There’s been a lot of hue and cry recently about sex change operations and liberating one’s ‘inner-self’. While the hormonal treatments given during sex reassignment operations are commonly known to affect an adult’s secondary sexual characteristics, a new study reveals that these hormonal administrations also modify brain chemistry.

Sex Alteration: The Basic Findings

Led by senior authors Dr. Siegfried Kasper and Dr. Rupert Lanzenberger, researchers at the Medical University of Vienna demonstrate how the administration of testosterone (male reproductive hormone) in female-to-male transsexuals increases the levels of SERT in their brains. SERT is a protein that transports the neurotransmitter serotonin into nerve cells.

In comparison, male-to-female transsexuals are administered a testosterone blocker along with the female hormone estrogen. This in turn decreases the levels of SERT in the brain.

Understanding Alterations Within The Brain: The Role Of SERT

SERT is integral in treating anxiety and mood disorders. Various antidepressants function by blocking the activity of SERT which in turn inhibits the uptake of serotonin. Furthermore, certain genetic studies also suggest that elevated amounts of serotonin transporter could increase resilience towards stress and lower the risk of developing stress and mood disorders.

Since women are twice as likely to develop depression as compared to men, the alterations in the levels of SERT due to hormonal treatments are consistent with an increased likelihood of anxiety and mood disorders in women relative to men.

“These results help explain why testosterone improves symptoms in certain types of depression. Also, the study increases our understanding about the function of sex hormones in establishing sex differences among mood disorders”, stated Lanzenberger.

Devising A Conclusion

Overall, the study concludes that during female-to-male sex change operations, the brain chemistry is altered so as to reduce the risk of developing anxiety and mood disorders, whereas the opposite happens during a male-to-female switch.

“This study is the first to highlight modifications in brain chemistry due to hormonal treatments administered during sex change processes”, said Dr. John Krystal, Editor of Biological Psychiatry. “It provides novel insights into how hormonal differences between males and females influence mood, and the likelihood of mood disorders”.

The research was published in the latest issue of Biological Psychiatry .