Consequences of cross-gender hormonal therapy in transsexuals
Sex hormones are not only involved in the formation of reproductive organs, but also induce sexually-dimorphic brain development and organization. Transsexualism is the condition in which a person with apparently normal somatic sexual differentiation of one sex is convinced that he or she is actually a member of the opposite sex. This sense is so pronounced and persistent that transsexuals seek treatment to, as far as medically possible, physically change their bodies from male into female or vice versa. Prior to surgical sex reassignment, transsexuals receive treatment with cross-sex hormones.
It is well established in mammals that differences in male and female brain structures can be reversed by sex hormones, even in adulthood. There is some indication that this can also be observed in transsexual subjects treated with gonadal hormones. Since there is no known fundamental difference in sensitivity to the biological action of sex steroids on the basis of genetic configurations or gonadal status, the influence of cross-sex hormones can be studied relatively independent of the original endocrine status as male or female.
Cross-sex hormone administration to transsexuals therefore provides a unique possibility to study the effects of sex steroids on the brain. We are currently undertaking a cross-sectional study of neuropsychiatric and sleep-related aspects of cross-gender therapy as well as etiological aspects in transsexual patients. In the future we plan to focus on longitudinal research designs and to seek out and include genetic information.
Research groups involved:
RG Thomas Wetter: Stephany Fulda
RG Günter Stalla: Caroline Sievers, Maria Angeles Bazarra-Castro, Christina Dimopoulou