Differences Between Trans-Men and Trans-Women in Sexual Orientation and Clinical Characteristics in Japan

Research on transgender individuals in Japan remains limited, particularly regarding within-group diversity, such as differences in gender identity, sexual orientation, and clinical characteristics. This study aims to explore the diversity of sexual orientation among transgender individuals in Japan, and its associations with gender identity, age, hormone therapy, and key psychological outcomes. A total of 199 participants (146 trans-men and 53 trans-women) were recruited from a psychiatric clinic and completed a questionnaire including measures of gender dysphoria (UGDS), health-related quality of life (SF-36v2), autistic traits (AQ), and the gender(s) to whom they felt sexual attraction. Sexual orientation was classified into five categories based on gender identity and sexual attraction. Results showed that heterosexual orientation was more prevalent among trans-men and younger individuals, while hormone therapy was not associated with sexual orientation. Among trans-men, hormone therapy was significantly associated with reduced gender dysphoria, particularly among those identifying as non-heterosexual. Trans-men reported higher SF-36v2 scores than trans-women across most subscales, while no differences based on sexual orientation. No differences in AQ scores were found based on gender identity or sexual orientation. These findings highlight the importance of considering sexual orientation and other individual differences in transgender clinical support in Japan.