambridge, and a member of the team, said: “Both autistic individuals and transgender and gender-diverse individuals are marginalized and experience multiple vulnerabilities. It is important that we safe-guard the rights of these individuals to be themselves, receive the requisite support, and enjoy equality and celebration of their differences, free of societal stigma or discrimination.”

Dr Warrier is a Research Fellow at St Catharine’s College and Professor Baron Cohen is a Fellow at Trinity College.

This study was supported by the Autism Research Trust, the Medical Research Council, the Wellcome Trust, and the Templeton World Charity Foundation., Inc. It was conducted in association with the NIHR CLAHRC for Cambridgeshire and Peterborough NHS Foundation Trust, and the NIHR Cambridge Biomedical Research Centre.

New research from the University of Cambridge suggests that autistic individuals are less likely to identify as heterosexual and more likely to identify with a diverse range of sexual orientations than non-autistic individuals.

The findings have important implications for the healthcare and support of autistic individuals. The results are published in the journal Autism Research.  

For many years it was wrongly assumed that autistic individuals are uninterested in sexual or romantic relationships, but this is not the case. In recent years, small studies have suggested that autistic individuals are more likely to experience a wider diversity of sexual orientations and are less likely to have sexually transmitted infections (STIs). However, the existing evidence has been limited in size and scope.

In the largest study to date on these topics, the team at the Autism Research Centre used an anonymous, self-report survey to study the sexual activity, sexual orientation, and sexual health of autistic adults. Overall, 1,183 autistic and 1,203 non-autistic adolescents and adults (aged 16-90 years) provided information about their sexual activity, sexual orientation, and medical history of STIs.

The results showed that the majority of autistic adults (70% of autistic males and 76% of autistic females) engage in sexual activity—although they do so to a lesser degree than their non-autistic peers (89% of both non-autistic males and females report engaging in sexual activity). In contrast to previous findings, the results also found that there were no differences in likelihood of ever contracting an STI, or the age at which participants first engaged in sexual activity, between autistic and non-autistic individuals.

In addition, the study found that autistic adults and adolescents are approximately eight times more likely to identify as asexual and ‘other’ sexuality than their non-autistic peers. And there were sex differences in sexual orientation: autistic males are 3.5 times more likely to identify as bisexual than non-autistic males, whereas autistic females are three times more likely to identify as homosexual than non-autistic females.

When comparing autistic females and males directly, autistic females were more likely to be sexually active; more likely to identify as asexual, bisexual, and ‘other’ sexuality; and were less likely to identify as heterosexual.

Elizabeth Weir, a PhD candidate at the Autism Research Centre in Cambridge, and the lead researcher of the study, said: “Understanding the intersectional identities of autistic individuals who are asexual, bisexual, homosexual, or ‘other’ sexuality is key. It is particularly important that healthcare providers and educators use language that is affirming and accepting of all sexual orientations and gender identities when providing sexual education and sexual health screening checks to autistic and non-autistic people alike.” 

Dr Carrie Allison, Director of Strategy at the Autism Research Centre and a member of the team, said: “We must ensure that autistic individuals are receiving equal access to healthcare and support in their choices in their personal lives, to enjoy fulfilling lives and good mental health.”

Professor Simon Baron-Cohen, Director of the Autism Research Centre and a member of the team, said: “This new study is an important example of applied health research with policy relevance for health and social care services.”