Many trans individuals seek clinial services as they want and decide to have cross-sex hormone treatment and surgery in hopes of alleviating their gender dysphoria and gender incongruence. Moreover there are many trans individuals who may have socially transitioned with or without various treatments through private means. Special issue dedicated to the 24th biennial WPATH Symposium in Amsterdam, containing twelve papers highlighting the broad spectrum of clinical and research topics within the interdisciplinary field of transgender healthcare. The focus in on mental health across the life span.