Practitioner's CornerThe Impact of Gender-affirming Hormone Therapy on Anatomic Structures of the Brain Among Transgender IndividualsO’Leary, Kerry B. MD, MPH; Garcia-Altieri, Mauro A. MD Author Information O’LEARY and GARCIA-ALTIERI: Menninger Department of Psychiatry & Behavioral Sciences, Baylor College of Medicine, Houston, TX The authors declare no conflicts of interest. Please send correspondence to: Kerry B. O’Leary, MD, MPH, Menninger Department of Psychiatry & Behavioral Sciences, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030 (e-mail: kerry.o’[email protected]). Journal of Psychiatric Practice 28(4):p 328-334, July 2022. | DOI: 10.1097/PRA.0000000000000633 Buy Metrics Abstract Despite the growing numbers of individuals who identify as transgender, this population continues to face worse mental health outcomes compared with the general population. Transgender individuals attempt suicide at a rate that is almost 9 times that of the general population. Few studies have reported on the positive effect of gender-affirming hormone therapy on mental health outcomes in transgender individuals. It is likely that this effect is due in part to the physiological responses that occur as a result of hormone therapy that mitigate incongruencies between one’s gender identity and assigned sex. To our knowledge, only limited studies have shown a connection between gender-affirming hormone therapy, its effect on the brain’s structure, and long-term effects that this may have on mental health outcomes. The authors propose that, in addition to the physiological responses that occur as a direct result of hormone therapy and the validation that results from receiving gender-affirming medical care, mental health outcomes in transgender individuals may also improve due to the role that hormone therapy plays in altering the brain’s structure, possibly shaping the brain to become more like that of the gender with which an individual identifies. In this article, the authors review the current literature on the effects that gender-affirming hormone therapy has on mental health outcomes and anatomic structures of the brain in transgender individuals. Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.