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Dutch rollout

Peggy Cohen-Kettenis's VUmc team developed the Dutch Protocol in the 1990s. It was adopted worldwide based on a cohort of only 70 patients — including one concealed death. Today, ZonMw, Amsterdam UMC, and the scientific societies actively deny Cass. Institutional capture in its most persistent form: a small country that has heavily medicalized the world and refuses to acknowledge it.

VUmc 1987–2014: the origins

Peggy Cohen-Kettenis started a gender clinic at the Vrije Universiteit in 1987. She combined puberty blockade (later triptorelin) with cross-sex hormones around age 16 and surgery around age 18. The cohort was carefully selected: early onset, no severe psychiatric comorbidity, stable family situation — predominantly boys. Publications by De Vries and Cohen-Kettenis (2011, 2014) reported positive outcomes in 55 of the 70 originally selected adolescents. What was barely made visible in both papers: one participant died perioperatively from a complication of vaginoplasty. The study continued. See VUmc protocol criticism for the full methodological analysis.

International transfer: a small cohort to a global standard

The protocol was adopted internationally starting in 2007: Boston Children's, Tavistock GIDS, Karolinska, and ultimately in WPATH SOC7 (2012) . Crucial problem: the protocol was applied to patient populations—particularly adolescent girls with late-onset dysphoria and severe comorbid psychopathology—for which it was never designed or validated. See the social media explosion and ROGD . The Cass Review (2024) calls this key point: the Dutch studies "research not robust" and scaled up globally without testing.

The Dutch cohort under fire

In 2022–2023, Michael Biggs and others published reanalyses pointing to selection bias, a missing control group, the concealed death during follow-up, and post-hoc selected outcome measures. Stephen Levine ( Journal of Sex & Marital Therapy , 2023) and the Cass Review (2024) confirmed that the Dutch results are not replicable (Karolinska failed) and do not meet modern standards of evidence. The WPATH Files (2024) show that WPATH clinicians shared the same doubts internally—but publicly defended the dogma.

Current Dutch situation: institutional capture

Amsterdam UMC (successor to VUmc), Radboudumc, and UMCG still offer gender-affirmative care following a slightly modified SOC8 framework. ZonMw has been working on a revision since 2024; the composition of the committee indicates continuity with the affirmative school. The Federation of Medical Specialists and the Knowledge Table on Transgender Care actively deny Cass — an institutional reflex that illustrates how deeply the ideological belief in "true identity" is entrenched. Critical clinicians (even internationally recognized sexologists) are silenced and collegially isolated.

Since 2014, the Transgender Act (BW 1:28) has permitted the change of gender registration following an expert statement. A legislative proposal without such a statement (Yesilgöz/Dijkstra, 2023, inspired by the Yogyakarta Principles ) is still pending in the Senate. An important comparison: while Scandinavia and the US are rolling back, the Netherlands belongs to the group — along with Germany, Belgium, and France — that clings to the dogma. Small country, major export of damage.

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