Transgender adults are up to six times more likely to be diagnosed as autistic, researchers claim.
UK scientists analysed data from 600,000 adults, drawn from five different datasets, including individuals questioned as part of a Channel 4 documentary.
They found that rates of autism among transgender adults far surpassed the numbers for the British population as a whole.
While just over 1 per cent of the UK population is estimated to be on the autistic spectrum, up to 6.5 per cent of gender-diverse adults are on the autistic spectrum.
Transgender and gender-diverse individuals were also more likely to indicate that they had received diagnoses of mental health conditions, particularly depression.
A better understanding of gender diversity in autistic individuals will help provide better access to health care and post-diagnostic support, the experts say.
‘This finding, using large datasets, confirms that the co-occurrence between being autistic and being transgender and gender-diverse is robust,’ said study lead author Dr Varun Warrier at the University of Cambridge.
‘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.’
Gender diverse individuals are defined as those who identify as belonging to a gender or genders outside of male or female.
As an example, ‘agender’ describes someone who does not identify as having a gender identity, while ‘two spirit’ refers to someone who identifies as having both a masculine and a feminine spirit.
Whilst several studies have investigated rates of autism in individuals who are birth-assigned as males and females, there is still limited information on rates of autism in transgender and gender-diverse individuals in the general population, the Cambridge team say.
The researchers used five different datasets, including a dataset of over 500,000 individuals collected as a part of the Channel 4 documentary ‘Are you autistic?’, aired in 2018.
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, which include difficulty with social interaction and resistance to changing routines.
Across all five datasets, transgender and gender-diverse adult individuals were between three and six times more likely to indicate that they were diagnosed as autistic.
This was compared to people whose gender identity corresponds to their sex at birth, commonly known as ‘cisgender’.
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 per cent of the UK population is estimated to be on the autistic spectrum, this result would suggest that somewhere between 3.5 per cent and 6.5 per cent of transgender and gender-diverse adults are on the autistic spectrum.
‘Understanding how autism manifests in transgender and gender-diverse people will enrich our knowledge about autism in relation to gender and sex,’ said Dr Meng-Chuan Lai, a collaborator on the study at the University of Toronto.
‘This enables clinicians to better recognise autism and provide personalised support and health care.’
Transgender and gender diverse people were also more than twice as likely as to have experienced depression.
On average, they also scored higher on measures of autistic traits, regardless of whether they had an autism diagnosis.
The study did not investigate whether gender identity and autism or the other way round, however.
‘Both autistic individuals and transgender and gender-diverse individuals are marginalized and experience multiple vulnerabilities,’ said Professor Simon Baron-Cohen, director of the Autism Research Centre at Cambridge.
‘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.’
The study has been published in Nature Communications.