Efficacy of hormonal and mental treatments with MMPI in FtM individuals: cross-sectional and longitudinal studies

Background: Cross-sex hormone treatment (CSHT) is an important option for gender dysphoria (GD) individuals to improve the quality of life. However, in Japan, sex reassignment surgery (SRS) and CSHT for GD had been discontinued until 1998 (over 30 years). After resumption, the number of GD individuals wishing treatment rapidly increased. On the other hand, the number of medical institutions available for evaluation was limited. For this reason, hormonal treatment has been administered to GD individuals requiring the prompt start of CSHT in the absence of mental health assessment by specialists. In this study, we examined the efficacy of CSHT and psychotherapy. Methods: The participants were 155 female-to-male (FtM) individuals who consulted our gender identity clinic, and were definitively diagnosed. A cross-sectional study was conducted by dividing them into two groups: groups with and without CSHT on the initial consultation (Group CSHT: n = 53, Group no-CSHT: n = 102). In all participants, Minnesota Multiphasic Personality Inventory (MMPI) and blood hormone tests were performed on the initial consultation. In addition, CSHT was combined with psychotherapy for a specific period in Group no-CSHT, and FtM individuals in whom an additional MMPI test could be conducted (Group combined treatment (CT), n = 14) were enrolled in a longitudinal study. Results: In the cross-sectional study, there was no significant difference on the MMPI test. In the longitudinal study, there were improvements in the clinical scales other than the Mf scale on the MMPI test. In Group CT, the D, Sc, and Si scale scores on the initial consultation were significantly higher than in Group CSHT. However, there was no clinical scale with a significantly higher value after the start of treatment. The Pd scale score was significantly lower. Conclusions: CSHT improved mental health. Psychotherapy-combined CSHT may further improve it.