{Reference Type}: Journal Article {Title}: Mental Health Diagnoses and Suicidality Among Transgender Youth in Hospital Settings. {Author}: Nunes-Moreno M;Furniss A;Cortez S;Davis SM;Dowshen N;Kazak AE;Nahata L;Pyle L;Reirden DH;Schwartz B;Sequeira GM;Nokoff NJ; {Journal}: LGBT Health {Volume}: 0 {Issue}: 0 {Year}: 2024 Jul 17 {Factor}: 5.15 {DOI}: 10.1089/lgbt.2023.0394 {Abstract}: Purpose: The purpose of this analysis is to: 1) describe the most common mental health diagnoses in the emergency department (ED) and inpatient hospital settings among transgender and gender diverse (TGD) youth vs. matched controls and 2) evaluate if a gender-affirming hormone therapy (GAHT) or gonadotropin-releasing hormone agonist (GnRHa) prescription decreased the risk of suicidality within these settings. Methods: Using the PEDSnet dataset (years 2009-2019), TGD youth aged 8-18 (n = 3414, with a median age at last visit of 16.2 [14.4, 17.7] years, were propensity-score matched to controls (n = 13,628, age 16.6 [14.2, 18.3] years). Relative risks of the most common mental health diagnoses within ED and inpatient settings were calculated for TGD youth compared with controls. Recurrent time-to-event analysis was used to examine whether GAHT or GnRHa attenuated the risk of suicidality among subsamples of TGD youth. Results: TGD youth had a higher relative risk (95% confidence interval [CI]) of mental health diagnoses and suicidality in the ED (5.46 [4.71-6.33]) and inpatient settings (6.61 [5.28-8.28]) than matched controls. TGD youth prescribed GAHT had a 43.6% lower risk of suicidality (hazard ratio [HR] = 0.564 [95% CI 0.36-0.89]) compared with those never prescribed GAHT during our study period or before GAHT initiation. TGD youth who were prescribed GnRHa therapy had a nonstatistically significant reduction in ED or inpatient suicidality diagnoses compared with those never prescribed GnRHa (HR = 0.79 [0.47-1.31]). Conclusion: Although risk of mental health diagnoses and suicidality in ED and inpatient settings was high among TGD youth, a GAHT prescription was associated with a significant reduction in suicidality risk.