What has sex got to do with it? The role of hormones in the transgender brain

Exploring the Impact of Sex and Gender in Brain Function: Implications and Considerations

INTRODUCTION

Sex and gender are crucial variables in understanding brain development and disease. Biological sex is determined by genetic and hormonal factors, whereas gender is a multidimensional construct shaped by social and cultural influences. The interplay of these factors contributes to sex-specific susceptibilities and disease progression in psychiatric and neurological disorders. However, sex and gender are often considered as a single variable, which can lead to biased data analysis and interpretation. This commentary aims to analyze how sex and gender influence brain structure and function, with implications for personalized medicine, research, and the development of gender-sensitive clinical guidelines.

METHODS

Findings from various studies employing neuroimaging techniques and animal models are discussed, as well as the impact of biological sex, gender, environmental, cultural, and social factors on brain development, organization, and behavior.

RESULTS

Evidence suggests that sex differences in brain structure and function are not only genetically determined but are also influenced by gender-related experiences and societal contexts. Importantly, discrepancies between male and female brains are reduced in gender-equal societies. Preclinical studies play a pivotal role in determining the influence of biological sex, independent of gender, in different disease models.

CONCLUSION

The findings underscore the need to consider both sex and gender in research and clinical practice to avoid biases and promote equitable health outcomes. Moving forward, we advocate for gender-sensitive approaches to be integrated into brain research and in clinical guidelines to achieve personalized and precision medicine.

Diagnostic assessment of autism spectrum disorder in transgender and gender diverse youth

Objective: Higher prevalence of autism spectrum disorder (ASD) diagnosis and associated traits has been observed among transgender and gender diverse (TGD) youth, and the number of TGD youth requesting evaluation for autism is growing. This study explored the demographic and clinical profiles of TGD youth evaluated in a specialty autism clinic. Method: Retrospective autism evaluation results for 41 TGD youth aged 5-18 years and 67 cisgender-matched controls were included in the study. Results: Approximately, half of TGD youth were diagnosed with autism (TGDASD+; n = 19 vs. TGDASD-; n = 22). There were no group differences in sex assigned at birth, gender identity, FSIQ, race, or ethnicity. Compared to TGDASD- (allistic) youth, TGD autistics had significantly lower adaptive functioning and were more likely to have an IEP eligibility of ASD. Anxiety and mood disorders were more common in TGD youth, whereas language disorders were more prevalent in cisgender controls. Attention-Deficit/Hyperactivity Disorder (ADHD) was more common among TGDASD- youth (72%) than TGDASD+ youth (47%), though not significantly. Conclusions: TGD youth with school-based IEP eligibilities of ASD and lower adaptive functioning are more likely to be diagnosed with ASD upon medical evaluation. The combination of identifying as TGD and having ADHD may heighten suspicion for ASD. Asking about gender identity during autism evaluations for children middle school-aged and older is recommended.

Effects of L-Dopa, SKF-38393, and quinpirole on exploratory, anxiety- and depressive-like behaviors in pubertal female and male mice

Adolescence is a phase of substantial changes in the brain, characterized by maturational remodeling of many systems. This remodeling allows functional plasticity to adapt to a changing environment. The dopaminergic system is under morphological and physiological changes during this phase. In the present study, we investigated if changes in the dopaminergic tone alter mice behavior in a receptor and sex-specific manner, specifically at the beginning of the puberty period. We administered L-Dopa, SKF-38393 (D1 dopamine receptor agonist), and Quinpirole (D2 dopamine receptor agonist) and tested male and female mice's motor, anxiety- and depressive-like behavior. While females displayed an impaired exploratory drive, males presented an intense depressive-like response. Our results provide insights into the function of dopaminergic development in adolescent behavior and highlight the importance of studies in this time window with male and female subjects.

Early Female Transgender Identity after Prenatal Exposure to Diethylstilbestrol: Report from a French National Diethylstilbestrol (DES) Cohort

Diagnostic of transsexualism and gender incongruence are terms to describe individuals whose self-identity does not match their sex assignment at birth. A transgender woman is an individual assigned male at birth (AMAB) on the basis of the external or internal genitalia who identifies and lives as a woman. In recent decades, a significant increase in the number of transgender people has been reported. Although, its etiology is unknown, biological, anatomical, genetic, environmental and cultural factors have been suggested to contribute to gender variation. In XY animals, it has been shown that environmental endocrine disruptors, through their anti-androgenic activity, induce a female identity. In this work, we described four XY individuals who were exposed in utero to the xenoestrogen diethylstilbesterol (DES) and were part of the French HHORAGES cohort. They all reported a female transgender identity starting from childhood and adolescence. This high prevalence of male to female transgenderism (1.58%) in our cohort of 253 DES sons suggests that exposure to chemicals with xenoestrogen activity during fetal life may affect the male sex identity and behavior.

Sex and gender correlates of sexually polymorphic cognition

BACKGROUND

Sexually polymorphic cognition (SPC) results from the interaction between biological (birth-assigned sex (BAS), sex hormones) and socio-cultural (gender identity, gender roles, sexual orientation) factors. The literature remains quite mixed regarding the magnitude of the effects of these variables. This project used a battery of classic cognitive tests designed to assess the influence of sex hormones on cognitive performance. At the same time, we aimed to assess the inter-related and respective effects that BAS, sex hormones, and gender-related factors have on SPC.

METHODS

We recruited 222 adults who completed eight cognitive tasks that assessed a variety of cognitive domains during a 150-min session. Subgroups were separated based on gender identity and sexual orientation and recruited as follows: cisgender heterosexual men (n = 46), cisgender non-heterosexual men (n = 36), cisgender heterosexual women (n = 36), cisgender non-heterosexual women (n = 38), gender diverse (n = 66). Saliva samples were collected before, during, and after the test to assess testosterone, estradiol, progesterone, cortisol, and dehydroepiandrosterone. Psychosocial variables were derived from self-report questionnaires.

RESULTS

Cognitive performance reflects sex and gender differences that are partially consistent with the literature. Interestingly, biological factors seem to better explain differences in male-typed cognitive tasks (i.e., spatial), while psychosocial factors seem to better explain differences in female-typed cognitive tasks (i.e., verbal).

CONCLUSION

Our results establish a better comprehension of SPC over and above the effects of BAS as a binary variable. We highlight the importance of treating sex as a biological factor and gender as a socio-cultural factor together since they collectively influence SPC.

Nutrition and Health in the Lesbian, Gay, Bisexual, Transgender, Queer/Questioning Community: A Narrative Review

Sexual and gender minorities have a higher risk for health and nutrition-related disparities across the life course compared to the heterosexual or cisgender population. Experiences of stigmatization and discrimination are associated with diminished mental health quality and psychological distress, which are risk factors for developing various eating disorders. Other nutrition disparities include increased risk for food insecurity, body dissatisfaction, and weight complications, such as those experienced by the transgender population in association with gender-affirming hormone therapies. Despite the need for tailored nutrition recommendations that address the unique needs of the lesbian, gay, bisexual, transgender, queer/questioning (LGBTQ+) community, there are currently no such guidelines in North America. The purpose of this review is to summarize major LGBTQ+ nutrition disparities and highlight the need for tailored recommendations. We examine the evidence on mental health and social disparities in this group, including vulnerabilities to disordered eating, food insecurity, and healthcare provider discrimination. Importantly, we identify a scarcity of literature on dietary concerns and nutrition care guidelines for LGBTQ+ groups, including studies that address intersectionality and differences among specific gender and sexual orientations. These gaps underline the urgency of prioritizing nutrition for LGBTQ+ health needs and for developing tailored public health nutrition recommendations for this underserved population. Our review suggests that future LGBTQ+ health and nutrition research agendas should include personalized and precision nutrition, social determinants of health, diet quality, body image, and healthcare provider cultural competency and responsiveness. Moreover, the current evidence on LGBTQ+ nutrition and health will be strengthened when research studies (including clinical trials) with robust methodologies amplify inclusion and representation of this community to elucidate health and nutrition disparities in sexual and gender minorities.

Executive functions in adolescents with gender dysphoria

Aim: Aim of this study is evaluating EF by performing neurocognitive tests, and to identify gender-related differences in EF between adolescents with and without GD.Methods: 8 Female-to-Male transgender adolescents (FtMs), and 14 Male-to-Female transsexual adolescents (MtFs) (Gender Dysphoria Group, GDG) and 29 boys, 21 girls (Control Group, CG), were tested in a cross-sectional study, using the Wisconsin Card Sorting Test (WCST), Controlled Oral Word Association Test (COWAT), and Stroop Color and Word Test (SCWT). The psychiatric diagnoses were established by using the KD-SADS.Results: Among GDG 72.7%, had at least one psychopathology. There weren't any significant differences in, estimated IQ scores, or WCST subtest scores between the 2 groups. COWAT total word count and SCWT-5 total duration test scores were better in the CG.Conclusion: CG had better performance on verbal fluency and response inhibition whereas no differences found on set shifting abilities. In consideration of the existence of EF-related impairment in adolescents with GD, appropriate support and interventions are expected to improve their adaptation skills and comorbid psychopathologies. These results should be interprete cautiously and additional larger scale studies are needed to obtain more comprehensive data related to gender differences in EF of adolescents with GD.

A systematic review of psychosocial functioning changes after gender-affirming hormone therapy among transgender people

This systematic review assessed the state and quality of evidence for effects of gender-affirming hormone therapy on psychosocial functioning. Forty-six relevant journal articles (six qualitative, 21 cross-sectional, 19 prospective cohort) were identified. Gender-affirming hormone therapy was consistently found to reduce depressive symptoms and psychological distress. Evidence for quality of life was inconsistent, with some trends suggesting improvements. There was some evidence of affective changes differing for those on masculinizing versus feminizing hormone therapy. Results for self-mastery effects were ambiguous, with some studies suggesting greater anger expression, particularly among those on masculinizing hormone therapy, but no increase in anger intensity. There were some trends toward positive change in interpersonal functioning. Overall, risk of bias was highly variable between studies. Small samples and lack of adjustment for key confounders limited causal inferences. More high-quality evidence for psychosocial effects of gender-affirming hormone therapy is vital for ensuring health equity for transgender people.

Alterations in the inferior fronto-occipital fasciculus - a specific neural correlate of gender incongruence?

BACKGROUND

Increasing numbers of adolescents seek help for gender-identity questions. Consequently, requests for medical treatments, such as puberty suppression, are growing. However, studies investigating the neurobiological substrate of gender incongruence (when birth-assigned sex and gender identity do not align) are scarce, and knowledge about the effects of puberty suppression on the developing brain of transgender youth is limited.

METHODS

Here we cross-sectionally investigated sex and gender differences in regional fractional anisotropy (FA) as measured by diffusion MR imaging, and the impact of puberty on alterations in the white-matter organization of 35 treatment-naive prepubertal children and 41 adolescents with gender incongruence, receiving puberty suppression. The transgender groups were compared with 79 age-matched, treatment-naive cisgender (when sex and gender align) peers.

RESULTS

We found that transgender adolescents had lower FA in the bilateral inferior fronto-occipital fasciculus (IFOF), forceps major and corpus callosum than cisgender peers. In addition, average FA values of the right IFOF correlated negatively with adolescents' cumulative dosage of puberty suppressants received. Of note, prepubertal children also showed significant FA group differences in, again, the right IFOF and left cortico-spinal tract, but with the reverse pattern (transgender > cisgender) than was seen in adolescents.

CONCLUSIONS

Importantly, our results of lower FA (indexing less longitudinal organization, fiber coherence, and myelination) in the IFOF of gender-incongruent adolescents replicate prior findings in transgender adults, suggesting a salient neural correlate of gender incongruence. Findings highlight the complexity with which (pubertal) sex hormones impact white-matter development and add important insight into the neurobiological substrate associated with gender incongruence.

Transgender Health Care Primer for Clinical Audiologists

PURPOSE

Transgender people have been increasingly visible in society. Recent research has indicated that millions of Americans, 0.7% of the total population, identify as transgender. Although transgender people experience all the same auditory and vestibular disorders as people who are not transgender, there is a dearth of information about transgender issues in audiology graduate education and continuing education. The author discusses their positionality as a transgender audiologist and provides guidance on working with transgender patients from their experience and from the published literature.

CONCLUSION

This tutorial provides an overview of transgender identity for clinical audiologists and summarizes the social, legal, and medical landscape of transgender identity as it relates to audiology.

Headache prevalence in transgender and gender diverse youth: A single-center case-control study

OBJECTIVE

Assess the prevalence of headache in transgender and gender-diverse adolescents, comparing prevalence with and without exposure to gender-affirming hormone therapy.

BACKGROUND

Transgender and gender-diverse youth are an understudied group in whom we can study the effects of sex steroids on adolescents' development of headache. We hypothesized that transfeminine adolescents treated with estrogen would have higher odds of headache than those not treated, and that transmasculine adolescents treated with testosterone would have lower odds of headache than those not treated.

METHODS

This retrospective case-control study analyzed all patients seen at the Boston Children's Hospital Gender Multispecialty Service clinic from 2007 to 2017. Cases were defined as patients with headache, controls as those without headache, and exposure as treatment with gender-affirming hormone therapy (i.e., estrogen or testosterone). A computerized search identified cases that were then validated by chart review.

RESULTS

Fifty-two of the 763 transgender and gender-diverse patients seen were confirmed to have headache. Of 273 transfeminine patients 45% (123/273) received estrogen treatment. Transfeminine patients receiving estrogen were more likely to have headache than those not receiving estrogen (7% [9/123] vs. 1% [2/150]; odd ratio [OR] 5.84 (95% confidence interval [CI] 1.24-27.6), p = 0.026). Of 490 transmasculine patients, 46% (227/490) received testosterone. Transmasculine patients receiving testosterone were more likely to have headache than those not receiving testosterone (12% [28/227] vs. 5% (13/263); OR 2.71 (95% CI 1.37-5.4), p = 0.005).

CONCLUSION

Among transfeminine and transmasculine youth, those who received gender-affirming hormone therapy had higher odds of headache compared to those not taking gender-affirming hormone therapy. Further prospective studies to guide headache care of transgender and gender-diverse youth and adults are needed. Our results could be generalizable to other pediatric gender management clinics and may be worth discussing with patients considering treatment.

Sex differences in neuroimmunoendocrine communication. Involvement on longevity

Endocrine, nervous, and immune systems work coordinately to maintain the global homeostasis of the organism. They show sex differences in their functions that, in turn, contribute to sex differences beyond reproductive function. Females display a better control of the energetic metabolism and improved neuroprotection and have more antioxidant defenses and a better inflammatory status than males, which is associated with a more robust immune response than that of males. These differences are present from the early stages of life, being more relevant in adulthood and influencing the aging trajectory in each sex and may contribute to the different life lifespan between sexes.

Cognitive Development and Prenatal Air Pollution Exposure in the CHAMACOS Cohort

BACKGROUND

Because fine particulate matter [PM, with aerodynamic diameter ≤ 2.5 μ m (PM 2.5 )] is a ubiquitous environmental exposure, small changes in cognition associated with PM 2.5 exposure could have great societal costs. Prior studies have demonstrated a relationship between in utero PM 2.5 exposure and cognitive development in urban populations, but it is not known whether these effects are similar in rural populations and whether they persist into late childhood.

OBJECTIVES

In this study, we tested for associations between prenatal PM 2.5 exposure and both full-scale and subscale measures of IQ among a longitudinal cohort at age 10.5 y.

METHODS

This analysis used data from 568 children enrolled in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS), a birth cohort study in California's agricultural Salinas Valley. Exposures were estimated at residential addresses during pregnancy using state of the art, modeled PM 2.5 surfaces. IQ testing was performed by bilingual psychometricians in the dominant language of the child.

RESULTS

A 3 - μ g / m 3 higher average PM 2.5 over pregnancy was associated with - 1.79 full-scale IQ points [95% confidence interval (CI): - 2.98 , - 0.58 ], with decrements specifically in Working Memory IQ (WMIQ) and Processing Speed IQ (PSIQ) subscales [WMIQ - 1.72 (95% CI: - 2.98 , - 0.45 ) and PSIQ - 1.19 (95% CI: - 2.54 , 0.16)]. Flexible modeling over the course of pregnancy illustrated mid-to-late pregnancy (months 5-7) as particularly susceptible times, with sex differences in the timing of susceptible windows and in which subscales were most affected [Verbal Comprehension IQ (VCIQ) and WMIQ in males; and PSIQ in females].

DISCUSSION

We found that small increases in outdoor PM 2.5 exposure in utero were associated with slightly lower IQ in late childhood, robust to many sensitivity analyses. In this cohort there was a larger effect of PM 2.5 on childhood IQ than has previously been observed, perhaps due to differences in PM composition or because developmental disruption could alter the cognitive trajectory and thus appear more pronounced as children get older. https://doi.org/10.1289/EHP10812.

Concordance for Gender Dysphoria in Genetic Female Monozygotic (Identical) Triplets

The biopsychosocial etiology of gender dysphoria is poorly understood, but current thought suggests a complex interaction of genetic, hormonal, environmental, and differences in brain development and physiology. Twin studies have implicated a genetic role in the formation of gender identity. Congruence for gender dysphoria is more common among monozygotic twins compared to dizygotic twins. We present a case of monozygotic (identical) triplets who have each transitioned from female to male under the care of a university transgender health service. Each triplet experienced gender dysphoria from childhood and has undergone transitional endocrine care and various aspects of gender-affirming surgery. Although a pure genetic or biological component cannot be attributed as a cause of their gender dysphoria with absolute certainty since the triplets were raised together, this unusual case of gender dysphoria among a set of monozygotic triplets adds support for a heritable role in gender identity formation.

Gender dysphoria in twins: a register-based population study

Both genetic and environmental influences have been proposed to contribute to the variance of gender identity and development of gender dysphoria (GD), but the magnitude of the effect of each component remains unclear. We aimed to examine the prevalence of GD among twins and non-twin siblings of individuals with GD, using data derived from a large register-based population in Sweden over the period 2001-2016. Register data was collected from the Statistics Sweden and the National Board of Health and Welfare. The outcome of interest was defined as at least four diagnoses of GD or at least one diagnosis followed by gender-affirming treatment. A total of 2592 full siblings to GD cases were registered, of which 67 were twins; age at first GD diagnosis for the probands ranged from 11.2 to 64.2 years. No same-sex twins that both presented with GD were identified during the study period. The proportion of different-sex twins both presenting with GD (37%) was higher than that in same-sex twins (0%, Fisher's exact test p-value < 0.001) and in non-twin sibling pairs (0.16%). The present findings suggest that familial factors, mainly confined to shared environmental influences during the intrauterine period, seem to contribute to the development of GD.

Inter-Network Brain Functional Connectivity in Adolescents Assigned Female at Birth Who Experience Gender Dysphoria

Gender dysphoria (GD) is characterized by distress due to an incongruence between experienced gender and sex assigned at birth. Brain functional connectivity in adolescents who experience GD may be associated with experienced gender (vs. assigned sex) and/or brain networks implicated in own-body perception. Furthermore, sexual orientation may be related to brain functional organization given commonalities in developmental mechanisms proposed to underpin GD and same-sex attractions. Here, we applied group independent component analysis to resting-state functional magnetic resonance imaging (rs-fMRI) BOLD timeseries data to estimate inter-network (i.e., between independent components) timeseries correlations, representing functional connectivity, in 17 GD adolescents assigned female at birth (AFAB) not receiving gender-affirming hormone therapy, 17 cisgender girls, and 15 cisgender boys (ages 12-17 years). Sexual orientation was represented by degree of androphilia-gynephilia and sexual attractions strength. Multivariate partial least squares analyses found that functional connectivity differed among cisgender boys, cisgender girls, and GD AFAB, with the largest difference between cisgender boys and GD AFAB. Regarding sexual orientation and age, the brain's intrinsic functional organization of GD AFAB was both similar to and different from cisgender girls, and both differed from cisgender boys. The pattern of group differences and the networks involved aligned with the hypothesis that brain functional organization is different among GD AFAB (vs. cisgender) adolescents, and certain aspects of this organization relate to brain areas implicated in own-body perception and self-referential thinking. Overall, brain functional organization of GD AFAB was generally more similar to that of cisgender girls than cisgender boys.

'That Time of the Month' - Investigating the Influence of the Menstrual Cycle and Oral Contraceptives on the Brain Using Magnetic Resonance Imaging

The stereotypic and oversimplified relationship between female sex hormones and undesirable behavior dates to the earliest days of human society, as already the ancient Greek word for the uterus, "hystera" indicated an aversive connection. Remaining and evolving throughout the centuries, transcending across cultures and various aspects of everyday life, its perception was only recently reframed. Contemporarily, the complex interaction of hormonal phases (i. e., the menstrual cycle), hormonal medication (i. e., oral contraceptives), women's psychological well-being, and behavior is the subject of multifaceted and more reflected discussions. A driving force of this ongoing paradigm shift was the introduction of this highly interesting and important topic into the realm of scientific research. This refers to neuroscientific research as it enables a multimodal approach combining aspects of physiology, medicine, and psychology. Here a growing body of literature points towards significant alterations of both brain function, such as lateralization of cognitive functions, and structure, such as gray matter concentrations, due to fluctuations and changes in hormonal levels. This especially concerns female sex hormones. However, the more research is conducted within this field, the less reliable these observations and derived insights appear. This may be due to two particular factors: measurement inconsistencies and diverse hormonal phases accompanied by interindividual differences. The first factor refers to the prominent unreliability of one of the primarily utilized neuroscientific research instruments: functional magnetic resonance imaging (fMRI). This unreliability is seemingly present in paradigms and analyses, and their interplay, and is additionally affected by the second factor. In more detail, hormonal phases and levels further influence neuroscientific results obtained through fMRI as outcomes vary drastically across different cycle phases and medication. This resulting vast uncertainty thus tremendously hinders the further advancement of our understanding of how female sex hormones might alter brain structure and function and, ultimately, behavior.This review summarizes parts of the current state of research and outlines the essential requirements to further investigate and understand the female brain's underlying physiological and anatomical features.

Protective effect of estradiol copreservation against kidney ischemia-reperfusion injury

Ischemia-reperfusion injury (IRI) is the major cause of delayed graft function (DGF) during the posttransplantation period. Estradiol (E2) prevents IRI-induced kidney dysfunction and tissue injury. However, many side effects limit E2's in vivo application. Recent evidence uncovers E2's expanded use in the field of transplantation. We aimed to study if and how E2 exerts protective activity during the period of kidney organ preservation. The autologous kidney transplant model in rats was first established. Rats were divided into 5 groups: normal group (N), sham group (sham), static cold storage (SCS) 4 hours group (control), SCS 4 hours + ethanol (1 µL/mL) group (solvent), and SCS 4 hours + ethanol (1 µL/mL) + E2 (1000 ng/mL) group (E2). ERα expression under hypothermia was measured by western blotting. Moreover, biochemical analyses of plasma levels of creatinine, BUN, estradiol, and testosterone were examined. Among all groups, kidney tissues were collected and processed for further western blot analysis about ERα, eNOS, Bcl-2, and Bax expression, histological analyses such as H&E staining to evaluate pathological severity. In addition, a TUNEL assay is performed to evaluate apoptosis. E2 copreservation upregulated ERα expression under hypothermia. Moreover, E2 copreservation reduced levels of creatinine and BUN in plasma but without affecting estradiol and testosterone. Further, E2 copreservation increased expression of eNOS and antiapoptotic Bcl-2 and decreases expression of proapoptotic Bax. E2 copreservation significantly inhibited IRI-induced apoptosis and evidently improved pathological severity in the kidney of rats. E2 copreservation exerts protective activity against IRI-induced pro-inflammatory and proapoptotic effects in kidneys during organ preservation time and improves transplanted kidney function.

Recommendations to Address the Unique Clinical and Psychological Needs of Transgender Persons Living With Multiple Sclerosis

BACKGROUND

People living with multiple sclerosis (MS) face challenges coping with chronic illnesses, and transgender (TGD) persons living with MS may experience additional unique challenges and barriers to care. Medical biases toward TGD people are widely reported, and best practices in TGD MS care have not been identified.

METHODS

A case report of a TGD person living with MS is reviewed that helped to identify and inform us regarding the unique aspects of their clinical and psychological care needs. We conducted a systematic review of the literature according to the standard methods in PubMed. The literature was reviewed and summarized for relevant topics related to the unique care needs of TGD persons living with MS, and proposed care recommendations were created.

RESULTS

We used the aforementioned case to identify and inform the special care needs and subsequently describe proposed recommendations to achieve inclusive comprehensive care of TGD persons with MS. The importance of providing an inclusive environment, comprehensive care, mental health screening, domestic violence screening, and case coordination are highlighted with the goal of providing best practice recommendations for the comprehensive inclusive care of TGD persons living with MS.

CONCLUSIONS

The lack of published guidance on the care of TGD persons living with MS and our informative case have led to the proposed recommendations for the care of TGD persons living with MS.

Flexibility in autism during unpredictable shifts of socio-emotional stimuli: Investigation of group and sex differences

LAY ABSTRACT

Flexibility difficulties in autism might be particularly common in complex situations, when shifts (i.e. the switch of attentional resources or strategy according to the situation) are unpredictable, implicit (i.e. not guided by explicit rules) and the stimuli are complex. We analyzed the data of 101 autistic and 145 non-autistic adults, without intellectual deficiency, on two flexibility tasks performed online. The first task involved unpredictable and non-explicit shifts of complex socio-emotional stimuli, whereas the second task involved predictable and explicit shifts of character stimuli. Considering the discrepancies between laboratory results and the real-life flexibility-related challenges faced by autistic individuals, we need to determine which factor could be of particular importance in flexibility difficulties. We point out that the switch cost (i.e. the difference between shift and non-shift condition) was larger for autistic than for non-autistic participants on the complex flexibility task with unpredictable and non-explicit shifts of socio-emotional stimuli, whereas this was not the case when shifts were predictable, explicit and involved less complex stimuli. We also highlight sex differences, suggesting that autistic females have better social skills than autistic males and that they also have a specific cognitive profile, which could contribute to social camouflaging. The findings of this work help us understand which factors could influence flexibility difficulties in autism and are important for designing future studies. They also add to the literature on sex differences in autism which underpin better social skills, executive function, and camouflaging in autistic females.

LGBTQIA+ invisibility in nursing anatomy/physiology textbooks

Members of the LGBTQIA+ experience health disparities that are compounded by providers that lack cultural competence, i.e., the skills, attitudes, and knowledge to offer culturally sensitive care. Educational efforts focus on increasing LGBTQIA+ representation across undergraduate nursing curricula and the recruitment and retention of members of this community into nursing programs. However, the ways that classroom materials represent LGBTQIA+ people can perpetuate social norms rather than accurate scientific understandings, thus limiting students' development of cultural competence while also driving LGBTQIA+ students from nursing. This study performs a content analysis for LGBTQIA+ inclusion in four widely adopted undergraduate nursing anatomy/physiology textbooks. We identify specific social beliefs that exclude LGBTQIA+ people and compare the different ways these manifested in each of the four textbooks. We argue that the way these books represent LGBTQIA+ people violate the fundamental ethical principles of nursing. Based on our findings, we challenge educators to consider the impact that language, images, and other classroom materials have on LGBTQIA+ students and all students' ability to develop cultural competence.

High spatial frequency filtered primes hastens happy faces categorization in autistic adults

Coarse information of a visual stimulus is conveyed by Low Spatial Frequencies (LSF) and is thought to be rapidly extracted to generate predictions. This may guide fast recognition with the subsequent integration of fine information, conveyed by High Spatial Frequencies (HSF). In autism, emotional face recognition is challenging, and might be related to alterations in LSF predictive processes. We analyzed the data of 27 autistic and 34 non autistic (NA) adults on an emotional Stroop task (i.e., emotional face with congruent or incongruent emotional word) with spatially filtered primes (HSF vs.LSF). We hypothesized that LSF primes would generate predictions leading to faster categorization of the target face compared to HSF primes, in the NA group but not in autism. Surprisingly, HSF primes led to faster categorization than LSF primes in both groups. Moreover, the advantage of HSF vs.LSF primes was stronger for angry than happy faces in NA, but was stronger for happy than angry faces in autistic participants. Drift diffusion modelling confirmed HSF advantage and showed a longer non-decision time (e.g., encoding) in autism. Despite LSF predictive impairments in autism was not corroborated, our analyses suggest low level processing specificities in autism.

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).

Challenging the binary: Gender/sex and the bio-logics of normalcy

BACKGROUND

We are witnessing renewed debates regarding definitions and boundaries of human gender/sex, where lines of genetics, gonadal hormones, and secondary sex characteristics are drawn to defend strict binary categorizations, with attendant implications for the acceptability and limits of gender identity and diversity.

AIMS

Many argue for the need to recognize the entanglement of gender/sex in humans and the myriad ways that gender experience becomes biology; translating this theory into practice in human biology research is essential. Biological anthropology is well poised to contribute to these societal conversations and debates. To do this effectively, a reconsideration of our own conceptions of gender/sex, gender identity, and sexuality is necessary.

METHODS

In this article, we discuss biological variation associated with gender/sex and propose ways forward to ensure we are engaging with gender/sex diversity. We base our analysis in the concept of "biological normalcy," which allows consideration of the relationships between statistical distributions and normative views. We address the problematic reliance on binary categories, the utilization of group means to represent typical biologies, and document ways in which binary norms reinforce stigma and inequality regarding gender/sex, gender identity, and sexuality.

DISCUSSION AND CONCLUSIONS

We conclude with guidelines and methodological suggestions for how to engage gender/sex and gender identity in research. Our goal is to contribute a framework that all human biologists can use, not just those who work with gender or sexually diverse populations. We hope that in bringing this perspective to bear in human biology, that novel ideas and applications will emerge from within our own discipline.

Implications of the Estrogen Receptor Coactivators SRC1 and SRC2 in the Biological Basis of Gender Incongruence

Introduction

Brain sexual differentiation results from the effects of sex steroids on the developing brain. The presumptive route for brain masculinization is the direct induction of gene expression via activation of the estrogen receptors α and β and the androgen receptor through their binding to ligands and to coactivators, regulating the transcription of multiple genes in a cascade effect.

Aim

To analyze the implication of the estrogen receptor coactivators SRC-1, SRC-2, and SRC-3 in the genetic basis of gender incongruence.

Main Outcome Measures

Analysis of 157 polymorphisms located at the estrogen receptor coactivators SRC-1, SRC-2, and SRC-3, in 94 transgender versus 94 cisgender individuals.

Method

Using SNPStats software, the allele and genotype frequencies were analyzed by χ2, the strength of the association was measured by binary logistic regression, estimating the odds ratio for each genotype. Measurements of linkage disequilibrium and haplotype frequencies were also performed.

Results

We found significant differences at level P < .05 in 8 polymorphisms that correspond to 5.09% of the total. Three were located in SRC-1 and 5 in SRC-2. The odds ratio analysis showed significant differences at level P < .05 for multiple patterns of inheritance. The polymorphisms analyzed were in linkage disequilibrium. The SRC-1 haplotypes CGA and CGG (global haplotype association P < .009) and the SRC-2 haplotypes GGTAA and GGTAG (global haplotype association P < .005) were overrepresented in the transgender population.

Conclusion

The coactivators SRC-1 and SRC-2 could be considered as candidates for increasing the list of potential genes for gender incongruence. Ramírez KDV, Fernández R, Delgado-Zayas E, et al. Implications of the Estrogen Receptor Coactivators SRC1 and SRC2 in the Biological Basis of Gender Incongruence. Sex Med 2021;9:100368.

The role of androgens in clitorophallus development and possible applications to transgender patients

BACKGROUND

The clitorophallus, or glans, is a critical structure in sexual development and plays an important role in how gender is conceptualized across the life span. This can be seen in both the evaluation and treatment of intersex individuals and the use of gender-affirming masculinizing therapies to help those born with a clitoris (small clitorophallus with separate urethra) enlarge or alter the function of that structure.

OBJECTIVES

To review the role of testosterone in clitorophallus development from embryo to adulthood, including how exogenous testosterone is used to stimulate clitorophallus enlargement in masculinizing gender-affirming therapy.

MATERIALS AND METHODS

Relevant English-language literature was identified and evaluated for data regarding clitorophallus development in endosex and intersex individuals and the utilization of hormonal and surgical masculinizing therapies on the clitorophallus. Studies included evaluated the spectrum of terms regarding the clitorophallus (genital tubercle, clitoris, micropenis, penis).

RESULTS

Endogenous testosterone, and its more active metabolite dihydrotestosterone, plays an important role in the development of the genital tubercle into the clitorophallus, primarily during the prenatal and early postnatal periods and then again during puberty. Androgens contribute to not only growth but also the inclusion of a urethra on the ventral aspect. Exogenous testosterone can be used to enlarge the small clitorophallus (clitoris or micropenis) as part of both intersex and gender-affirming care (in transmasculine patients, up to 2 cm of additional growth). Where testosterone is insufficient to provide the degree of masculinization desired, surgical options including phalloplasty and metoidioplasty are available.

DISCUSSION AND CONCLUSION

Endogenous testosterone plays an important role in clitorophallus development, and there are circumstances where exogenous testosterone may be useful for masculinization. Surgical options may also help some patients reach their personal goals. As masculinizing gender-affirming care advances, the options available for clitorophallus modifications will likely continue to expand and improve.

Risk and Resilience Factors for Mental Health among Transgender and Gender Nonconforming (TGNC) Youth: A Systematic Review

In recent years, there has been a proliferation of research regarding transgender and gender nonconforming (TGNC) people. The stigma and legal discriminations that this population faces have obvious and documented repercussions for mental health. In 2015, the American Psychological Association (APA) published Guidelines for Psychological Practice with TGNC People. The APA noted that due to the nuances of working with TGNC youth and the dearth of related literature, the guidelines focus primarily on TGNC adults. To date, there has not been a systematic review of risk and resilience factors for mental health among TGNC children, adolescents, and young adults under the age of 25. Forty-four peer-reviewed articles met inclusion criteria for this systematic review, and were evaluated for their methodological rigor and their findings. Common risk factors for negative mental health variables included physical and verbal abuse, exposure to discrimination, social isolation, poor peer relations, low self-esteem, weight dissatisfaction, and age. Across studies, older children and adolescents tended to report higher rates of psychological distress. Resilience-promoting factors for mental health were also documented, including parent connectedness, social support, school safety and belonging, and the ability to use one's chosen name. By synthesizing the existing literature using a resilience-focused and minority stress framework, the present review provides clinicians and researchers with a coherent evidence-base to better equip them to promote psychological adaptation and wellbeing among TGNC youth.

A Multi-Modal MRI Analysis of Cortical Structure in Relation to Gender Dysphoria, Sexual Orientation, and Age in Adolescents

Gender dysphoria (GD) is characterized by distress due to an incongruence between experienced gender and sex assigned at birth. Sex-differentiated brain regions are hypothesized to reflect the experienced gender in GD and may play a role in sexual orientation development. Magnetic resonance brain images were acquired from 16 GD adolescents assigned female at birth (AFAB) not receiving hormone therapy, 17 cisgender girls, and 14 cisgender boys (ages 12–17 years) to examine three morphological and microstructural gray matter features in 76 brain regions: surface area (SA), cortical thickness (CT), and T1 relaxation time. Sexual orientation was represented by degree of androphilia-gynephilia and sexual attraction strength. Multivariate analyses found that cisgender boys had larger SA than cisgender girls and GD AFAB. Shorter T1, reflecting denser, macromolecule-rich tissue, correlated with older age and stronger gynephilia in cisgender boys and GD AFAB, and with stronger attractions in cisgender boys. Thus, cortical morphometry (mainly SA) was related to sex assigned at birth, but not experienced gender. Effects of experienced gender were found as similarities in correlation patterns in GD AFAB and cisgender boys in age and sexual orientation (mainly T1), indicating the need to consider developmental trajectories and sexual orientation in brain studies of GD.

Biological sex classification with structural MRI data shows increased misclassification in transgender women

Transgender individuals (TIs) show brain-structural alterations that differ from their biological sex as well as their perceived gender. To substantiate evidence that the brain structure of TIs differs from male and female, we use a combined multivariate and univariate approach. Gray matter segments resulting from voxel-based morphometry preprocessing of N = 1753 cisgender (CG) healthy participants were used to train (N = 1402) and validate (20% holdout N = 351) a support-vector machine classifying the biological sex. As a second validation, we classified N = 1104 patients with depression. A third validation was performed using the matched CG sample of the transgender women (TW) application sample. Subsequently, the classifier was applied to N = 26 TW. Finally, we compared brain volumes of CG-men, women, and TW-pre/post treatment cross-sex hormone treatment (CHT) in a univariate analysis controlling for sexual orientation, age, and total brain volume. The application of our biological sex classifier to the transgender sample resulted in a significantly lower true positive rate (TPR-male = 56.0%). The TPR did not differ between CG-individuals with (TPR-male = 86.9%) and without depression (TPR-male = 88.5%). The univariate analysis of the transgender application-sample revealed that TW-pre/post treatment show brain-structural differences from CG-women and CG-men in the putamen and insula, as well as the whole-brain analysis. Our results support the hypothesis that brain structure in TW differs from brain structure of their biological sex (male) as well as their perceived gender (female). This finding substantiates evidence that TIs show specific brain-structural alterations leading to a different pattern of brain structure than CG-individuals.

Analysis of Four Polymorphisms Located at the Promoter of the Estrogen Receptor Alpha ESR1 Gene in a Population With Gender Incongruence

INTRODUCTION

Gender incongruence defines a state in which individuals feel discrepancy between the sex assigned at birth and their gender. Some of these people make a social transition from male to female (trans women) or from female to male (trans men). By contrast, the word cisgender describes a person whose gender identity is consistent with their sex assigned at birth.

AIM

To analyze the implication of the estrogen receptor α gene (ESR1) in the genetic basis of gender incongruence.

MAIN OUTCOME MEASURES

Polymorphisms rs9478245, rs3138774, rs2234693, rs9340799.

METHOD

We carried out the analysis of 4 polymorphisms located at the promoter of the ESR1 gene (C1 = rs9478245, C2 = rs3138774, C3 = rs2234693, and C4 = rs9340799) in a population of 273 trans women, 226 trans men, and 537 cis gender controls. For SNP polymorphisms, the allele and genotype frequencies were analyzed by χ² test. The strength of the SNP associations with gender incongruence was measured by binary logistic regression. For the STR polymorphism, the mean number of repeats were analyzed by the Mann-Whitney U test. Measurement of linkage disequilibrium and haplotype frequencies were also performed.

RESULTS

The C2 median repeats were shorter in the trans men population. Genotypes S/S and S/L for the C2 polymorphism were overrepresented in the trans men group (P = .012 and P = .003 respectively). We also found overtransmission of the A/A genotype (C4) in the trans men population (P = .017), while the A/G genotype (C4) was subrepresented (P = .009]. The analyzed polymorphisms were in linkage disequilibrium. In the trans men population, the T(C1)-L(C2)-C(C3)-A(C4) haplotype was overrepresented (P = .019) while the T(C1)-L(C2)-C(C3)-G(C4) was subrepresented (P = .005).

CONCLUSION

The ESR1 is associated with gender incongruence in the trans men population. Fernández R, Delgado-Zayas E,RamírezK, et al. Analysis of Four Polymorphisms Located at the Promoter of the Estrogen Receptor Alpha ESR1 Gene in a Population With Gender Incongruence. Sex Med 2020;8:490-500.

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.

Sex differences and brain development during puberty and adolescence

Sex differences in behavior, and whether these behavioral differences are related to sex differences in brain development, has been a longstanding topic of debate. Presumably, sex differences can provide critically important leads for explaining the etiology of various illnesses that show (i) large sex differences in prevalence and (ii) have an origin before or during adolescence. The general aim of this chapter is to provide an overview of scientific studies on sex differences in normative brain and behavioral development across puberty and adolescence, including the (sex) hormone-driven transition phase of puberty. Moreover, we describe the literature on brain and behavioral development in gender dysphoria, a severe and persistent incongruence between the self-identified gender and the assigned sex at birth. From the literature it becomes clear there is evidence for a specific link between pubertal maturation and developmental changes in arousal, motivation, and emotion. However, this link is rather similar between boys and girls. Moreover, although there is substantial evidence for sex differences in mean brain structure, these have not always been linked to sex differences in behavior, cognition, or psychopathology. Furthermore, there is little evidence for sex differences in brain development and thus, studies so far have been unable to explain sex differences in cognition. Suggestions for future research and methodologic considerations are provided.

Neuroendocrine pathways underlying risk and resilience to PTSD in women

Women are twice as likely than men to suffer from posttraumatic stress disorder (PTSD). While women have increased exposure to traumatic events of many types and have greater prevalence of comorbid psychiatric disorders compared to men, these differences do not account for the overall sex difference in the prevalence of PTSD. The current review summarizes significant findings that implicate the role of estradiol, progesterone, and allopregnanolone in female risk for PTSD symptoms and dysregulation of fear psychophysiology that is cardinal to PTSD. We also discuss how these steroid hormones influence the stress axis and neural substrates critical for the regulation of fear responses. Understanding the role of ovarian steroid hormones in risk and resilience for trauma-related adverse mental health outcomes across the lifespan in women has important translational, clinical, and intergenerational implications for mitigating the consequences of trauma exposure.

Effects of Estradiol Therapy on Resting-State Functional Connectivity of Transgender Women After Gender-Affirming Related Gonadectomy

An extreme incongruence between sex and gender identity leads individuals with gender dysphoria (GD) to seek cross-sex hormone therapy (CSHT), and gender-affirming surgery (GAS). Although few studies have investigated the effects of CSHT on the brain prior to GAS, no studies in the extant literature have evaluated its impact during hypogonadism in post-GAS individuals. Here, we aimed to evaluate the effects of estradiol on resting-state functional connectivity (rs-FC) of the sensorimotor cortex (SMC) and basal ganglia following surgical hypogonadism. Eighteen post-GAS (male-to-female) participants underwent functional magnetic resonance imaging (fMRI) and neuropsychiatric and hormonal assessment at two time points (t1, hormonal washout; t2, CSHT reintroduction). Based on the literature, the thalamus was selected as a seed, while the SMC and the dorsolateral striatum were targets for seed-based functional connectivity (sbFC). A second sbFC investigation consisted of a whole-brain voxel exploratory analysis again using the thalamus as a seed. A final complementary data-driven approach using multivoxel pattern analysis (MVPA) was conducted to identify a potential seed for further sbFC analyses. An increase in the rs-FC between the left thalamus and the left SCM/putamen followed CSHT. MVPA identified a cluster within the subcallosal cortex (SubCalC) representing the highest variation in peak activation between time points. Setting the SubCalC as a seed, whole-brain analysis showed a decoupling between the SubCalC and the medial frontal cortex during CSHT. These results indicate that CSHT with estradiol post-GAS, modulates rs-FC in regions engaged in cognitive, emotional, and sensorimotor processes.

Gender-Affirming Hormone Use in Transgender Individuals: Impact on Behavioral Health and Cognition

PURPOSE OF REVIEW

With increasing numbers of transgender and gender non-binary individuals presenting for care, knowing how to elucidate the mental health and cognitive outcomes of gender-affirming hormone therapy (GAHT) is necessary. This article reviews the present literature covering GAHT effects on mood, behavioral health, and cognition in these individuals and offers research priorities to address knowledge gaps.

RECENT FINDINGS

Although there are some conflicting data, GAHT overwhelmingly seems to have positive psychological effects in both adolescents and adults. Research tends to support that GAHT reduces symptoms of anxiety and depression, lowers perceived and social distress, and improves quality of life and self-esteem in both male-to-female and female-to-male transgender individuals. Clinically, prescribing GAHT can help with gender dysphoria-related mental distress. Thus, timely hormonal intervention represents a crucial tool for improving behavioral wellness in transgender individuals, though effects on cognitive processes fundamental for daily living are unknown. Future research should prioritize better understanding of how GAHT may affect executive functioning.