Autism and gender dysphoria are caused by hormones babies are exposed to in the womb, experts claim

The disorder of gender dysphoria has puzzled scientists for decades: why is it that some people feel they are born in the wrong body, while others don't?

Now, experts speaking to DailyMail.com believe one common characteristic among this group, estimated to be in the region of 1.4million Americans, may offer some explanation.

Research has shown those who do not identify with the sex they were assigned at birth are up to six times more likely to be autistic than people without gender dysphoria.

The developmental disorder, which affects how people communicate, socialize and behave, is thought to overlap with gender dysphoria for a variety of reasons.

Several studies have suggested exposure to certain hormones in the womb could increase the likelihood of both problems, while some experts say the link could lie in a shared refrain from conforming to societal norms.

One of the largest studies ever to examine a potential link between ASD and GD involved data from more than 641,000 people. 

The study, published in Nature Communications in 2020, found people who do not identify with the sex they were assigned at birth are three to six times more likely to be autistic than people without gender divergence. 

Dr Amethysta Herrick, a chemist and trans-education activist, who is a transwoman, told DailyMail.com believes this could be because people on the autism spectrum 'have the freedom to explore their identities and express themselves the way they would choose because social norms matter less.' 

The 2020 study showed transgender and gender-diverse people scored higher on self-reporting measures of autistic traits, including sensory sensitivity, which is often a characteristic of autism.

Following the study and based on his own observations, Dr Michael Craig, a professor of psychiatry, psychology and neuroscience at Kings College London in the UK, concluded there is an inherent link between gender dysphoria and autism. 

Dr Craig, who was also the lead for the NHS National Autism Unit, told The Times: 'There were certainly some days where I was fairly convinced 40 to 50 percent of the patients I was seeing were autistic.

'I was trying to find out what it is that might explain this overlap, but it’s a difficult area to research for all sorts of reasons.'

Overall, he estimated about 20 percent of patients he observed at the Tavistock gender clinic in London might have qualified for an autism diagnosis. 

While no definitive connection has been discovered, the authors of the 2020 study proposed several possible links between autism and gender-diversity.

They wrote that autistic individuals may conform less to societal norms compared to people not diagnosed with the condition, 'which may partly explain why a greater number of autistic individuals identify outside the stereotypical gender binary.'

Second, prenatal hormones involved in shaping brain development have been shown to contribute to both autism and gender role behaviors. 

Previous studies have examined the link between prenatal hormones and autism. A 2019 study found a link between elevated levels of the female sex hormone estrogen in pregnant women and autism in their children. 

Separate studies in both 2015 and 2018 found pregnant women with high levels of certain sex hormones, including testosterone and progesterone, had an increased risk of having a child with autism. 

Previous research has also examined whether prenatal hormones play a role in gender dysphoria, with one study suggesting high levels of prenatal testosterone in females and low levels in males may contribute to gender dysphoria.

As the study found that gender-diverse individuals have higher rates of neurodevelopmental conditions, Dr Aaron Reuben, a neuropsychologist, told DailyMail.com: 'It is plausible that these conditions could be linked, or that there could be overlap among autism and gender dysphoria. 

'Many neurodevelopmental and psychiatric disorders tend to be comorbid, and we tend to see high rates of other conditions, such as ADHD, in individuals with autism.'

He continued: 'While I think it is highly likely for individuals with autism to have greater risk for developing gender dysphoria - or for rates of gender dysphoria to be higher among individuals with autism when compared to those without autism - I would be skeptical of anyone claiming that autism could “cause” gender dysphoria.

'We know so little about both conditions that I think we are a long way from being able to make causal statements. That said, more investigation of the overlap among the two conditions could lead to new discoveries and a better understanding of both.'

One woman from Florida shared her story of having autism and later coming out as  trans. Laura, 32 from Florida, wrote 'I'm trans, autistic and more common than you'd think' for The Huffington Post in 2019.

She said she was diagnosed on the autism spectrum in her late teens and then later began to transition, writing it took her until late in her life to receive a diagnosis and come out because signs were missed or ignored. 

Laura would make repetitive noises, have trouble sleeping unless her hand was squeezed and struggled to eat common foods. 

She also became distressed over a change in structure or routine. When her symptoms of autism became exacerbated in high school, she received her diagnosis. 

As for her trans status, Laura wrote she 'didn't feel right about living as male' during her childhood, but didn't know how to identify the feeling, and when she hit puberty and began to experience typical male development, she 'realized something was wrong.' 

She wrote: 'As a gay autistic trans woman, I spent a long time assuming I was a statistical anomaly... but it turns out that is simply not the case.' 

Laura wrote that she discovered between eight and 10 percent of children seen at gender clinics meet criteria for autism. 

She added: 'Statistically, this means people who are trans are more likely to be diagnosed on the autism spectrum, and vice versa, and there’s a strong enough correlation to prove that it’s actually surprisingly common for both of these to overlap.' 

However, Laura continued: 'As a trans person on the autism spectrum, this statistical overlap was never explained to me by anyone in the medical field, which led to years of me struggling with unique struggles caused by that overlap.'  

Rates of both autism and gender dysphoria, a clinical diagnosis by a healthcare professional, have been rising over the last two decades in the United States. 

Gender dysphoria diagnoses have soared in every state except one since 2018 - with the average age of diagnosis trending younger. 

An analysis of insurance claims conducted by Komodo Health Inc found between 2017 and 2021, approximately 121,880 children aged six to 17 years old were diagnosed with gender dysphoria.

In 2021, 42,000 were given the diagnosis, a 70 percent increase from 2020.

And children under 18 years old now make up one-fifth of new diagnoses each year.

A report by the health data analytics firm Definitive Healthcare shows the rate of gender dysphoria increased in every state except South Dakota from 2018 to 2022 across all ages.

The sharpest rises over those five years were seen in three Republican-led states: Virginia (274 percent) Indiana (247 percent) and Utah (193 percent).

South Dakota saw a decline of 23 percent between 2018 and 2022.

Greater social acceptance and increased awareness about the condition on the part of doctors can partly explain the increase in cases.

CDC data shows one in 36 children had autism in 2020, compared to one in 68 in 2010 and one in 150 kids in 2000. 

Due to the rising rates, experts are questioning whether the condition is becoming more common or if doctors have become better at recognizing and diagnosing autism.  

There is currently still no standard test for autism, but there have been significant advances in diagnostic capabilities, as well as a greater understanding of the disorder.

Because there is no test for the condition, doctors must rely on a child's developmental history and behavior.

Kids are screened for autism at the 18- and 24-month milestone doctor appointments when a child's language, movement, and thinking skills, as well as behaviors and emotions are evaluated. 

There is no cure but experts say early intervention can make a huge difference, with early detection key in ensuring kids on the spectrum get the help they need.

And now, experts say children being seen at gender clinics should be screened for autism. 

Professor Simon Philip Baron-Cohen at Cambridge University and co-author of the 2020 study, told The Times: 'If at present many young people are being referred for gender dysphoria as an explanation for their depression, and an underlying autism diagnosis is being missed, then it makes good clinical practice to also check for autism too, in case the person’s mental health struggles might also be partly due to not getting support for their autism.

'The two are not mutually exclusive but could be co-occurring conditions, each of which deserves support.' 

He added: '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.'