Historically, medical interventions to achieve the appearance of the desired sex were reserved primarily for adults with long histories of dysphoria. Medical interventions were preceded by a prolonged engagement with the patient, including thorough psychological assessments. While the population-level data on the benefits of adult gender transitions undertaken in prior decades remain mixed, with evidence of persistent mental health struggles and sharply elevated mortality and morbidity, a number of individuals who underwent gender transition following rigorous assessments have reported being very satisfied with their decision to transition, do not regret it, and live happy and productive lives.
However, around 2010's, there was a marked change in the approach to the management of gender dysphoria. A number of countries in Western Europe, North America, and Australia, began to promote the "gender-affirmative" model of care for youth. Under this model of care, young people presenting with gender dysphoria or asserting a transgender identity are affirmed in their desire to undergo gender transition, and are provided with hormonal and surgical interventions. While mental health professionals are often involved, their role is typically limited to preparing the young person for gender transition, regardless of any co-occurring mental health challenges or whether there was a relatively recent history of transgender identification. As such, the provision of medical intervention now happens with a much-reduced psychological assessment.
(Source: "Society for Evidence-Based Gender Medicine")