The transsexual brain – A review of findings on the neural basis of transsexualism

Pain mechanisms in the transgender individual: a review

Specific Aim

Provide an overview of the literature addressing major areas pertinent to pain in transgender persons and to identify areas of primary relevance for future research.

Methods

A team of scholars that have previously published on different areas of related research met periodically though zoom conferencing between April 2021 and February 2023 to discuss relevant literature with the goal of providing an overview on the incidence, phenotype, and mechanisms of pain in transgender patients. Review sections were written after gathering information from systematic literature searches of published or publicly available electronic literature to be compiled for publication as part of a topical series on gender and pain in the Frontiers in Pain Research.

Results

While transgender individuals represent a significant and increasingly visible component of the population, many researchers and clinicians are not well informed about the diversity in gender identity, physiology, hormonal status, and gender-affirming medical procedures utilized by transgender and other gender diverse patients. Transgender and cisgender people present with many of the same medical concerns, but research and treatment of these medical needs must reflect an appreciation of how differences in sex, gender, gender-affirming medical procedures, and minoritized status impact pain.

Conclusions

While significant advances have occurred in our appreciation of pain, the review indicates the need to support more targeted research on treatment and prevention of pain in transgender individuals. This is particularly relevant both for gender-affirming medical interventions and related medical care. Of particular importance is the need for large long-term follow-up studies to ascertain best practices for such procedures. A multi-disciplinary approach with personalized interventions is of particular importance to move forward.

Carving the Biodevelopment of Same-Sex Sexual Orientation at Its Joints

Sexual orientation is a core aspect of human experience and understanding its development is fundamental to psychology as a scientific discipline. Biological perspectives have played an important role in uncovering the processes that contribute to sexual orientation development. Research in this field has relied on a variety of populations, including community, clinical, and cross-cultural samples, and has commonly focused on female gynephilia (i.e., female sexual attraction to adult females) and male androphilia (i.e., male sexual attraction to adult males). Genetic, hormonal, and immunological processes all appear to influence sexual orientation. Consistent with biological perspectives, there are sexual orientation differences in brain development and evidence indicates that similar biological influences apply across cultures. An outstanding question in the field is whether the hypothesized biological influences are all part of the same process or represent different developmental pathways leading to same-sex sexual orientation. Some studies indicate that same-sex sexually oriented people can be divided into subgroups who likely experienced different biological influences. Consideration of gender expression in addition to sexual orientation might help delineate such subgroups. Thus, future research on the possible existence of such subgroups could prove to be valuable for uncovering the biological development of sexual orientation. Recommendations for such future research are discussed.

Exploring gender dysphoria and related outcomes in a prospective cohort study: protocol for the Swedish Gender Dysphoria Study (SKDS)

INTRODUCTION

There has been a drastic increase in the reported number of people seeking help for gender dysphoria in many countries over the last two decades. Yet, our knowledge of gender dysphoria and related outcomes is restricted due to the lack of high-quality studies employing comprehensive approaches. This longitudinal study aims to enhance our knowledge of gender dysphoria; different aspects will be scrutinised, focusing primarily on the psychosocial and mental health outcomes, prognostic markers and, secondarily, on the underlying mechanisms for its origin.

METHODS AND ANALYSIS

The Swedish Gender Dysphoria Study is an ongoing multicentre longitudinal cohort study with 501 registered participants with gender dysphoria who are 15 years old or older. Participants at different phases of their clinical evaluation process can enter the study, and the expected follow-up duration is three years. The study also includes a comparison group of 458 age- and county-matched individuals without gender dysphoria. Data on the core outcomes of the study, which are gender incongruence and experienced gender dysphoria, body satisfaction and satisfaction with gender-affirming treatments, as well as other relevant outcomes, including mental health, social functioning and life satisfaction, are collected via web surveys. Two different research visits, before and after starting on gender-affirming hormonal treatment (if applicable), are planned to collect respective biological and cognitive measures. Data analysis will be performed using appropriate biostatistical methods. A power analysis showed that the current sample size is big enough to analyse continuous and categorical outcomes, and participant recruitment will continue until December 2022.

ETHICS AND DISSEMINATION

The ethical permission for this study was obtained from the Local Ethical Review Board in Uppsala, Sweden. Results of the study will be presented at national and international conferences and published in peer-reviewed journals. Dissemination will also be implemented through the Swedish Gender Dysphoria Study network in Sweden.

Gender Dysphoria Publication Trends: A Bibliometric Analysis between 1900 and 2018

Objective Research on gender dysphoria (GD) has been growing over the last decades with increasing interest in understanding and characterizing the causal relationships between psychological, genetics, hormonal, and sociocultural factors. Changes and acceptance of this condition as non-pathologic have led to significant changes in general perspective and its management over time. Our objective is to carry out a bibliometric analysis to know the publication trends and quality of evidence related to gender dysphoria.

Methods A systematic search and critical review of the literature was carried out between January 1900 and December 2018 to perform a bibliometric analysis. Research was done in the following databases: OVID, PubMed, EMBASE, Scopus, Web of Science and Google Scholar. The medical subject headings (MeSh) terms used were: gender dysphoria; and surgery and psychology. The results were plotted using the VOSviewer version 1.6.8. Statistical analyses were performed with the IBM SPSS, Version 25.0.

Results A total of 1,239 manuscripts were identified, out of which 1,041 were selected. The average number of cited times per year per manuscript is 1.84 (interquartile range [IQR] 0-2.33). The average impact index was 47.8 (IQR 20-111.6). The median of total citations per manuscript was 3 (IQR 0-33.1), and the highest number of citations per manuscript was 484. Most publications focus on the psychological aspects of GD, and there is a significant amount of manuscripts related to social and anthropological issues. Most articles have a low level of scientific evidence.

Conclusion There is a great amount of published literature on GD; however, there is a significant level of disagreement in many respects on this topic. Regarding surgical gender-affirmation, there is a lack of information supported by high level of evidence to uphold the emerging expansion of medical practices.

Should chromosomal analysis be performed routinely during the baseline evaluation of the gender affirmation process? The outcomes of a large cohort of gender dysphoric individuals

The role of genetics in the etiology of gender dysphoria (GD) is an important yet understudied area. Yet whether genetic analysis should be carried out during the gender affirmation process at all is a matter of debate. This study aims to evaluate the cytogenetic and molecular genetic findings of individuals with GD. We retrospectively reviewed the medical records of individuals with GD who were followed up in a tertiary clinic. After the exclusion criteria were applied, the study sample consisted of 918 individuals with GD; 691 of whom had female-to-male (FtM) and 227 male-to-female (MtF) GD. The cytogenetic analysis revealed that 223 out of 227 (98.2%) individuals with MtF GD had the 46,XY karyotype, while 683 out of 691 (98.8%) individuals with FtM GD had the 46,XX karyotype. In the Y chromosome microdeletion analysis, azospermic factor c (AZFc) deletion was detected in only two individuals with MtF GD. Our findings suggest that there are few chromosomal abnormalities in individuals with GD. Thus, this research calls into question both the role of chromosomal abnormalities in GD etiology and why the application of chromosomal analysis is in Turkey a routine part of the baseline evaluation of GD.

Brain Sex in Transgender Women Is Shifted towards Gender Identity

Transgender people report discomfort with their birth sex and a strong identification with the opposite sex. The current study was designed to shed further light on the question of whether the brains of transgender people resemble their birth sex or their gender identity. For this purpose, we analyzed a sample of 24 cisgender men, 24 cisgender women, and 24 transgender women before gender-affirming hormone therapy. We employed a recently developed multivariate classifier that yields a continuous probabilistic (rather than a binary) estimate for brains to be male or female. The brains of transgender women ranged between cisgender men and cisgender women (albeit still closer to cisgender men), and the differences to both cisgender men and to cisgender women were significant (p = 0.016 and p < 0.001, respectively). These findings add support to the notion that the underlying brain anatomy in transgender people is shifted away from their biological sex towards their gender identity.

Neuroradiology in Transgender Care: Facial Feminization, Laryngeal Surgery, and Beyond

Transgender individuals experience incongruence between their gender identity and the sex assigned to them at birth. This incongruence can cause many transgender individuals to experience distressing physical and mental discord, a diagnosis known as gender dysphoria. Craniofacial structures have distinct anthropometric characteristics that affect perceived masculinity and femininity. The face, neck, and voice are highly exposed anatomic areas that have recognizable gender-specific characteristics that may hinder a transgender individual's successful social integration and public acceptance. Reconstructive facial and laryngeal procedures are among the surgical options transgender persons may elect to undergo to better align their physical appearance with their gender identity. These include feminization surgeries such as facial feminization and reduction chondrolaryngoplasty, as well as masculinizing facial and laryngeal surgeries. Maxillofacial CT is frequently used in the preoperative evaluation of patients before facial feminization surgery (FFS). Several CT measurements guide surgeons to the optimal correction required in FFS to achieve appropriate aesthetic planes. Mapping important craniofacial landmarks to avoid untoward surgical complications is crucial. Transgender patients may encounter other neurologic complications that require neuroimaging evaluation. For example, gender-affirming hormone therapy (eg, estrogen and testosterone) may increase the risk of stroke or may influence growth of various hormone-sensitive tumors such as pituitary adenomas. Radiologists may interpret imaging examinations in transgender patients for routine care or for evaluation before and after facial and laryngeal surgeries and must be aware of the role of neuroimaging in the care of this population. An invited commentary by Callen is available online. The online slide presentation from the RSNA Annual Meeting is available for this article. ^©RSNA, 2022.

Oral health status among transgender young adults: a cross-sectional study

BACKGROUND

Transgender and gender nonconforming (TGNC) people are a marginalized set of the population that continues to experience health care inequalities. This study aimed to assess oral health parameters including Candida growth and intensity among TGNC adults.

METHODS

This cross-sectional study recruited two subgroups: 40 transgender and 40 control adults. Consented participants were interviewed and clinically examined. Data using the WHO oral health assessment forms were obtained. Samples for Candida growth and intensity analysis were collected from the dorsum surface of the tongue.

RESULTS

27.5% of the transgender group was HIV seropositive. Oral nicotine stomatitis and leukoplakia are reported to be the most prevalent intra-oral lesions showing a prevalence of 27.5% and 20%, respectively. The dental and periodontal health parameters of the transgender group were worse than those of the control group. The intensity of Candida colonies was significantly higher in the test group (p = 0.014).

CONCLUSION

Poor oral health and significant oral mucosal disorders were reported in transgender adults that have shown a higher rate of behavioral risk factors such as tobacco and alcohol consumption. Further longitudinal studies in different world regions are warranted to understand the barriers to good oral health in transgender adults and how to implement effective prevention and management strategies.

Structural, Functional, and Metabolic Brain Differences as a Function of Gender Identity or Sexual Orientation: A Systematic Review of the Human Neuroimaging Literature

This review systematically explored structural, functional, and metabolic features of the cisgender brain compared with the transgender brain before hormonal treatment and the heterosexual brain compared to the homosexual brain from the analysis of the neuroimaging literature up to 2018, and identified and discussed subsequent studies published up to March 2021. Our main aim was to help identifying neuroradiological brain features that have been related to human sexuality to contribute to the understanding of the biological elements involved in gender identity and sexual orientation. We analyzed 39 studies on gender identity and 24 on sexual orientation. Our results suggest that some neuroanatomical, neurophysiological, and neurometabolic features in transgender individuals resemble those of their experienced gender despite the majority resembling those from their natal sex. In homosexual individuals the majority resemble those of their same-sex heterosexual population rather than their opposite-sex heterosexual population. However, it is always difficult to interpret findings with noninvasive neuroimaging. Given the gross nature of these measures, it is possible that more differences too subtle to measure with available tools yet contributing to gender identity and sexual orientation could be found. Conflicting results contributed to the difficulty of identifying specific brain features which consistently differ between cisgender and transgender or between heterosexual and homosexual groups. The small number of studies, the small-to-moderate sample size of each study, and the heterogeneity of the investigations made it impossible to meta-analyze all the data extracted. Further studies are necessary to increase the understanding of the neurological substrates of human sexuality.

Transgender debates and healthcare: A critical realist account

The meta-theoretical resource of critical realism (CR) is deployed in order to examine transgender and healthcare. CR treads a middle way between positivism and postmodernism, within post-Popperian discussions of the philosophy of natural and social science. It focuses on the conditions of possibility for the emergence of a phenomenon under investigation. In this case, the focus is on the emergence of debates about transgenderism in healthcare. These have been technological (about the prospect of biomedical solutions to personal problems) and ideological, with the enlarged salience of identity politics and our currently unresolved "culture wars." Identity politics have brought a focus on epistemological privilege or "lived experience" and on rights to healthcare being driven by consumer choice. The current contestation and its history are discussed in relation to our four planar social being (nature, relationality, socio-economic structures, and our particular personalities) and future scenarios are rehearsed.

Characterization of the 1H-MRS Metabolite Spectra in Transgender Men with Gender Dysphoria and Cisgender People

Much research has been conducted on sexual differences of the human brain to determine whether and to what extent a brain gender exists. Consequently, a variety of studies using different neuroimaging techniques attempted to identify the existence of a brain phenotype in people with gender dysphoria (GD). However, to date, brain sexual differences at the metabolite level using magnetic resonance spectroscopy (1H-MRS) have not been explored in transgender people. In this study, 28 cisgender men (CM) and 34 cisgender women (CW) and 29 transgender men with GD (TMGD) underwent 1H-MRS at 3 Tesla MRI to characterize common brain metabolites. Specifically, levels of N-acetyl aspartate (NAA), choline (Cho), creatine (Cr), glutamate and glutamine (Glx), and myo-inositol + glycine (mI + Gly) were assessed in two brain regions, the amygdala-anterior hippocampus and the lateral parietal cortex. The results indicated a sex-assigned at birth pattern for Cho/Cr in the amygdala of TMGD. In the parietal cortex, a sex-assigned at birth and an intermediate pattern were found. Though assessed post-hoc, exploration of the age of onset of GD in TMGD demonstrated within-group differences in absolute NAA and relative Cho/Cr levels, suggestive for a possible developmental trend. While brain metabolite levels in TMGD resembled those of CW, some interesting findings, such as modulation of metabolite concentrations by age of onset of GD, warrant future inquiry.

Sex Matters: A Multivariate Pattern Analysis of Sex- and Gender-Related Neuroanatomical Differences in Cis- and Transgender Individuals Using Structural Magnetic Resonance Imaging

Univariate analyses of structural neuroimaging data have produced heterogeneous results regarding anatomical sex- and gender-related differences. The current study aimed at delineating and cross-validating brain volumetric surrogates of sex and gender by comparing the structural magnetic resonance imaging data of cis- and transgender subjects using multivariate pattern analysis. Gray matter (GM) tissue maps of 29 transgender men, 23 transgender women, 35 cisgender women, and 34 cisgender men were created using voxel-based morphometry and analyzed using support vector classification. Generalizability of the models was estimated using repeated nested cross-validation. For external validation, significant models were applied to hormone-treated transgender subjects (n = 32) and individuals diagnosed with depression (n = 27). Sex was identified with a balanced accuracy (BAC) of 82.6% (false discovery rate [pFDR] < 0.001) in cisgender, but only with 67.5% (pFDR = 0.04) in transgender participants indicating differences in the neuroanatomical patterns associated with sex in transgender despite the major effect of sex on GM volume irrespective of the self-identification as a woman or man. Gender identity and gender incongruence could not be reliably identified (all pFDR > 0.05). The neuroanatomical signature of sex in cisgender did not interact with depressive features (BAC = 74.7%) but was affected by hormone therapy when applied in transgender women (P < 0.001).

Gender Identity Disorders: Current Medical and Social Paradigm and the ICD-11 Innovations

Introduction. This article presents a review of current concepts of gender identity under normal and pathological conditions. Aim. To analyse the impact of the medical and social paradigm shift for clinical practice. Results and discussion. The modern academic literature devoted to gender identity disorders is characterized by a variety of terminology, a shift in emphasis from clinical judgement to a socially beneficial normocentric approach and a relatively few advanced, evidence-based research. There is also a lack of evidence for the gender theory underlying the new approach, which raises serious doubts about the validity of the medical and social paradigm revision. In the same time, the position of Russian psychiatrists remains to be more clinically oriented. Conclusion. Patients who declare the desire to reassign their gender have to be assessed by psychiatrists for differential diagnosis to exclude a mental disorder. In such cases, the destigmatization of mental disorders is more critical than the depathologization of gender identity disorders.

The Neuroanatomy of Transgender Identity: Mega-Analytic Findings From the ENIGMA Transgender Persons Working Group

BACKGROUND

In contrast to cisgender persons, transgender persons identify with a different gender than the one assigned at birth. Although research on the underlying neurobiology of transgender persons has been accumulating over the years, neuroimaging studies in this relatively rare population are often based on very small samples resulting in discrepant findings.

AIM

To examine the neurobiology of transgender persons in a large sample.

METHODS

Using a mega-analytic approach, structural MRI data of 803 non-hormonally treated transgender men (TM, n = 214, female assigned at birth with male gender identity), transgender women (TW, n = 172, male assigned at birth with female gender identity), cisgender men (CM, n = 221, male assigned at birth with male gender identity) and cisgender women (CW, n = 196, female assigned at birth with female gender identity) were analyzed.

OUTCOMES

Structural brain measures, including grey matter volume, cortical surface area, and cortical thickness.

RESULTS

Transgender persons differed significantly from cisgender persons with respect to (sub)cortical brain volumes and surface area, but not cortical thickness. Contrasting the 4 groups (TM, TW, CM, and CW), we observed a variety of patterns that not only depended on the direction of gender identity (towards male or towards female) but also on the brain measure as well as the brain region examined.

CLINICAL TRANSLATION

The outcomes of this large-scale study may provide a normative framework that may become useful in clinical studies.

STRENGTHS AND LIMITATIONS

While this is the largest study of MRI data in transgender persons to date, the analyses conducted were governed (and restricted) by the type of data collected across all participating sites.

CONCLUSION

Rather than being merely shifted towards either end of the male-female spectrum, transgender persons seem to present with their own unique brain phenotype. Mueller SC, Guillamon A, Zubiaurre-Elorza L, et al. The Neuroanatomy of Transgender Identity: Mega-Analytic Findings From the ENIGMA Transgender Persons Working Group. J Sex Med 2021;18:1122-1129.

2D:4D Digit Ratios in Adults with Gender Dysphoria: A Comparison to Their Unaffected Same-Sex Heterosexual Siblings, Cisgender Heterosexual Men, and Cisgender Heterosexual Women

We compared gender dysphoria (GD) patients and their same-sex siblings in terms of their 2D:4D ratios, which may reflect prenatal exposure to androgen, one of the possible etiological mechanisms underlying GD. Sixty-eight GD patients (46 Female-to-Male [FtM]; 22 Male-to-Female [MtF]), 68 siblings (46 sisters of FtMs; 22 brothers of MtFs), and 118 heterosexual controls (62 female; 56 male) were included in the study. FtMs were gynephilic and MtFs were androphilic. We found that 2D:4D ratios in the both right hand (p < .001) and the left hand (p = .003) were lower in male controls than in female controls. Regarding right hands, FtM GD patients had lower 2D:4D ratios than female controls (p < .001) but their ratios did not differ from those of their sisters or male controls. FtM GD patients had no significant difference in their left-hand 2D:4D ratios compared to their sisters or female and male controls. While there was no significant difference in right hands between FtM's sisters and male controls, left-hand 2D:4D ratios were significantly higher in FtM's sisters (p = .017). MtF GD patients had lower right-hand 2D:4D ratios than female controls (p <.001), but their right-hand ratios did not differ from those of their brothers and male controls. There was no significant difference in left-hand 2D:4D ratios between MtF GD patients, and their brothers, or female and male controls. FtM GD patients showed significantly masculinized right-hand 2D:4D ratios, while there was no evidence of feminization in MtF GD patients.

Dump the "dimorphism": Comprehensive synthesis of human brain studies reveals few male-female differences beyond size

With the explosion of neuroimaging, differences between male and female brains have been exhaustively analyzed. Here we synthesize three decades of human MRI and postmortem data, emphasizing meta-analyses and other large studies, which collectively reveal few reliable sex/gender differences and a history of unreplicated claims. Males' brains are larger than females' from birth, stabilizing around 11 % in adults. This size difference accounts for other reproducible findings: higher white/gray matter ratio, intra- versus interhemispheric connectivity, and regional cortical and subcortical volumes in males. But when structural and lateralization differences are present independent of size, sex/gender explains only about 1% of total variance. Connectome differences and multivariate sex/gender prediction are largely based on brain size, and perform poorly across diverse populations. Task-based fMRI has especially failed to find reproducible activation differences between men and women in verbal, spatial or emotion processing due to high rates of false discovery. Overall, male/female brain differences appear trivial and population-specific. The human brain is not "sexually dimorphic."

A Universally Accepted Definition of Gender Will Positively Impact Societal Understanding, Acceptance, and Appropriateness of Health Care

When individuals do not conform to stereotypes associated with "male" or "female," they are often ridiculed, bullied, and rejected, which leads to depression, psychological problems, and even suicide. The number of individuals who identify themselves as transgender, gender queer, or who do not conform to societal norms with respect to gender appears to be increasing. Despite this apparent increase, clinicians and health care facilities are ill-prepared to meet the needs of these individuals in a professional and appropriate manner. Unfortunately, there is an inherit distrust of the medical community by individuals who do not conform to societal norms with respect to gender because of a perception that the medical community does not understand the unique challenges of these individuals. Therefore, reducing the social stigma associated with gender nonconforming individuals is one way to begin to break down barriers of distrust and enhance communication within and outside the medical community. In this review, we discuss the scant amount of scientific data on the biological origins of gender identity. We highlight the fact that the biological definition of gender remains elusive in part because molecular and biological techniques have not been available to accurately probe the development of gender identity. We therefore advocate for the importance of enhancing our knowledge of the origins of gender identity with advanced scientific tools. Enhancing scientific understanding of the biological origins of gender identity may reduce stigma and barriers to care.

Neuroanatomy of transgender persons in a Non-Western population and improving reliability in clinical neuroimaging

Although the neuroanatomy of transgender persons is slowly being charted, findings are presently discrepant. Moreover, the major body of work has focused on Western populations. One important factor is the issue of power and low signal-to-noise (SNR) ratio in neuroimaging studies of rare study populations including endocrine or neurological patient groups. The present study focused on the structural neuroanatomy of a Non-Western (Iranian) sample of 40 transgender men (TM), 40 transgender women (TW), 30 cisgender men (CM), and 30 cisgender women (CW), while assessing whether the reliability of findings across structural anatomical measures including gray matter volume (GMV), cortical surface area (CSA), and cortical thickness (CTh) could be increased by using two back-to-back within-session structural MRI scans. Overall, findings in transgender persons were more consistent with sex assigned at birth in GMV and CSA, while no group differences emerged for CTh. Repeated measures analysis also indicated that having a second scan increased SNR in all regions of interest, most notably bilateral frontal poles, pre- and postcentral gyri and putamina. The results suggest that a simple time and cost-effective measure to improve SNR in rare clinical populations with low prevalence rates is a second anatomical scan when structural MRI is of interest.

Gender Dysphoria in Adults: An Overview and Primer for Psychiatrists

(Copyright © William Byne et al. 2018; Published by Mary Ann Liebert, Inc. This Open Access article is distributed under the terms of the Creative Commons License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.).

Gender-affirming hormone treatment - A unique approach to study the effects of sex hormones on brain structure and function

Investigating the effects of the gender-affirming hormone treatment of transgender people using neuroimaging provides a unique opportunity to study the impact of high dosages of sex hormones on human brain structure and function. This line of research is of relevance from a basic neuroscientific as well as from a psychiatric viewpoint. Prevalence rates, etiopathology, and disease course of many psychiatric disorders exhibit sex differences which are linked to differences in sex hormone levels. Here, we review recent neuroimaging studies from others and our group that investigate the effects of gender-affirming hormone treatment in a longitudinal design utilizing structural and functional magnetic resonance imaging and positron emission tomography. Studies point to a general anabolic and anticatabolic effect of testosterone on grey and white matter structure, whereas estradiol and antiandrogen treatment seems to have partly opposite effects. Moreover, preliminary research indicates that gender-affirming hormone treatment influences serotonergic neurotransmission, a finding that is especially interesting for psychiatry. A clear picture of a hormonal influence on brain activity has yet to emerge. In conclusion, the available evidence reviewed here clearly indicates that sex hormone applications influence brain structure and function in the adult human brain.

The Role of Sex and Sex Hormones in Neurodegenerative Diseases

Neurodegenerative diseases (NDs) are a wide class of disorders of the central nervous system (CNS) with unknown etiology. Several factors were hypothesized to be involved in the pathogenesis of these diseases, including genetic and environmental factors. Many of these diseases show a sex prevalence and sex steroids were shown to have a role in the progression of specific forms of neurodegeneration. Estrogens were reported to be neuroprotective through their action on cognate nuclear and membrane receptors, while adverse effects of male hormones have been described on neuronal cells, although some data also suggest neuroprotective activities. The response of the CNS to sex steroids is a complex and integrated process that depends on (i) the type and amount of the cognate steroid receptor and (ii) the target cell type-either neurons, glia, or microglia. Moreover, the levels of sex steroids in the CNS fluctuate due to gonadal activities and to local metabolism and synthesis. Importantly, biochemical processes involved in the pathogenesis of NDs are increasingly being recognized as different between the two sexes and as influenced by sex steroids. The aim of this review is to present current state-of-the-art understanding on the potential role of sex steroids and their receptors on the onset and progression of major neurodegenerative disorders, namely, Alzheimer's disease, Parkinson's diseases, amyotrophic lateral sclerosis, and the peculiar motoneuron disease spinal and bulbar muscular atrophy, in which hormonal therapy is potentially useful as disease modifier.

Predictive Pattern Classification Can Distinguish Gender Identity Subtypes from Behavior and Brain Imaging

The exact neurobiological underpinnings of gender identity (i.e., the subjective perception of oneself belonging to a certain gender) still remain unknown. Combining both resting-state functional connectivity and behavioral data, we examined gender identity in cisgender and transgender persons using a data-driven machine learning strategy. Intrinsic functional connectivity and questionnaire data were obtained from cisgender (men/women) and transgender (trans men/trans women) individuals. Machine learning algorithms reliably detected gender identity with high prediction accuracy in each of the four groups based on connectivity signatures alone. The four normative gender groups were classified with accuracies ranging from 48% to 62% (exceeding chance level at 25%). These connectivity-based classification accuracies exceeded those obtained from a widely established behavioral instrument for gender identity. Using canonical correlation analyses, functional brain measurements and questionnaire data were then integrated to delineate nine canonical vectors (i.e., brain-gender axes), providing a multilevel window into the conventional sex dichotomy. Our dimensional gender perspective captures four distinguishable brain phenotypes for gender identity, advocating a biologically grounded reconceptualization of gender dimorphism. We hope to pave the way towards objective, data-driven diagnostic markers for gender identity and transgender, taking into account neurobiological and behavioral differences in an integrative modeling approach.

The Use of Whole Exome Sequencing in a Cohort of Transgender Individuals to Identify Rare Genetic Variants

Approximately 0.5-1.4% of natal males and 0.2-0.3% of natal females meet DSM-5 criteria for gender dysphoria, with many of these individuals self-describing as transgender men or women. Despite recent improvements both in social acceptance of transgender individuals as well as access to gender affirming therapy, progress in both areas has been hampered by poor understanding of the etiology of gender dysphoria. Prior studies have suggested a genetic contribution to gender dysphoria, but previously proposed candidate genes have not yet been verified in follow-up investigation. In this study, we expand on the topic of gender identity genomics by identifying rare variants in genes associated with sexually dimorphic brain development and exploring how they could contribute to gender dysphoria. To accomplish this, we performed whole exome sequencing on the genomic DNA of 13 transgender males and 17 transgender females. Whole exome sequencing revealed 120,582 genetic variants. After filtering, 441 variants in 421 genes remained for further consideration, including 21 nonsense, 28 frameshift, 13 splice-region, and 225 missense variants. Of these, 21 variants in 19 genes were found to have associations with previously described estrogen receptor activated pathways of sexually dimorphic brain development. These variants were confirmed by Sanger Sequencing. Our findings suggest a new avenue for investigation of genes involved in estrogen signaling pathways related to sexually dimorphic brain development and their relationship to gender dysphoria.

A New Theory of Gender Dysphoria Incorporating the Distress, Social Behavioral, and Body-Ownership Networks

When postmortem studies related to transgender individuals were first published, little was known about the function of the various identified nuclei. Now, over 2 decades later, significant progress has been made associating function with specific brain regions, as well as in identifying networks associated with groups of behaviors. However, much of this progress has not been integrated into the general conceptualization of gender dysphoria in humans.

When postmortem studies related to transgender individuals were first published, little was known about the function of the various identified nuclei. Now, over 2 decades later, significant progress has been made associating function with specific brain regions, as well as in identifying networks associated with groups of behaviors. However, much of this progress has not been integrated into the general conceptualization of gender dysphoria in humans. I hypothesize that in individuals with gender dysphoria, the aspects of chronic distress, gender atypical behavior, and incongruence between perception of gender identity and external primary sex characteristics are all directly related to functional differences in associated brain networks. I evaluated previously published neuroscience data related to these aspects and the associated functional networks, along with other relevant information. I find that the brain networks that give individuals their ownership of body parts, that influence gender typical behavior, and that are involved in chronic distress are different in individuals with and without gender dysphoria, leading to a new theory—that gender dysphoria is a sensory perception condition, an alteration in the sense of gender influenced by the reflexive behavioral responses associated with each of these networks. This theory builds upon previous work that supports the relevance of the body-ownership network and that questions the relevance of cerebral sexual dimorphism in regard to gender dysphoria. However, my theory uses a hierarchical executive function model to incorporate multiple reflexive factors (body ownership, gender typical/atypical behavior, and chronic distress) with the cognitive, reflective process of gender identity.

"Diagnosing" Gender? Categorizing Gender-Identity Variants in the Anthropocene

In recent decades, two interrelated major controversies have been unfolding in the area of sex/gender research. (1) Are gender-identity variants to be understood as psychopathology or natural variation? (2) Is gender (and perhaps even sex) better conceptualized as binary or non-binary? The answer depends on the conceptual context and related considerations of utility. In the context of evolutionary biology, marked variants of sex and gender decrease reproductive success and are, thereby, deemed pathologic. In the present era of the anthropocene, however, the material conditions underlying the traditional division of labor between the sexes and the role of reproductive success have dramatically changed. These changes decrease the psychosocial importance of the binary gender distinction, provide more freedom for non-binary gender expression and identity formation, and render the distinction of pathologic and non-pathologic less useful, unless gender dysphoria develops secondary to a psychiatric condition. Although most people state their gender identity in the form of a nominal category, most self-report or interview-based ratings and multi-item scales of gender expression and/or identity show continuous distributions, either unimodal-asymmetric or bimodal, depending on whether they are designed for one or both of the traditional genders. Similarly, the rating scales of androgen-influenced variants of the genitalia-usually designed for one of the traditional sexes-typically represent a unipolar-asymmetric continuum. However, the binary gender system remains the primary framework against which individuals evaluate themselves. For those who develop gender dysphoria, assistance by mental-health service providers continues to be important.

Untangling the Gordian Knot of Human Sexuality

There is increasing interest in and tolerance of the lay public for variations in human sexuality. In contrast, the molecular biology that underlies gender identity, the development of gonadal and genital anatomy, and the factors that define sexual behavior is proving unexpectedly complex and is still incompletely understood. It is now evident that humans cannot be characterized as member of 1 of 2 clearly defined units: male or female. In fact, individuals exist on a continuum: those who do not conform unequivocally to the dyadic view of human sex in terms of anatomy, gender identity, and/or sexual behavior should be characterized as having variations in rather than disorders of sexual development. Such individuals can no longer be regarded as anomalies to be rejected, condemned, and, if possible, “corrected” either psychologically or anatomically.

Individuals seeking gender reassignment: marked increase in demand for services

Aims and methodTo describe the pattern of referrals and characteristics of people aged over 18 seeking gender reassignment in Oxfordshire over a 6-year period (2011-2016).

RESULTS

A total of 153 individuals attended for assessment (of 162 referred); 97 (63.4%) were natal males and 56 (36.6%) were natal females. Mean age at referral was markedly different between the two groups, with females being younger. The number of referral significantly increased over the time period, by an average of 18% per year (95% CI 1.08-1.30). Eighty-seven patients sought transition from male to female, and 46 from female to male, while a smaller group (n = 13) had non-binary presentations. Twelve patients (7.8%) had autism spectrum disorder.Clinical implicationsThere are various possible reasons for the increased demand for services for people with gender dysphoria, which we discuss here. When planning services in the UK, both the increase in overall referral rates and the apparent earlier age at referral should be taken into account.Declaration of interestNone.

Gender incongruence and the brain - Behavioral and neural correlates of voice gender perception in transgender people

The phenomenon of gender incongruence is hypothesized to arise from a discrepant sexual development of the brain and the genitals, contingent on genetic and hormonal mechanisms. We aimed at visualizing transgender identity on a neurobiological level, assuming a higher functional similarity to individuals of the aspired rather than assigned sex. Implementing a gender perception paradigm featuring male and female voice stimuli, behavioral and functional imaging data of transmen were compared to men and women, and to transwomen, respectively. Men had decreased activation in response to voices of the other sex in regions across the frontoparietal and insular cortex, while the activation patterns of women and transmen were characterized by little or no differentiation between male and female voices. Further, transmen had a comparatively high discrimination performance for ambiguous male voices, possibly reflecting a high sensitivity for voices of the aspired sex. Comparing transmen and transwomen yielded only few differences in the processing of male compared to female voices. In the insula, we observed a pattern similar to that of men and women, the neural responses of the transgender group being in accordance with their gender identity rather than assigned sex. Notwithstanding the similarities found dependent on biological sex, the findings support the hypothesis of gender incongruence being a condition in which neural processing modes are partly incongruent with one's assigned sex.

Neurobiology of gender identity and sexual orientation

Sexual identity and sexual orientation are independent components of a person's sexual identity. These dimensions are most often in harmony with each other and with an individual's genital sex, although not always. The present review discusses the relationship of sexual identity and sexual orientation to prenatal factors that act to shape the development of the brain and the expression of sexual behaviours in animals and humans. One major influence discussed relates to organisational effects that the early hormone environment exerts on both gender identity and sexual orientation. Evidence that gender identity and sexual orientation are masculinised by prenatal exposure to testosterone and feminised in it absence is drawn from basic research in animals, correlations of biometric indices of androgen exposure and studies of clinical conditions associated with disorders in sexual development. There are, however, important exceptions to this theory that have yet to be resolved. Family and twin studies indicate that genes play a role, although no specific candidate genes have been identified. Evidence that relates to the number of older brothers implicates maternal immune responses as a contributing factor for male sexual orientation. It remains speculative how these influences might relate to each other and interact with postnatal socialisation. Nonetheless, despite the many challenges to research in this area, existing empirical evidence makes it clear that there is a significant biological contribution to the development of an individual's sexual identity and sexual orientation.

Gender Dysphoria in Adults: An Overview and Primer for Psychiatrists

Regardless of their area of specialization, adult psychiatrists are likely to encounter gender-variant patients; however, medical school curricula and psychiatric residency training programs devote little attention to their care. This article aims to assist adult psychiatrists who are not gender specialists in the delivery of respectful, clinically competent, and culturally attuned care to gender-variant patients, including those who identify as transgender or transsexual or meet criteria for the diagnosis of Gender Dysphoria (GD) as defined by The Diagnostic and Statistical Manual of Mental Disorders (5th edition). The article will also be helpful for other mental health professionals. The following areas are addressed: evolution of diagnostic nosology, epidemiology, gender development, and mental health assessment, differential diagnosis, treatment, and referral for gender-affirming somatic treatments of adults with GD.

Testosterone Effects on the Brain in Transgender Men

Transgender individuals experience incongruence between their gender identity and birth-assigned sex. The resulting gender dysphoria (GD), which some gender-incongruent individuals experience, is theorized to be a consequence of atypical cerebral sexual differentiation, but support for this assertion is inconsistent. We recently found that GD is associated with disconnected networks involved in self-referential thinking and own body perception. Here, we investigate how these networks in trans men (assigned female at birth with male gender identity) are affected by testosterone. In 22 trans men, we obtained T1-weighted, diffusion-weighted, and resting-state functional magnetic resonance imaging scans before and after testosterone treatment, measuring cortical thickness (Cth), subcortical volumes, fractional anisotropy (FA), and functional connectivity. Nineteen cisgender controls (male and female) were also scanned twice. The medial prefrontal cortex (mPFC) was thicker in trans men than controls pretreatment, and remained unchanged posttreatment. Testosterone treatment resulted in increased Cth in the insular cortex, changes in cortico-cortical thickness covariation between mPFC and occipital cortex, increased FA in the fronto-occipital tract connecting these regions, and increased functional connectivity between mPFC and temporo-parietal junction, compared with controls. Concluding, in trans men testosterone treatment resulted in functional and structural changes in self-referential and own body perception areas.

Conducting neuropsychological assessment with transgender individuals

OBJECTIVE

The purpose of this paper is to provide an overview of helpful clinical practices when working with transgender adult individuals.

METHOD

While the number of openly transgender individuals appears to be growing with society's increased acceptance and awareness, many neuropsychologists have had few opportunities to gain experience with this patient population. In this article, we review the existing literature as it relates to clinical neuropsychological practice.

RESULTS

We describe important terminology, ideals for creating an environment of respect, and how existing clinical guidelines for transgender individuals may apply to neuropsychology. In addition, we review the primary steps in the assessment process and provide a set of principles and recommendations for conducting neuropsychological assessments with transgender patients.

CONCLUSIONS

There is a paucity of guidance in the field for working with transgender individuals. This article represents a step forward in the dialog and we look forward to future research that develops appropriate normative information, increases understanding of psychosocial factors, and better appreciates the range of hormonal influences for transgender individuals.

The art of matching brain tissue from patients and controls for postmortem research

The quality of postmortem research depends strongly on a thorough clinical investigation and documentation of the patient's disorder and therapies. In addition, a systematic and professional neuropathologic investigation of both cases and controls is absolutely crucial. In the experience of the Netherlands Brain Bank (NBB), about 20% of clinical neurologic diagnoses, despite being made in first-rate clinics, have to be revised or require an extra diagnosis after a complete and thorough review by the NBB. The neuropathology examination may reveal for instance that the "controls" already have preclinical neurodegenerative alterations. In postmortem studies the patient and control groups must be matched for as many of the known confounding factors as possible. This is necessary to make the groups as similar as possible, except for the topic being investigated. Confounding factors are present before, during, and after death. They are respectively: (1) genetic background, systemic diseases, duration and gravity of illness, medicines and addictive compounds used, age, sex, gender identity, sexual orientation, circadian and seasonal fluctuations, lateralization; (2) agonal state, stress of dying; and (3) postmortem delay, freezing procedures, fixation and storage time. Consequently, a brain bank should have a large number of controls at its disposal for appropriate matching. If matching fails for some confounders, then their influence may be determined by statistical methods such as analysis of variance or regression models.

Brain functional connectivity patterns in children and adolescents with gender dysphoria: Sex-atypical or not?

Various previous studies have reported that brains of people diagnosed with gender dysphoria (GD) show sex-atypical features. In addition, recent functional magnetic resonance imaging studies found that several brain resting-state networks (RSNs) in adults with GD show functional connectivity (FC) patterns that are not sex-atypical, but specific for GD. In the current study we examined whether FC patterns are also altered in prepubertal children and adolescents with GD in comparison with non-gender dysphoric peers. We investigated FC patterns within RSNs that were previously examined in adults: visual networks (VNs), sensorimotor networks (SMNs), default mode network (DMN) and salience network. Thirty-one children (18 birth assigned males; 13 birth assigned females) and 40 adolescents with GD (19 birth assigned males or transgirls; 21 birth assigned females or transboys), and 39 cisgender children (21 boys; 18 girls) and 41 cisgender adolescents (20 boys; 21 girls) participated. We used independent component analysis to obtain the network maps of interest and compared these across groups. Within one of the three VNs (VN-I), adolescent transgirls showed stronger FC in the right cerebellum compared with all other adolescent groups. Sex differences in FC between the cisgender adolescent groups were observed in the right supplementary motor area within one of the two SMNs (SMN-II; girls>boys) and the right posterior cingulate gyrus within the posterior DMN (boys>girls). Within these networks adolescent transgirls showed FC patterns similar to their experienced gender (female). Also adolescent transboys showed a FC pattern similar to their experienced gender (male), but within the SMN-II only. The prepubertal children did not show any group differences in FC, suggesting that these emerge with aging and during puberty. Our findings provide evidence for the existence of both GD-specific and sex-atypical FC patterns in adolescents with GD.

Cross-sex testosterone therapy in ovariectomized mice: addition of low-dose estrogen preserves bone architecture

Cross-sex hormone therapy (XHT) is widely used by transgender people to alter secondary sex characteristics to match their desired gender presentation. Here, we investigate the long-term effects of XHT on bone health using a murine model. Female mice underwent ovariectomy at either 6 or 10 wk and began weekly testosterone or vehicle injections. Dual-energy X-ray absorptiometry (DXA) was performed (20 wk) to measure bone mineral density (BMD), and microcomputed tomography was performed to compare femoral cortical and trabecular bone architecture. The 6-wk testosterone group had comparable BMD with controls by DXA but reduced bone volume fraction, trabecular number, and cortical area fraction and increased trabecular separation by microcomputed tomography. Ten-week ovariectomy/XHT maintained microarchitecture, suggesting that estrogen is critical for bone acquisition during adolescence and that late, but not early, estrogen loss can be sufficiently replaced by testosterone alone. Given these findings, we then compared effects of testosterone with effects of weekly estrogen or combined testosterone/low-dose estrogen treatment after a 6-wk ovariectomy. Estrogen treatment increased spine BMD and microarchitecture, including bone volume fraction, trabecular number, trabecular thickness, and connectivity density, and decreased trabecular separation. Combined testosterone-estrogen therapy caused similar increases in femur and spine BMD and improved architecture (increased bone volume fraction, trabecular number, trabecular thickness, and connectivity density) to estrogen therapy and were superior compared with mice treated with testosterone only. These results demonstrate estradiol is critical for bone acquisition and suggest a new cross-sex hormone therapy adding estrogens to testosterone treatments with potential future clinical implications for treating transgender youth or men with estrogen deficiency.

Genomic Characteristics of Gender Dysphoria Patients and Identification of Rare Mutations in RYR3 Gene

Gender dysphoria (GD) is characterized by an incongruence between the gender assigned at birth and the gender with which one identifies. The biological mechanisms of GD are unclear. While common genetic variants are associated with GD, positive findings have not always been replicated. To explore the role of rare variants in GD susceptibility within the Han Chinese population, whole-genome sequencing of 9 Han female-to-male transsexuals (FtMs) and whole-exome sequencing of 4 Han male-to-female transsexuals (MtFs) were analyzed using a pathway burden analysis in which variants are first collapsed at the gene level and then by Gene Ontology terms. Novel nonsynonymous variants in ion transport genes were significantly enriched in FtMs (P- value, 2.41E-10; Fold enrichment, 2.8) and MtFs (P- value, 1.04E-04; Fold enrichment, 2.3). Gene burden analysis comparing 13 GD cases and 100 controls implicated RYR3, with three heterozygous damaging mutations in unrelated FtMs and zero in controls (P = 0.001). Importantly, protein structure modeling of the RYR3 mutations indicated that the R1518H mutation made a large structural change in the RYR3 protein. Overall, our results provide information about the genetic basis of GD.

Alcohol-Related Blackouts, Negative Alcohol-Related Consequences, and Motivations for Drinking Reported by Newly Matriculating Transgender College Students

BACKGROUND

Many transgender college students struggle with identity formation and other emotional, social, and developmental challenges associated with emerging adulthood. A potential maladaptive coping strategy employed by such students is heavy drinking. Prior literature has suggested greater consumption and negative alcohol-related consequences (ARCs) in transgender students compared with their cisgender peers, but little is known about their differing experiences with alcohol-related blackouts (ARBs). We examined the level of alcohol consumption, the frequency of ARBs and other ARCs, and motivations for drinking reported by the largest sample of transgender college students to date.

METHODS

A Web survey from an alcohol-prevention program, AlcoholEdu for College™, assessed student demographics and drinking-related behaviors, experiences, and motivations of newly matriculating first-year college students. A self-reported drinking calendar was used to examine each of the following measures over the previous 14 days: number of drinking days, total number of drinks, and maximum number of drinks on any single day. A 7-point Likert scale was used to measure ARCs, ARBs, and drinking motivations. Transgender students of both sexes were compared with their cisgender peers.

RESULTS

A total of 989 of 422,906 students (0.2%) identified as transgender. Over a 14-day period, transgender compared with cisgender students were more likely to consume alcohol over more days, more total drinks, and a greater number of maximum drinks on a single day. Transgender students (36%) were more likely to report an ARB than cisgender students (25%) as well as more negative academic, confrontation-related, social, and sexual ARCs. Transgender respondents more often cited stress reduction, social anxiety, self-esteem issues, and the inherent properties of alcohol as motivations for drinking. For nearly all measures, higher values were yielded by male-to-female than female-to-male transgender students.

CONCLUSIONS

Transgender compared with cisgender first-year students engage in higher-risk drinking patterns and experience more ARBs and other negative ARCs. Broad institutional efforts are required to address the unique circumstances of transgender men and women and to reduce negative ARCs in college students, regardless of their sex or gender identity.

Sex, Gender, and Transgender: Metabolic Impact of Cross Hormone Therapy

Most preclinical and clinical, animal, and human research has been biased with respect to sex and even more so with respect to gender. In fact, little is known about the impact of sex and even less about the influence of gender on overall metabolic processes. The National Institutes of Health has recognized this gap in scientific knowledge and now mandates that studies be conducted in both sexes and to include gender as variables influencing physiological processes such as metabolism. It is therefore critical to understand and appreciate how to incorporate sex and gender in preclinical and clinical research in order to enhance our understanding of the mechanisms by which metabolic processes differ by sex and gender. In this chapter, we define sex and gender and discuss when sex and gender are not aligned, such as that which occurs in transgender individuals, and how this impacts metabolic processes. We discuss the importance of understanding the influence and interactions between sex hormones and sex chromosomes rather than focusing on their relative contributions to metabolism in isolation. This knowledge will optimize therapies specific for individuals which need to encompass sex and gender.

Global Disorders of Sex Development Update since 2006: Perceptions, Approach and Care

The goal of this update regarding the diagnosis and care of persons with disorders of sex development (DSDs) is to address changes in the clinical approach since the 2005 Consensus Conference, since knowledge and viewpoints change. An effort was made to include representatives from a broad perspective including support and advocacy groups. The goal of patient care is focused upon the best possible quality of life (QoL). The field of DSD is continuously developing. An update on the clinical evaluation of infants and older individuals with ambiguous genitalia including perceptions regarding male or female assignment is discussed. Topics include biochemical and genetic assessment, the risk of germ cell tumor development, approaches to psychosocial and psychosexual well-being and an update on support groups. Open and on-going communication with patients and parents must involve full disclosure, with the recognition that, while DSD conditions are life-long, enhancement of the best possible outcome improves QoL. The evolution of diagnosis and care continues, while it is still impossible to predict gender development in an individual case with certainty. Such decisions and decisions regarding surgery during infancy that alters external genital anatomy or removes germ cells continue to carry risk.

Limb amputation and other disability desires as a medical condition

Some people have a profound dissatisfaction with what is considered an able-bodied state by most others. These individuals desire to be disabled, by conventional standards. In this Review, we integrate research findings about the desire for a major limb amputation or paralysis (xenomelia). Neuropsychological and neuroimaging explorations of xenomelia show functional and structural abnormalities in predominantly right hemisphere cortical circuits of higher-order bodily representation, including affective and sexual aspects of corporeal awareness. These neural underpinnings of xenomelia do not necessarily imply a neurological cause, and a full understanding of the condition requires consideration of the interface between neural and social contributions to the bodily self and the concept of disability. Irrespective of cause, disability desires are accompanied by a disabling bodily dysphoria, in many respects similar to gender dysphoria, and we suggest that they should be considered a mental disorder.

Gender identity, gender assignment and reassignment in individuals with disorders of sex development: a major of dilemma

INTRODUCTION

Disorders of Sex Development (DSD) are a wide range of congenital conditions characterized by an incongruence of components involved in sexual differentiation, including gender psychosexual development. The management of such disorders is complex, and one of the most crucial decision is represented by gender assignment. In fact, the primary goal in DSD is to have a gender assignment consistent with the underlying gender identity in order to prevent the distress related to a forthcoming Gender Dysphoria. Historically, gender assignment was based essentially on surgical outcomes, assuming the neutrality of gender identity at birth. This policy has been challenged in the past decade refocusing on the importance of prenatal and postnatal hormonal and genetic influences on psychosexual development.

AIMS

(1) to update the main psychological and medical issues that surround DSD, in particular regarding gender identity and gender assignment; (2) to report specific clinical recommendations according to the different diagnosis.

METHODS

A systematic search of published evidence was performed using Medline (from 1972 to March 2016). Review of the relevant literature and recommendations was based on authors' expertise.

RESULTS

A review of gender identity and assignment in DSD is provided as well as clinical recommendations for the management of individuals with DSD.

CONCLUSIONS

Given the complexity of this management, DSD individuals and their families need to be supported by a specialized multidisciplinary team, which has been universally recognized as the best practice for intersexual conditions. In case of juvenile GD in DSD, the prescription of gonadotropin-releasing hormone analogues, following the World Professional Association for Transgender Health and the Endocrine Society guidelines, should be considered. It should always be taken into account that every DSD person is unique and has to be treated with individualized care. In this perspective, international registries are crucial to improve the understanding of these challenging conditions and clinical practice, in providing a better prediction of gender identity.

Circulating androgens correlate with resting-state MRI in transgender men

Despite mounting evidence regarding the underlying neurobiology in transgender persons, information regarding resting-state activity, particularly after hormonal treatment, is lacking. The present study examined differences between transgender persons on long-term cross-sex hormone therapy and comparisons on two measures of local functional connectivity, intensity of spontaneous resting-state activity (low frequency fluctuations, LFF) and local synchronization of specific brain areas (regional homogeneity, ReHo). Nineteen transgender women (TW, male-to-female), 19 transgender men (TM, female-to-male), 21 non-transgender men (NTM) and 20 non-transgender women (NTW) underwent a resting-state MRI scan. The results showed differences between transgender persons and non-transgender comparisons on both LFF and ReHo measures in the frontal cortex, medial temporal lobe, and cerebellum. More interestingly, circulating androgens correlated for TM in the cerebellum and regions of the frontal cortex, an effect that was associated with treatment duration in the cerebellum. By comparison, no associations were found for TW with estrogens. These data provide first evidence for a potential masculinization of local functional connectivity in hormonally-treated transgender men.

Gender Incongruity in Children With and Without Disorders of Sexual Differentiation

Access to the Internet and recent major media coverage has contributed to an increased societal awareness of the variations of gender identity. There are two sets of clinical guidelines primarily used by practitioners who care for transgender adolescents and adults. Although these guidelines have been tremendously helpful for the management of transgender adolescents, those working in the field recognize the limitations of firm recommendations with a population that is so heterogeneous. This article will summarize current recommendations for the management of children and adolescents with gender incongruence and suggest ways in which we might vary from the current guidelines.