Summary

The Cass Review was set up after referrals to England's child gender service rose sharply and the patients changed to mostly teenage girls, many with autism or mental health problems. Its final report found that care had rested on 'remarkably weak' evidence. Reviews by the University of York could draw no conclusions on how puberty blockers (drugs that pause puberty) affect gender distress or mental health, and found only limited evidence for hormones. Cass recommended whole-person assessment, standard psychological support, blockers only in a research trial, 'extreme caution' with hormones before 18, national review of every medical case, and regional services. It is the most thorough review of its kind, and later reviews agree the evidence is weak. Its methods are disputed, critics and defenders both have stakes, and some advice rests on judgement rather than data.

Key findings

• 该报告由NHS英格兰于2020年设立，2024年4月10日发布，共388页，为英格兰儿童和青少年性别服务提出32项建议。
• 约克大学对青春期阻断剂的综述考察了50项研究（1项高质量，25项中等，24项低质量）。综述称，无法就其对性别痛苦、心理健康或大脑发育的影响得出结论，并且骨骼健康和身高可能受到损害。
• 约克大学对跨性别激素的综述考察了53项研究（1项高质量，33项中等，19项低质量）。它发现有中等质量的证据表明治疗期间心理健康可能改善，但对其他影响无法得出结论。
• 评估建议进行全人评估，包括自闭症及类似状况的筛查和心理健康评估，并使用标准的、经过验证的谈话治疗和药物来应对痛苦和其他状况。
• 青春期阻断剂应仅在研究中给予（NHS英格兰已推进一项试验）。16岁起使用激素需“极度谨慎”，并有明确理由说明为何不等到18岁，而且每一例医学治疗的个案都应提交国家专家小组。
• 评估发现，包括WPATH（世界跨性别健康专业协会）在内的指南并非经过严谨制定。七家NHS成人性别诊所中有六家拒绝为一项长期结果研究共享数据，评估认为应要求它们参与。
• 为幼儿进行社会性过渡（新名字、衣服或代词）而做决定的家庭，应尽早看有经验的临床医生，并且在任何医学治疗之前，所有年轻人都应获得生育咨询以及冷冻卵子或精子的机会。
• 该报告受到耶鲁大学诚信项目（McNamara及同事，2024年）和一篇同行评议论文（Noone及同事，2025年）的批评。《儿童疾病档案》（Cheung及同事，2025年）和《性与婚姻治疗杂志》（McDeavitt及同事，2025年）则为其辩护。

Abstract

1. The aim of this Review is to make recommendations that ensure that children and young people who are questioning their gender identity or experiencing gender dysphoria receive a high standard of care. Care that meets their needs, is safe, holistic and effective. At its heart are vulnerable children and young people and an NHS service unable to cope with the demand. 2. Yet from the start, the Review stepped into an arena where there were strong and widely divergent opinions unsupported by adequate evidence. The surrounding noise and increasingly toxic, ideological and polarised public debate has made the work of the Review significantly harder and does nothing to serve the children and young people who may already be subject to significant minority stress. 3. Within this context the Review set out to understand the reasons for the growth in referrals and the changing epidemiology, and to identify the clinical approach and service model that would best serve this population. 4. There are conflicting views about the clinical approach, with expectation at times being far from usual clinical practice. This has made some clinicians fearful of working with gender-questioning young people, despite their presentation being similar to many children and young people presenting to other NHS services. 5. Although some think the clinical approach should be based on a social justice model, the NHS works in an evidence-based way. Whilst navigating a way through the surrounding ‘culture war’, the Review has been acutely and increasingly aware of the need for evidence to support its thinking and ultimately the final recommendations made in this report. 6. When the Review started, the evidence base, particularly in relation to the use of puberty blockers and masculinising/feminising hormones, had already been shown to be weak. There was, and remains, a lot of misinformation easily accessible online, with opposing sides of the debate pointing to research to justify a position, regardless of the quality of the studies.

Conclusion

The Cass Review concludes that children and young people questioning their gender identity or experiencing gender dysphoria require a high standard of care that is safe, holistic, and evidence-based. The Review found that the evidence base for medical interventions, particularly puberty blockers and masculinising/feminising hormones, is weak, and that clinical practice has been complicated by a toxic, polarised public debate. The ten key recommendations focus on: (1) ensuring services meet standard NHS care standards with clear clinical leadership; (2) implementing holistic assessment frameworks including screening for neurodevelopmental conditions and mental health; (3) using standard evidence-based psychological and psychopharmacological treatments; (4) ensuring early clinical involvement in decisions about social transition of pre-pubertal children; (5-6) establishing robust research and data collection programmes to improve the evidence base; (7) requiring long-standing gender incongruence as essential but not sufficient for medical treatment; (8) exercising extreme caution in prescribing hormones from age 16; (9) requiring national Multi Disciplinary Team review for all medical treatment cases; and (10) offering fertility counselling and preservation before any medical pathway. The Review emphasises that the NHS must work in an evidence-based way rather than following a social justice model, and that the needs of vulnerable children and young people must be prioritised over ideological positions.