Male‐to‐female gender dysphoria: Gender‐specific differences in resting‐state networks

Abstract

IntroductionRecent research found gender‐related differences in resting‐state functional connectivity (rs‐FC) measured by functional magnetic resonance imaging (fMRI). To the best of our knowledge, there are no studies examining the differences in rs‐FC between men, women, and individuals who report a discrepancy between their anatomical sex and their gender identity, i.e. gender dysphoria (GD).MethodsTo address this important issue, we present the first fMRI study systematically investigating the differences in typical resting‐state networks (RSNs) and hormonal treatment effects in 26 male‐to‐female GD individuals (MtFs) compared with 19 men and 20 women.ResultsDifferences between male and female control groups were found only in the auditory RSN, whereas differences between both control groups and MtFs were found in the auditory and fronto‐parietal RSNs, including both primary sensory areas (e.g. calcarine gyrus) and higher order cognitive areas such as the middle and posterior cingulate and dorsomedial prefrontal cortex. Overall, differences in MtFs compared with men and women were more pronounced before cross‐sex hormonal treatment. Interestingly, rs‐FC between MtFs and women did not differ significantly after treatment. When comparing hormonally untreated and treated MtFs, we found differences in connectivity of the calcarine gyrus and thalamus in the context of the auditory network, as well as the inferior frontal gyrus in context of the fronto‐parietal network.ConclusionOur results provide first evidence that MtFs exhibit patterns of rs‐FC which are different from both their assigned and their aspired gender, indicating an intermediate position between the two sexes. We suggest that the present study constitutes a starting point for future research designed to clarify whether the brains of individuals with GD are more similar to their assigned or their aspired gender.

Possible Neurobiological Underpinnings of Homosexuality and Gender Dysphoria

“…With regard to the third metric used in the present study, the rs-fMRI, the data are sparse. Ute Habel's group, however, investigated several different networks in a TrW population of mixed sexual orientation, and found that "untreated" TrW had a "weaker" functional connectivity not only in the inferior temporal lobe in relation to male (presumably heterosexual) controls but also in the right calcarine gyrus and the left dorsolateral prefrontal cortex in relation to TrW who had received cross-sex hormonal treatment (Clemens et al 2017). These data concur with the present findings of weaker functional connectivity among TrW and TrM.…”

Neural Correlates of Gender Face Perception in Transgender People

“…In addition. differences in resting-state brain networks in transgender women compared to cisgender ones have been reported [ 21 , 22 ]. Moreover, combining both resting-state functional connectivity and behavioral data, gender identity in transgender and in cisgender persons has been recently examined, showing that machine learning algorithms could predict distinct brain connectivity patterns in cis and trans people [ 23 ].…”

Sex Differences in QEEG in Psychopath Offenders

“…The pattern of sex differences in the synchronization in our study was consistent with previous findings of sex differences in other psychiatric diagnosis. [73][74][75][76] The synchronization differences found between both sexes could indicate that male offenders have some type of functional impairment associated with cortical connections involved in decision making and emotional regulation different from females.…”

“…The pattern of sex differences in the synchronization in our study was consistent with previous findings of sex differences in other psychiatric diagnosis. 73-76…”