PURPOSE: Limited data exist about the emotional health of transgender youth, either before or after initiation of gender-affirming hormone (GAH). The objectives were: (1) Investigate and verify the factor structure of the National Institutes of Health Toolbox Emotional Battery (NIHTB-EB) among trans and non-binary (TNB) youth
(2) Examine changes in emotional health over 24 months of GAH treatment
and (3) Examine the extent to which changes in emotional health were associated with improved appearance congruence (AC). METHODS: Study respondents were from Trans Youth Care - United States (TYCUS) study, an observational, prospective, longitudinal study of adolescents initiating GAH enrolled between 2016 and 2019. Data were obtained at baseline, 6, 12, 18 and 24 months following initiation of GAHtreatment. Participants were receiving services at one of the 4 study sites. Eligible participants were those with gender dysphoria, aged 12-20 years, naïve to GAH, and initiating GAH for the purpose of phenotypic gender transition. RESULTS: 315 youth aged 12-20 years (M = 16.1, SD = 1.87) were predominantly White (58.7%) and transmasculine (65%). Factor analysis of the NIHTB-EB measures yielded 4 emotional health dimensions, consistent with prior studies of other cohorts. Over the observation period, participants demonstrated significant improvements in AC, psychological well-being, social satisfaction and self-efficacy and significant reductions in negative affect and negative social perception. Significant associations between AC and different indicators of emotional functioning were observed at baseline and over time. DISCUSSION: Emotional functioning after 24 months of GAH treatment significantly improved and was associated with an improvement in AC.