CAMBRIDGE, U.K.—According to a new study by scientists at the University of Cambridge’s Autism Research Centre, transgender and gender-diverse adults are three to six times more likely as cisgender adults to be diagnosed as autistic.
The article, entitled “Elevated rates of autism, other neurodevelopmental and psychiatric diagnoses and autistic traits in transgender and gender-diverse individuals,” has been published today in Nature Communications. This research, conducted using data from over 600,000 adult individuals, confirms previous smaller scale studies.
The team used five different datasets, including a dataset of over 500,000 individuals collected as a part of a Channel 4 documentary entitled “Are you autistic?” In these datasets, participants provided information about their gender identity, and if they had received a diagnosis of autism or other psychiatric conditions like 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. The study looked into the co-occurrence between gender identity and autism, but researchers did not investigate causation.
“These associations between gender identity and autism diagnoses are unlikely to be false positives for multiple reasons … we observe consistent effect directions across multiple datasets with very different recruitment strategies, ascertainment biases, cultural backgrounds, and age ranges,” says the article. “The effects after accounting for age and educational attainment were statistically significant for four of the five datasets, and in the same direction for the fifth.”
The study used data from adults who indicated that they had received an autism diagnosis, but it’s likely that many people on the autistic spectrum could be undiagnosed. An estimated 1.1 percent of the UK population is thought to be autistic, and this result suggests that around 3.5-6.5 percent of transgender and gender-diverse adults are on the autistic spectrum.
“We are beginning to learn more about how the presentation of autism differs in cisgender men and women,” explained Dr. Meng-Chuan Lai, a collaborator on the study at the University of Toronto. “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 personalized 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. On average, transgender and gender-diverse people scored higher on measures of autistic traits compared to cisgender people, regardless of whether they had been diagnosed with autism.
“[T]his association with gender identity is not specific to autism,” the study states. “In two datasets, transgender and gender-diverse individuals also had elevated rates of ADHD, bipolar disorder, depression, OCD, learning disorders, and schizophrenia compared to cisgender individuals. In one of the two datasets, we tested and confirmed that transgender and gender-diverse individuals had higher rates of learning disorders compared to cisgender individuals. In the C4 dataset, we identified elevated rates of schizophrenia in transgender and gender-diverse individuals compared to cisgender individuals, but were unable to replicate this in the MU dataset.”
“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,” added Dr. Varun Warrier, who led the study.
“Whilst our study does not test causality, a few hypotheses may explain the over-representation of autism and other neurodevelopmental and psychiatric conditions in transgender and gender-diverse individuals. First, autistic individuals may conform less to societal norms compared to non-autistic individuals, which may partly explain why a greater number of autistic individuals identify outside the stereotypical gender binary,” the study explains. “Second, prenatal mechanisms (e.g., sex steroid hormones) shaping brain development have been shown to contribute to both autism (and associated neurodevelopmental conditions) and gender role behavior. It is unclear if prenatal sex steroid hormones also contribute to gender identity and this should be investigated in future studies.”
A better understanding of gender diversity in autistic individuals will help provide better access to health care and post-diagnostic support for autistic people who are transgender and gender-diverse.
“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,” stated Professor Simon Baron-Cohen, director of the Autism Research Centre at Cambridge and a member of the research team.
