A Review of the Status of Brain Structure Research in Transsexualism

Sex Hormones and Gender Role Relate to Gray Matter Volumes in Sexually Dimorphic Brain Areas

The present study investigates the relationship of circulating sex hormone levels and gender role to gray matter volumes in sexually dimorphic brain areas and explores, whether these relationships are modulated by biological sex (as assigned at birth based on sexual anatomy) or oral contraceptive (OC) use. It was hypothesized that testosterone and masculinity relate positively to gray matter volumes in areas that are typically larger in men, like the hippocampus or cerebellum, while estradiol/progesterone and femininity relate positively to gray matter volumes in the frontal cortex. To that end, high resolution structural MRI scans, sex hormone levels and gender role self-assessments were obtained in a large sample 89 men, 89 naturally cycling (NC) women, and 60 OC users. Men showed larger regional gray matter volumes than women in the cerebellum and bilateral clusters spanning the putamen and parts of the hippocampi/parahippocampi and fusiform gyri. In accordance with our hypotheses, a significant positive association of testosterone to hippocampal volumes was observed in women irrespective of OC use. Participant's self-reported femininity was significantly positively associated with gray matter volumes in the left middle frontal gyrus (MFG) in men. In addition several differences between OC-users and NC women were identified.

Possible Neurobiological Underpinnings of Homosexuality and Gender Dysphoria

Although frequently discussed in terms of sex dimorphism, the neurobiology of sexual orientation and identity is unknown. We report multimodal magnetic resonance imaging data, including cortical thickness (Cth), subcortical volumes, and resting state functional magnetic resonance imaging, from 27 transgender women (TrW), 40 transgender men (TrM), and 80 heterosexual (40 men) and 60 homosexual cisgender controls (30 men). These data show that whereas homosexuality is linked to cerebral sex dimorphism, gender dysphoria primarily involves cerebral networks mediating self-body perception. Among the homosexual cisgender controls, weaker sex dimorphism was found in white matter connections and a partly reversed sex dimorphism in Cth. Similar patterns were detected in transgender persons compared with heterosexual cisgender controls, but the significant clusters disappeared when adding homosexual controls, and correcting for sexual orientation. Instead, both TrW and TrM displayed singular features, showing greater Cth as well as weaker structural and functional connections in the anterior cingulate-precuneus and right occipito-parietal cortex, regions known to process own body perception in the context of self.

The Evolving Role of Pharmacists in Transgender Health Care

Pharmacists are increasingly part of a multifaceted team providing health care to members of the often marginalized transgender (TG) community. Some pharmacists, however, may feel unprepared to care for and interact with TG individuals. By providing comprehensive, respectful, and gender-affirming support, improving physical pharmacy environments with policies and procedures, pharmacists can be trustworthy providers for TG patients. This review focuses primarily on the health issues of TG persons and the pharmacist's role in promoting health, identifying barriers to health care, and providing health care resources for TG persons. The evolution of psychiatric diagnostic criteria, access to health care, and inclusion of TG, lesbian, gay, and bisexual topics in the educational curriculum are presented. Cultural competency and diversity training that addresses gender identity and sexual orientation issues should be important interdisciplinary and interprofessional activities for all health care professional education programs. Pharmacists play a key role in the health care needs of TG persons that include appropriate laboratory monitoring, complex pharmacotherapeutic challenges, and providing unbiased gender-affirming interactions. The pharmacy's physical environment, staff training, and policies and procedures can offer unique services to TG persons.

A comparative study of white matter volume between postoperative female-to-male transsexuals and healthy female

Cross-sex hormones in female-to-male (FtM) transsexuals play a crucial role in brain plasticity. Morphological study associated with white matter (WM) volume in postoperative FtM transsexuals receiving cross-sex hormones has not been published yet. This study was performed to discriminate the regional WM volume differences between postoperative FtM transsexuals and female controls using voxel-based morphometry (VBM) and further to assess the correlations between regional volume variations and cross-sex hormones. WM volume was assessed in 12 postoperative FtM transsexuals receiving cross-sex hormones with 16 age-matched female controls. WM volume was processed using SPM8 software with diffeomorphic anatomical registration via an exponentiated Lie algebra (DARTEL) algorithm. Serum sex hormones, including estriol, free testosterone (free-T), estradiol, follicle-stimulating hormone, and luteinizing hormone were measured. Postoperative FtM transsexuals showed significantly (p < 0.05) larger WM volumes in the inferior parietal lobule, postcentral gyrus, and middle temporal gyrus compared with female controls. However, there were no brain areas with larger WM volume in female controls compared with FtM transsexuals. WM volumes of the inferior parietal lobule and middle temporal gyrus in FtM transsexuals were positively correlated with the levels of free-T. This study revealed WM volume change and its correlation with free-T level in postoperative FtM transsexuals. These findings will improve our understanding of the morphometric changes in FtM transsexuals under cross-sex hormone therapy.

Young Children With Gender Nonconforming Behaviors and Preferences

BACKGROUND

There is growing awareness and exposure in both the medical community and the lay media about the characteristics and complex needs of individuals who believe that their gender identity does not match their birth sex. Despite research and lay publications about teens with gender dysphoria and those who identify as transgender, little guidance is available regarding young (prepubertal) children with questions about their gender identity. Although many terms are used to describe these children, we have chosen to describe them as "gender nonconforming" (GNC).

OBJECTIVE

Primary care and developmental-behavioral pediatric providers are often the first professionals with whom young gender nonconforming children and their families discuss their concerns about their emerging gender identity. It is important, therefore, that pediatric providers be knowledgeable about the dilemmas, conflicts, and choices that are typical of these children and their families to guide them appropriately.

OVERVIEW

In this special article, we present observations, informed by clinical experience, an emerging body of research, and a developmental-behavioral pediatric framework, of the complex needs of prepubertal gender nonconforming children and their families and an approach to their care. The article begins by outlining the cognitive and biological bases for gender identity development, as well as the natural history of gender nonconforming preferences and behaviors. It then sets the context for understanding the care of GNC children as an area in which developmentally sophisticated providers can play a crucial role in support of the complex developmental patterns and need for advocacy in multiple settings among these children.

Research Review: Gender identity in youth: treatment paradigms and controversies

BACKGROUND

Pediatric gender identity has gained increased attention over the past several years in the popular media, political arena, and medical literature. This article reviews terminology in this evolving field, traditional models of gender identity development and their limitations, epidemiology and natural history of cross-gender identification among children and adolescents, co-occurring conditions and behaviors, research into the biological and psychosocial determinants of cross-gender identification, and research into the options regarding and benefits of clinical approaches to gender incongruent youth.

METHODS

Based on a critical review of the extant literature, both theoretical and empirical, that addresses the issue of pediatric gender identity, the authors synthesized what is presently known and what is in need of further research in order to elucidate the developmental trajectory and clinical needs of gender diverse youth.

RESULTS

The field of pediatric gender identity has evolved substantially over the past several years. New research suggests that cross-gender identification is prevalent (approximately 1% of youth). These youth suffer disproportionately high rates of anxiety, depression, and suicidality. Although research into the etiology of cross-gender identification is limited, emerging data have shown that affirmative treatment protocols may improve the high rates of mental health difficulties seen among these patients.

CONCLUSIONS

The field of pediatric gender identity has evolved dramatically. Emerging data suggest that these patients' high rates of anxiety, depression, and suicidality appear to be improved with affirmative protocols, although future longitudinal data are needed.

Molecular basis of Gender Dysphoria: androgen and estrogen receptor interaction

BACKGROUND

Polymorphisms in sex steroid receptors have been associated with transsexualism. However, published replication studies have yielded inconsistent findings, possibly because of a limited sample size and/or the heterogeneity of the transsexual population with respect to the onset of dysphoria and sexual orientation. We assessed the role of androgen receptor (AR), estrogen receptors alpha (ERα) and beta (ERβ), and aromatase (CYP19A1) in two large and homogeneous transsexual male-to-female (MtF) and female-to-male (FtM) populations.

METHODS

The association of each polymorphism with transsexualism was studied with a twofold subject-control analysis: in a homogeneous population of 549 early onset androphilic MtF transsexuals versus 728 male controls, and 425 gynephilic FtMs versus 599 female controls. Associations and interactions were investigated using binary logistic regression.

RESULTS

Our data show that specific allele and genotype combinations of ERβ, ERα and AR are implicated in the genetic basis of transsexualism, and that MtF gender development requires AR, which must be accompanied by ERβ. An inverse allele interaction between ERβ and AR is characteristic of the MtF population: when either of these polymorphisms is short, the other is long. ERβ and ERα are also associated with transsexualism in the FtM population although there was no interaction between the polymorphisms. Our data show that ERβ plays a key role in the typical brain differentiation of humans.

CONCLUSION

ERβ plays a key role in human gender differentiation in males and females.

Sexuality after Male-to-Female Gender Affirmation Surgery

Male-to-Female (MtF) gender affirmation surgery (GAS) comprises the creation of a functional and aesthetic perineogenital complex. This study aimed to evaluate the effect of GAS on sexuality. We retrospectively surveyed all 254 MtF transsexual patients who had undergone GAS with penile inversion vaginoplasty at the Department of Urology, University Hospital Essen, Germany, between 2004 and 2010. In total, we received 119 completed questionnaires after a median of 5.05 years since surgery. Of the study participants, 33.7% reported a heterosexual, 37.6% a lesbian, and 22.8% a bisexual orientation related to the self-perceived gender. Of those who had sexual intercourse, 55.8% rated their orgasms to be more intensive than before, with 20.8% who felt no difference. Most patients were satisfied with the sensitivity of the neoclitoris (73.9%) and with the depth of the neovaginal canal (67.1%). The self-estimated pleasure of sexual activity correlated significantly with neoclitoral sensitivity but not with neovaginal depth. There was a significant correlation between the ease with which patients were able to become sexually aroused and their ability to achieve orgasms. In conclusion, orgasms after surgery were experienced more intensely than before in the majority of women in our cohort and neoclitoral sensitivity seems to contribute to enjoyment of sexual activity to a greater extent than neovaginal depth.

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.

Transitioning Back to Maleness

Thirty-one years after living full time as a woman, a 53-year-old skilled machinist returned to have therapy with me, a psychiatrist, because of a decision to return to living as a man. As our work together continued, I suggested to this would-be published novelist that others might benefit from his experience. This led to his posting an extensive account of his life in September 2016 on Gender Trender. Now living in good mental and physical health as a male, he has given me permission to discuss his initial presentation, my understanding of his motivations, and to reflect on the broader questions that his life rises for the field of transgenderism. This report describes regret, defenses against regret, and a dramatic 3-day catharsis followed by the patient's first loving relationship. He now ironically reflects that he escaped from the sensed inauthenticity of his youthful maleness only to create a felt inauthentic feminine social psychological state. The professional literature about the long-term outcome of the transgendered who do not have surgery is largely nonexistent in English. Anecdotal accounts, however, are readily accessible on the Internet.

Grey and white matter volumes either in treatment-naïve or hormone-treated transgender women: a voxel-based morphometry study

Many previous magnetic resonance imaging (MRI) studies have documented sex differences in brain morphology, but the patterns of sexual brain differences in transgender women - male sex assigned at birth - with a diagnosis of gender dysphoria (TW) have been rarely investigated to date. We acquired T1-weighted MRI data for the following four (n = 80) groups: treatment-naïve TW (TNTW), TW treated with cross-sex hormones for at least one year (TTW), cisgender men, and cisgender women (cisgender individuals as controls). Differences in whole-brain and regional white matter volume and grey matter volume (GMV) were assessed using voxel-based morphometry. We found lower global brain volumes and regional GMVs in a large portion of the posterior-superior frontal cortex in the cisgender women group than in the TTW and cisgender men groups. Additionally, both transgender groups exhibited lower bilateral insular GMVs than the cisgender women group. Our results highlight differences in the insula in both transgender groups; such differences may be characteristic of TW. Furthermore, these alterations in the insula could be related to the neural network of body perception and reflect the distress that accompanies gender dysphoria.

Ethical Concerns About Emerging Treatment Paradigms for Gender Dysphoria

The increasing incidence of requests for medical services to support gender transition for children, adolescents, and adults has consequences for society, governmental institutions, schools, families, health-care professionals, and, of course, patients. The sociological momentum to recognize and accommodate to trans phenomena has posed ethical dilemmas for endocrinologists, mental health professionals, and sexual specialists as they experience within themselves the clash between respect for patient autonomy, beneficence, nonmaleficence, and informed consent. The larger ethical clashes are cultural and therefore political. There is a distinct difference between pronouncements that represent human rights ideals and the reality of clinical observations. Some interpret this clash as a moral issue. This article delves into these tensions and reminds apologists from both passionate camps that clinical science has a rich tradition of resolving controversy through careful follow-up, which is not yet well developed in this arena.

Reduced Luteinizing Hormone Induction Following Estrogen and Progesterone Priming in Female-to-Male Transsexuals

Anatomical studies have suggested that one of the brain structures involved in gender identity is the bed nucleus of the stria terminalis, though this brain structure is probably not the only one to control gender identity. We hypothesized that, if this brain area also affected gonadotropin secretion in humans, transsexual individuals might produce different gonadotropin levels in response to exogenous stimulation. In the present study, we examined whether estrogen combined with progesterone might lead to a change in luteinizing hormone (LH) secretion in female-to-male (FTM) transsexual individuals. We studied female control subjects (n = 9), FTM transsexual subjects (n = 12), and male-to-female (MTF) transsexual subjects (n = 8). Ethinyl estradiol (50 μg/tablet) was administered orally, twice a day, for five consecutive days. After the first blood sampling, progesterone (12.5 mg) was injected intramuscularly. Plasma LH was measured with an immunoradiometric assay. The combination of estrogen and progesterone resulted in increased LH secretion in female control subjects and in MTF subjects, but this increase appeared to be attenuated in FTM transsexual subjects. In fact, the %LH response was significantly reduced in FTM subjects (P < 0.05), but not in MTF subjects (P > 0.5), compared to female control subjects. In addition, the peak time after progesterone injection was significantly delayed in FTM subjects (P < 0.05), but not in MTF subjects (P > 0.5), compared to female control subjects. We then compared subjects according to whether the combination of estrogen and progesterone had a positive (more than 200% increase) or negative (less than 200% increase) effect on LH secretion. A χ² analysis revealed significantly different (P < 0.05) effects on LH secretion between female controls (positive n = 7, negative n = 2) and FTM transsexual subjects (positive n = 4, negative n = 8), but not between female controls and MTF transsexual subjects (positive n = 7, negative n = 1). Thus, LH secretion in response to estrogen- and progesterone priming was attenuated in FTM subjects, but not in MTF subjects, compared to control females. This finding suggested that the brain area related to gender identity in morphological studies might also be involved in the LH secretory response in humans. Thus, altered brain morphology might be correlated to altered function in FTM transsexuals.

Structural connections in the brain in relation to gender identity and sexual orientation

Both transgenderism and homosexuality are facets of human biology, believed to derive from different sexual differentiation of the brain. The two phenomena are, however, fundamentally unalike, despite an increased prevalence of homosexuality among transgender populations. Transgenderism is associated with strong feelings of incongruence between one's physical sex and experienced gender, not reported in homosexual persons. The present study searches to find neural correlates for the respective conditions, using fractional anisotropy (FA) as a measure of white matter connections that has consistently shown sex differences. We compared FA in 40 transgender men (female birth-assigned sex) and 27 transgender women (male birth-assigned sex), with both homosexual (29 male, 30 female) and heterosexual (40 male, 40 female) cisgender controls. Previously reported sex differences in FA were reproduced in cis-heterosexual groups, but were not found among the cis-homosexual groups. After controlling for sexual orientation, the transgender groups showed sex-typical FA-values. The only exception was the right inferior fronto-occipital tract, connecting parietal and frontal brain areas that mediate own body perception. Our findings suggest that the neuroanatomical signature of transgenderism is related to brain areas processing the perception of self and body ownership, whereas homosexuality seems to be associated with less cerebral sexual differentiation.

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.

Altered White Matter and Sensory Response to Bodily Sensation in Female-to-Male Transgender Individuals

While most people take identification with their body for granted, conditions such as phantom limb pain, alien hand syndrome, and xenomelia suggest that the feeling of bodily congruence is constructed and susceptible to alteration. Individuals with xenomelia typically experience one of their limbs as over-present and aversive, leading to a desire to amputate the limb. Similarly, many transgender individuals describe their untreated sexed body parts as incongruent and aversive, and many experience phantom body parts of the sex they identify with (Ramachandran, 2008). This experience may relate to differences in brain representation of the sexed body part, as suggested in xenomelia (McGeoch et al., 2011). We utilized magnetoencephalography imaging to record brain activity during somatosensory stimulation of the breast-a body part that feels incongruent to most presurgical female-to-male (FtM)-identified transgender individuals-and the hand, a body part that feels congruent. We measured the sensory evoked response in right hemisphere somatosensory and body-related brain areas and found significantly reduced activation in the supramarginal gyrus and secondary somatosensory cortex, but increased activation at the temporal pole for chest sensation in the FtM group (N = 8) relative to non-transgender females (N = 8). In addition, we found increased white matter coherence in the supramarginal gyrus and temporal pole and decreased white matter diffusivity in the anterior insula and temporal pole in the FtM group. These findings suggest that dysphoria related to gender-incongruent body parts in FtM individuals may be tied to differences in neural representation of the body and altered white matter connectivity.

Autogynephilia and the Typology of Male-to-Female Transsexualism

Abstract. Sexual scientists have recognized for over a century that biologic males who seek sex reassignment – male-to-female (MtF) transsexuals – are not a homogeneous clinical population but comprise two or more distinct subtypes with different symptoms and developmental trajectories. The most widely used typologies of MtF transsexualism have been based on sexual orientation and have distinguished between persons who are androphilic (exclusively sexually attracted to males) and those who are nonandrophilic (sexually attracted to females, both males and females, or neither gender). In 1989, psychologist Ray Blanchard proposed that most nonandrophilic MtF transsexuals display a paraphilic sexual orientation called autogynephilia, defined as the propensity to be sexually aroused by the thought or image of oneself as a woman. Studies conducted by Blanchard and colleagues provided empirical support for this proposal, leading to the hypothesis that almost all nonandrophilic MtF transsexuals are autogynephilic, whereas almost all androphilic MtF transsexuals are not. Blanchard’s ideas received increased attention in 2003 after they were discussed in a book by psychologist J. Michael Bailey. The concept of autogynephilia subsequently became intensely controversial among researchers, clinicians, and MtF transsexuals themselves, causing widespread repercussions. This article reviews the theory of autogynephilia, the evidence supporting it, the objections raised by its critics, and the implications of the resulting controversy for research and clinical care.

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.