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

• Rapporten ble satt i gang av NHS England i 2020 og publisert 10. april 2024. Den 388 sider lange sluttrapporten kommer med 32 anbefalinger for kjønnstjenester for barn og unge i England.
• Gjennomgangen fra University of York av pubertetsblokkere så på 50 studier (1 av høy kvalitet, 25 av moderat, 24 av lav). Den sa at det ikke kunne trekkes noen konklusjoner om effekter på kjønnsplager, psykisk helse eller hjerneutvikling, og at beinhelse og høyde kan bli skadet.
• Yorks gjennomgang av kryssjønnede hormoner så på 53 studier (1 av høy kvalitet, 33 av moderat, 19 av lav). Den fant evidens av moderat kvalitet for at psykisk helse kan bli bedre under behandlingen, men ingen konklusjoner kunne trekkes om andre effekter.
• Gjennomgangen anbefaler helhetlig vurdering av personen, inkludert undersøkelse for autisme og lignende tilstander og en psykisk helsevurdering, med vanlige, utprøvde samtaleterapier og medisiner mot plager og andre tilstander.
• Pubertetsblokkere bør bare gis innenfor en forskningsstudie (NHS England tok en utprøving videre). Hormoner fra 16 år krever «ytterste forsiktighet» og en klar grunn til ikke å vente til 18, og alle saker om medisinsk behandling bør legges frem for et nasjonalt ekspertpanel.
• Gjennomgangen fant at retningslinjer, inkludert WPATHs (World Professional Association for Transgender Health), ikke var omhyggelig utviklet. Seks av syv NHS-kjønnsklinikker for voksne nektet å dele data til en studie av langtidsresultater, og gjennomgangen sier at de bør pålegges å delta.
• Familier som skal bestemme seg for sosial overgang (nytt navn, klær eller pronomen) for små barn bør treffe en erfaren kliniker tidlig, og alle unge bør tilbys fertilitetsrådgivning og lagring av egg eller sæd før noen medisinsk behandling.
• Rapporten ble kritisert av Yales Integrity Project (McNamara og kolleger, 2024) og i en fagfellevurdert artikkel (Noone og kolleger, 2025). Den ble forsvart i Archives of Disease in Childhood (Cheung og kolleger, 2025) og Journal of Sex & Marital Therapy (McDeavitt og kolleger, 2025).

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.