Androgen treatment effects on memory in female-to-male transsexuals

It has been hypothesized that cognitive and memory-related brain function in transsexuals during cross-sex hormonal treatment might be activated towards that of the subjective gender. However, research on this topic has produced inconsistent results, and to the best of our knowledge no studies have investigated memory changes in androgen-treated female-to-male (FM) transsexuals.

A total of 33 FM transsexuals underwent neuropsychological testing in order to examine the effects of androgen on memory. We used a longitudinal design in which 14 FM transsexuals were tested twice, before and after receiving 6 months of testosterone treatment. In addition, a cross-sectional design was used to compare 10 individuals off treatment versus 9 individuals on testosterone treatment for at least 6 months.

Participants tested before and after 6 months of androgen treatment improved significantly their performance on a visual memory task (visual paired associates, immediate recall, WMS-R). The cross-sectional design confirmed that patients on androgen treatment for at least 6 months performed better than subjects off treatment on the same task and also on another visual memory task (Rey-Osterrieth complex figure test, ROCF; copy and delayed recall). No differences were found in any verbal memory test for either design.

The results indicate that androgen has an influence on visual memory, but not on verbal memory. Therefore, for FM transsexuals the data support an activating effect for androgens on visual memory, a domain that generally tends to favour males.