The Effect of Gender-Affirming Hormones on Gender Dysphoria, Quality of Life, and Psychological Functioning in Transgender Individuals: A Systematic Review.

Gender-affirming hormone therapy (GAHT) is an essential part of gender affirmation for many transgender (including people with binary and nonbinary identities) individuals and although controlled studies are unethical, there remains limited evidence on the impact of GAHT on gender dysphoria, quality of life (QoL), and psychological functioning. Some clinicians and policy makers use the lack of evidence to argue against providing gender-affirming care. The aim of this review is to systematically and critically assess the available literature on the influence of GAHT on improving gender- and body-related dysphoria, psychological well-being, and QoL. Using Preferred Reporting Items for Systematic Review and Meta-analysis guidelines, we searched Ovid MEDLINE^®, Embase^®, and Ovid PsycINFO^® from inception to March 6, 2019 to assess the influence of GAHT on (1) gender dysphoria, (2) body uneasiness, (3) body satisfaction, (4) psychological well-being, (5) QoL, (6) interpersonal and global functioning, and (7) self-esteem. Our search strategy found no randomized controlled trials. Ten longitudinal cohort studies, 25 cross-sectional studies, and 3 articles reporting both cross-sectional and longitudinal data were identified. While results are mixed, the majority of studies demonstrate that GAHT reduces gender dysphoria, body dissatisfaction, and uneasiness, subsequently improving psychological well-being and QoL in transgender individuals. However, all current researches are of low to moderate quality comprising longitudinal cohort studies and cross-sectional studies, making it difficult to draw clear conclusions and do not reflect external social factors unaffected by GAHT, which significantly impact on dysphoria, well-being, and QoL.