There are modest effects on depression but not anxiety. Gender-affirming hormone therapy (GAHT) is associated with modest improvements in standardized scores for quality of life (QOL) and depression in adult male-to-female and female-to-male transgender people and modest improvements in depression scores in transgender adolescents, but the effect on anxiety is uncertain (strength of recommendation [SOR]: B, based on a preponderance of low-quality prospective cohort studies with inconsistent results). GAHT is associated with reduced gender dysphoria and decreased suicidality (SOR: B, based on a prospective cohort study). However, there is insufficient evidence to determine any effect on suicide completion. No studies associated GAHT with worsened QOL, depression, or anxiety scores.