The UK is Restarting a Puberty Blocker Trial Despite 25 Years of Evidence - Carrie Clark (#4)
The NHS is pressing ahead with a £10 million puberty blocker study — the Pathways research programme — despite the Cass Review's damning verdict on two decades of practice at the Tavistock. Carrie Clark, Director of Genspect UK, joins Stella O'Malley and Mia Hughes to examine what the proposed trial gets wrong: its flawed scientific premises, the exclusion of detransitioners from consultations, the nine thousand former GIDS patients the NHS has declined to follow up, and the activist language embedded in the study's own design.
When the Cass Review concluded that the Gender Identity Development Service at the Tavistock had exposed thousands of children to treatments lacking an adequate evidence base, many in Britain hoped it marked a turning point. Carrie Clark, Director of Genspect UK, joins Stella O'Malley and Mia Hughes to examine why that hope may be premature. The NHS is now proposing a £10 million research programme known as the Pathways study — and Clark's analysis suggests it risks repeating the errors the Cass Review was commissioned to expose. The problems Clark identifies begin with the study's scientific foundations. Rather than starting from a position of genuine clinical uncertainty, the Pathways study appears to embed contested assumptions directly into its design — using activist-aligned language that prejudges the very questions the research is supposed to answer. Crucially, the proposed trial includes no robust exclusion criteria for young people with significant mental health difficulties or autism, despite those being exactly the populations whose complex needs were so poorly served by GIDS. The Dutch Protocol, often cited as the international benchmark for paediatric gender medicine, receives similar scrutiny: Clark argues that its methodology is far weaker than its reputation suggests. Perhaps the most sobering section of the conversation concerns the roughly nine thousand children who passed through GIDS before the clinic was closed. The NHS has declined to conduct systematic follow-up on those young people. Without knowing what became of them — whether they went on to transition, detransition, or live with lasting physical or psychological effects — any new study is building on a foundation that remains, deliberately or otherwise, incomplete. Detransitioners, whose experiences might have introduced essential corrective evidence, were also excluded from the formal consultation process that shaped the Pathways study's design. Two further cases deepen the concern. Tavistock's own Early Intervention Study, which might have offered a candid internal assessment of outcomes, produced results that Clark says were effectively suppressed rather than used to inform policy. A major American study by researcher Joanna Olson-Kennedy presents a comparable pattern: findings that were expected years ago remain unpublished, raising obvious questions about what the data show and why it has not been shared. For British listeners, the cumulative picture is troubling. The Cass Review gave the NHS both a mandate and a moral obligation to insist on honest, rigorous, independent evidence before exposing another generation of children to hormonal interventions. The Pathways study, as described here, does not yet meet that standard. Clark closes with a direct appeal for public engagement — arguing that the window to influence whether this trial proceeds, and in what form, is narrowing. Understanding exactly what is being proposed, and why it falls short, is the necessary starting point.
