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

• 報告由 NHS England 於 2020 年設立，並在 2024 年 4 月 10 日發表，共 388 頁，針對英格蘭兒童與青少年的性別服務提出 32 項建議。
• 約克大學對青春期阻斷劑的回顧檢視了 50 項研究（1 項高品質、25 項中等、24 項低品質）。回顧指出，對於性別困擾、心理健康或腦部發育的影響無法得出結論，而骨骼健康和身高可能受到損害。
• 約克大學對跨性別荷爾蒙的回顧檢視了 53 項研究（1 項高品質、33 項中等、19 項低品質）。回顧發現有中等品質的證據顯示治療期間心理健康可能改善，但對其他影響無法得出結論。
• 檢討報告建議進行全人評估，包括檢查是否有自閉症及類似狀況與心理健康評估，並以標準且經證實的談話治療和藥物來處理痛苦和其他狀況。
• 青春期阻斷劑只應在研究中提供（NHS England 已推動一項試驗）。16 歲起使用荷爾蒙需要「極度審慎」，並且要有明確理由說明為何不等到 18 歲，而且每一個醫療處置的個案都應送交國家專家小組。
• 檢討報告發現，包括 WPATH（世界跨性別健康專業協會）在內的指引並不是經過審慎制定的。七家 NHS 成人性別門診中有六家拒絕分享長期結果研究所需的資料，報告表示應該要求它們參與。
• 為年幼孩子決定社會性過渡（新名字、衣著或代名詞）的家庭，應及早諮詢有經驗的臨床人員，所有年輕人在接受任何醫療處置前，都應獲得生育諮詢以及卵子或精子保存的機會。
• 報告受到耶魯 Integrity Project（McNamara 等人，2024）和一篇經同儕審查的論文（Noone 等人，2025）批評。《兒童疾病檔案》（Cheung 等人，2025）和《性與婚姻治療期刊》（McDeavitt 等人，2025）則為報告辯護。

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.