The National Institutes of Health has awarded $5.7M for a five-year, multicenter study, which will be the first in the U.S. to evaluate the long-term outcomes of medical treatment for transgender youth. This study will provide essential, evidence-based information on the physiological and psychosocial impact, as well as safety, of hormone blockers and cross-sex hormones use in this population.

"There is a remarkable increase in transgender youth seeking medical services all across the country," said Stephen Rosenthal, MD, co-investigator on the study and medical director of the Child and Adolescent Gender Center (CAGC) at UCSF Benioff Children's Hospital San Francisco. "Yet, there is a real lack of long-term data to effectively and safely guide the clinical care of these youth. This study should address that need."

The multicenter study will be located at four academic medical centers with dedicated transgender youth clinics. The co-investigators and their institutions include:

- Johanna Olson, MD, Children's Hospital Los Angeles and the Keck School of Medicine of the University of Southern California

- Stephen Rosenthal, MD, UCSF Benioff Children's Hospital San Francisco

- Robert Garofalo, MD, MPH, Ann & Robert H. Lurie Children's Hospital of Chicago and Northwestern University Feinberg School of Medicine

- Norman Spack, MD, Boston Children's Hospital and Harvard Medical School.

"We are pleased to see transgender medicine taking its place on the national health agenda," said Olson, medical director of the Center for Transyouth Health at Children's Hospital Los Angeles. "Results of this study will help physicians across the country provide the best and safest possible care for transgender youth."

The study - which will begin enrollment in fall 2015—will include 280 transgender youth with gender dysphoria—those who are persistently distressed by the incongruity between their gender of identity and the gender they were assigned at birth. Participants will be those who seek medical intervention to align their physical bodies with their gender identity and alleviate gender dysphoria and its associated negative effects, including anxiety, depression and substance abuse.

The study will include youth from two age groups: younger children in early puberty, who will receive hormone blockers, called GnRH agonists, used to suspend the process of puberty - preventing the development of undesired secondary sex characteristics; and older adolescents, who will begin use of masculinizing or feminizing cross-sex hormones that allow them to go through the 'right' puberty - consistent with their gender of identification.

For the cohort in the earliest stages of puberty, the study will evaluate the impact of treatment on mental health, psychological well-being, physiologic parameters and bone health, and will document the safety of hormone blockers. In the older group, the study will document the safety of administering cross-sex hormones for phenotypic gender transition, as well as evaluate its impact on mental health, psychological well-being, and certain metabolic/physiological parameters.