A small European study adds to the growing body of evidence that brain structure and activity patterns in adolescent transgender individuals more closely resembles that typical of their desired gender than the gender assigned at birth.
"Although more research is needed, we now have evidence that sexual differentiation of the brain differs in young people with GD," lead author Dr Julie Bakker commented about her team’s findings, set to be presented today at the European Society of Endocrinology annual meeting in Barcelona.
"We will then be better equipped to support these young people, instead of just sending them to a psychiatrist and hoping that their distress will disappear spontaneously."
Following decades of research into genetic and epigenetic factors, medical providers and mental health experts in most western nations have, thankfully, embraced the leading theory that sexual orientation and gender identity are hardwired into the brain during fetal development.
These breakthroughs are particularly relevant for individuals with transgenderism – an identification with the opposite gender than the one assigned at birth. Before the wider scientific community accepted the fact that gender identity is innate, the anxiety and distress experienced by transgender people from a very young age because they don’t feel at home in their body – gender dysphoria (GD) – used to be considered a psychiatric disorder.
Now, GD is officially recognized as a condition that requires care to prevent serious psychological repercussions later in life. Given the emotional challenges of growing up transgender, plus the need for hormone therapy to either delay puberty or develop one’s desired gender’s physical characteristics, experts agree that early diagnosis of transgenderism is crucial to giving such individuals the best start in life.
Hoping to find an efficient diagnostic tool to that end, Bakker and her colleagues turned to real-time MRI, which allows researchers to measure the size of brain regions and watch how they activate in response to stimuli.
Their investigation included eight groups with 20 subjects of each: cisgender male and cisgender female prepuberty children, GD male and GD female children, cisgender male and cisgender female adolescents, and GD male and GD female adolescents. The subjects were put in the MRI while fit with a nasal tube administering air mixed with a male pheromone called androstadienone, which is known to elicit greater hypothalamus activation in cisgender females than cisgender males. During a separate control session, they were scanned while receiving pure air.
“We found that hypothalamic responses of both adolescent girls and boys diagnosed with GD were more similar to their experienced gender than their birth sex, which supports the hypothesis of a sex-atypical brain differentiation in these individuals,” the authors wrote.
A subsequent analysis of different brain areas confirmed that gray matter volumes of GD girls and boys of both age groups resemble that of their desired sex. Interestingly, the team also found that adolescent GD girls have atypical resting state neural connectivity in their visual processing network, suggesting that people with GD have altered signaling in the pathways that mediate perception of the self and body.