A look at “Re-examining the Cass Review: A critical commentary on gender diversity research” by Cora Sargeant, Dan O’Hare, Beckett Markland and Sarah Wright (2026)
Few documents have shaped the conversation about gender diverse young people in the UK quite like the Cass Review, published in 2024. It was welcomed across the political spectrum and became the basis for major changes to NHS gender services. This commentary, by a team of educational psychologists who research gender diversity, argues that it deserves a much more critical reading. This is a topic where feelings run high, so we’ve tried to tread carefully: no glitter cannons, just a few gentle sparkles.
What it argues
Gender diversity is real, historic and joyful. The authors begin by reminding readers that gender diverse people have existed across cultures and throughout history. They point out that trans experience isn’t only about distress (gender dysphoria) but also about gender euphoria: the elation of being seen as who you are.
The Cass Review’s evidence choices are contested. The Review drew on systematic reviews by the University of York, which judged much of the evidence for puberty blockers and hormones to be low quality. The authors argue that some of these reviews excluded relevant studies and, in places, misread them. Their key example concerns social transition. A large US study found that the higher suicide risk linked with adolescent social transition disappeared once harassment was taken into account. The authors argue that bullying, not transition, was the problem, and that the York review didn’t make this clear.
The UK is out of step internationally. The authors note that the Review’s conclusions differ from the guidance of several international and professional bodies. They also point out that the UK government went further than Cass recommended by indefinitely banning routine prescribing of puberty blockers for gender-related distress.
Young people are paying the price. They describe waits of over two years for a first appointment at gender services, alongside high rates of bullying, discrimination and isolation.
Psychologists can help. Educational psychologists, they argue, are well placed to support gender diverse young people in schools by challenging rigid gender norms, amplifying young people’s voices and helping schools become places where they can belong.
A grain of glitter ✨
This is a passionate, carefully referenced commentary that raises serious questions. But it’s important to be clear about what it is.
It’s a commentary, not a systematic review, and the authors say openly that they write as advocates for gender diverse young people. The Cass Review’s supporters point out that the York reviews used established, transparent methods for judging evidence quality. Other researchers have published detailed rebuttals of the critiques the authors draw on, and the authors cite one of these. Reasonable experts continue to disagree sharply about how to interpret a limited evidence base, and the policy landscape has kept shifting. As of early 2026, a planned NHS research trial of puberty blockers had been paused. Readers should treat this paper as one side of a live and polarised debate rather than the final word.
Why this matters
If you’re a gender diverse young person, a parent, or an adult reflecting on your own journey, the noise around this topic can be exhausting and frightening. Whatever your views on medical questions, one thing isn’t in dispute: gender diverse people deserve to feel safe, heard and supported, at school, at home and in therapy. A good therapist won’t push you in any particular direction. They’ll help you explore who you are, at your own pace, without judgement.
Every unicorn deserves a paddock where it can simply be itself.