Background: Over the last 50 years, several studies have provided estimates of the prevalence of transsexualism. The variation in reported prevalence is considerable and may be explained by factors such as the methodology and diagnostic classification used and the year and country in which the studies took place. Taking these into consideration, this study aimed to critically and systematically review the available literature measuring the prevalence of transsexualism as well as performing a meta-analysis using the available data.Methods: Databases were systematically searched and 1473 possible studies were identified. After initial scrutiny of the article titles and removal of those not relevant, 250 studies were selected for further appraisal. Of these, 211 were excluded after reading the abstracts and a further 18 after reading the full article. This resulted in 21 studies on which to perform a systematic review, with only 12 having sufficient data for meta-analysis. The primary data of the epidemiological studies were extracted as raw numbers. An aggregate effect size, weighted by sample size, was computed to provide an overall effect size across the studies. Risk ratios and 95% confidence intervals (CIs) were calculated. The relative weighted contribution of each study was also assessed.Results: The overall meta-analytical prevalence for transsexualism was 4.6 in 100,000 individuals; 6.8 for trans women and 2.6 for trans men. Time analysis found an increase in reported prevalence over the last 50 years.Conclusions: The overall prevalence of transsexualism reported in the literature is increasing. However, it is still very low and is mainly based on individuals attending clinical services and so does not provide an overall picture of prevalence in the general population. However, this study should be considered as a starting point and the field would benefit from more rigorous epidemiological studies acknowledging current changes in the classification system and including different locations worldwide.

Literature has described high levels of mental health problems among trans people, such as depression, resulting in increased levels of non-suicidal self-injury (NSSI) behaviour and suicidality (suicidal thoughts, suicide attempts and suicide rates). With the aim of systematically reviewing the available literature in this field, this study identifies 31 papers that explore the rates of NSSI and suicidality in trans people. From reviewing the literature, it was revealed that trans people have a higher prevalence of NSSI and suicidality compared to the cisgender (non-trans) population. There appear to be some gender differences within these rates, with trans men at a greater risk for NSSI behaviour. Prevalence rates differ depending on the different stages of transition, but they are still overall greater than the cisgender population. The study concludes that trans individuals are at a greater risk of NSSI behaviour and suicidality than the cisgender population, and discusses risk factors and the need to develop effective preventative interventions.

Eating disorders in dancers are thought to be common, but the exact rates remain to be clarified. The aim of this study is to systematically compile and analyse the rates of eating disorders in dancers. A literature search, appraisal and meta‐analysis were conducted. Thirty‐three relevant studies were published between 1966 and 2013 with sufficient data for extraction. Primary data were extracted as raw numbers or confidence intervals. Risk ratios and 95% confidence intervals were calculated for controlled studies. The overall prevalence of eating disorders was 12.0% (16.4% for ballet dancers), 2.0% (4% for ballet dancers) for anorexia, 4.4% (2% for ballet dancers) for bulimia and 9.5% (14.9% for ballet dancers) for eating disorders not otherwise specified (EDNOS). The dancer group had higher mean scores on the EAT‐26 and the Eating Disorder Inventory subscales. Dancers, in general, had a higher risk of suffering from eating disorders in general, anorexia nervosa and EDNOS, but no higher risk of suffering from bulimia nervosa. The study concluded that as dancers had a three times higher risk of suffering from eating disorders, particularly anorexia nervosa and EDNOS, specifically designed services for this population should be considered. Copyright © 2013 John Wiley & Sons, Ltd and Eating Disorders Association.

Objectives We systemically reviewed the literature to assess how long-term testosterone suppressing gender-affirming hormone therapy influenced lean body mass (LBM), muscular area, muscular strength and haemoglobin (Hgb)/haematocrit (HCT). Design Systematic review. Data sources Four databases (BioMed Central, PubMed, Scopus and Web of Science) were searched in April 2020 for papers from 1999 to 2020. Eligibility criteria for selecting studies Eligible studies were those that measured at least one of the variables of interest, included transwomen and were written in English. Results Twenty-four studies were identified and reviewed. Transwomen experienced significant decreases in all parameters measured, with different time courses noted. After 4 months of hormone therapy, transwomen have Hgb/HCT levels equivalent to those of cisgender women. After 12 months of hormone therapy, significant decreases in measures of strength, LBM and muscle area are observed. The effects of longer duration therapy (36 months) in eliciting further decrements in these measures are unclear due to paucity of data. Notwithstanding, values for strength, LBM and muscle area in transwomen remain above those of cisgender women, even after 36 months of hormone therapy. Conclusion In transwomen, hormone therapy rapidly reduces Hgb to levels seen in cisgender women. In contrast, hormone therapy decreases strength, LBM and muscle area, yet values remain above that observed in cisgender women, even after 36 months. These findings suggest that strength may be well preserved in transwomen during the first 3 years of hormone therapy.

High levels of body dissatisfaction have already been reported in the trans population; however, the root of this dissatisfaction, and its association with eating disordered behaviours, has not been studied in‐depth. This study aims to assess eating disorder risk by comparing 200 trans people, 200 people with eating disorders and 200 control participants' scores on three subscales of the Eating Disorders Inventory‐2 (EDI‐2) and to further explore dissatisfaction in the trans participants using the Hamburg Body Drawing Scale (HBDS). The results showed that overall participants with eating disorders scored higher than trans or control groups on all EDI‐2 measures, but that trans individuals had greater body dissatisfaction than control participants and, importantly, trans males had comparable body dissatisfaction scores to eating disordered males. Drive for thinness was greater in females (cis and trans) compared with males. In relation to HBDS body dissatisfaction, both trans males and trans females reported greatest dissatisfaction not only for gender‐identifying body parts but also for body shape and weight. Overall, trans males may be at particular risk for eating disordered psychopathology and other body image‐related behaviours. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.

Introduction: There is a paucity of systematic research in the area of non-suicidal self-injury (NSSI) in trans people.Aim: The aim of this study was to investigate the prevalence of NSSI in trans people and the associations with intra- and interpersonal problems.Methods: Participants were 155 untreated individuals with a diagnosis of transsexualism (according to International Classification of Disease-10 criteria) attending a national gender identity clinic.Main Outcome Measures: All participants completed the Self-Injury Questionnaire, the Symptom Checklist-90-Revised, the Rosenberg Self-Esteem Scale, the Hamburg Body Drawing Scale, the Experiences of Transphobia Scale, the Inventory of Interpersonal Problems-32, and the Multidimensional Scale of Perceived Social Support.Results: The sample consisted of 66.5% trans women and 33.5% trans men and 36.8% of them had a history of engaging in NSSI. The prevalence of NSSI was significantly higher in trans men (57.7%) compared with trans women (26.2%). Trans individuals with NSSI reported more psychological and interpersonal problems and perceived less social support compared with trans individuals without NSSI. Moreover, the probability of having experienced physical harassment related to being trans was highest in trans women with NSSI (compared with those without NSSI). The study found that with respect to psychological symptoms, trans women reported significantly more intrapersonal and interpersonal symptoms compared with trans men. Finally, the results of the regression analysis showed that the probability of engaging in NSSI by trans individuals was significantly positively related to a younger age, being trans male, and reporting more psychological symptoms.Conclusions: The high levels of NSSI behavior and its association with interpersonal and interpersonal difficulties and lack of social support need to be taken into consideration when assessing trans individuals. The effect of cross-sex hormones and sex reassignment surgery on psychological functioning, including NSSI behavior, as part of the transitional journey of trans individuals should be explored in future studies.