After 30 years as one of England's top pediatricians, Dr. Hilary Cass ... took on a project that would throw her into an international fire: reviewing England's treatment guidelines for the rapidly rising number of children with gender distress, known as dysphoria. Staff members who said they felt pressure to approve children for puberty-blocking drugs had filed whistle-blower complaints. Over the next four years, Dr. Cass commissioned systematic reviews of scientific studies on youth gender treatments and international guidelines of care. She also met with young patients and their families, transgender adults, people who had detransitioned, advocacy groups and clinicians. Her final report, published last month, concluded that the evidence supporting the use of puberty-blocking drugs and other hormonal medications in adolescents was "remarkably weak." On her recommendation, the N.H.S. will no longer prescribe puberty blockers outside of clinical trials. Dr. Cass also recommended that testosterone and estrogen, which allow young people to develop the physical characteristics of the opposite sex, be prescribed with "extreme caution." "We have to stop just seeing these young people through the lens of their gender and see them as whole people, and address the much broader range of challenges that they have ... I've spoken to young adults where it was the wrong decision, where they have regret, where they've detransitioned. The critical issue is trying to work out how we can best predict who's going to thrive and who's not going to do well," [said Dr. Cass]. "Medicine should never be politically driven. It should be driven by evidence and ethics and shared decision-making with patients and listening to patients' voices. Once it becomes politicized, then that's seriously concerning, as you know well from the abortion situation in the United States."