Tavistocks blokkerstudie fant ingen psykologisk fordel – likevel gikk 98 % videre til hormoner for motsatt kjønn

Kortsiktige utfall av pubertetsundertrykking i en utvalgt kohort av 12–15 år gamle unge med vedvarende kjønnsdysfori i Storbritannia

Authors
Polly Carmichael, Gary Butler, Una Masic, Tim J. Cole, Bianca L. De Stavola, Sarah Davidson, Elin M. Skageberg, Sophie Khadr, Russell M. Viner
Journal
PLOS ONE
Year
2021

Summary

This was the UK's own test of puberty blockers, run by the Tavistock's gender clinic for children from 2011. Forty-four carefully chosen 12–15-year-olds were given a blocker drug and followed until they were over 16. The blockers paused puberty as intended. But there was no measurable change in emotional distress, self-harm, quality of life or gender distress, and bone density fell behind other teens their age. Most young people spoke positively about the treatment in interviews, and 43 of 44 went on to cross-sex hormones. The authors call for larger studies. There was no comparison group, numbers fell sharply after the first year, and a later re-analysis found up to a third got worse. So the study offers no evidence that blockers help mental health.

Key findings

  • 44 unge i alderen 12–15 år (25 født som gutter, 19 født som jenter) med alvorlige, langvarige kjønnsplager begynte på en pubertetsblokker mellom 2011 og 2015, etter typisk to års vurdering ved klinikken.
  • Verken foreldre eller de unge rapporterte noen endring i emosjonelle problemer eller atferdsproblemer, eller i selvskading, etter 1, 2 eller 3 år.
  • Livskvalitet, følelser om kroppen sin, kjønnsplager og hvor godt de taklet ting (slik klinikere vurderte det) endret seg også lite. Forfatterne bemerker at blokkere ikke endrer kroppen mot ønsket kjønn.
  • Beintettheten i korsryggen vokste saktere enn hos andre tenåringer, så den falt bak for alderen, og høydeveksten ble også saktere.
  • Forventede bivirkninger som hodepine, hetetokter og tretthet var vanlige. 38 % sa at de hadde lite energi i intervjuer etter 15–24 måneder.
  • 43 av 44 (98 %) gikk videre til kryssjønnede hormoner, i tråd med det nederlandske funnet om at nesten ingen slutter etter blokkere.
  • Bare 24 unge var fortsatt med i dataene etter 2 år og 14 etter 3 år (med bare 6 som fylte ut egne spørreskjemaer etter 3 år), så det kan sies lite om mer langsiktige effekter.
  • En ny analyse av de samme dataene i 2024 av McPherson og Freedman fant at 15–34 % av de unge tydelig fikk det verre, avhengig av målet, tidspunktet og hvem som rapporterte.

Abstract

BACKGROUND: In adolescents with severe and persistent gender dysphoria (GD), gonadotropin releasing hormone analogues (GnRHa) are used from early/middle puberty with the aim of delaying irreversible and unwanted pubertal body changes. Evidence of outcomes of pubertal suppression in GD is limited. METHODS: We undertook an uncontrolled prospective observational study of GnRHa as monotherapy in 44 12-15 year olds with persistent and severe GD. Prespecified analyses were limited to key outcomes: bone mineral content (BMC) and bone mineral density (BMD); Child Behaviour CheckList (CBCL) total t-score; Youth Self-Report (YSR) total t-score; CBCL and YSR self-harm indices; at 12, 24 and 36 months. Semistructured interviews were conducted on GnRHa. RESULTS: 44 patients had data at 12 months follow-up, 24 at 24 months and 14 at 36 months. All had normal karyotype and endocrinology consistent with birth-registered sex. All achieved suppression of gonadotropins by 6 months. At the end of the study one ceased GnRHa and 43 (98%) elected to start cross-sex hormones. There was no change from baseline in spine BMD at 12 months nor in hip BMD at 24 and 36 months, but at 24 months lumbar spine BMC and BMD were higher than at baseline (BMC +6.0 (95% CI: 4.0, 7.9); BMD +0.05 (0.03, 0.07)). There were no changes from baseline to 12 or 24 months in CBCL or YSR total t-scores or for CBCL or YSR self-harm indices, nor for CBCL total t-score or self-harm index at 36 months. Most participants reported positive or a mixture of positive and negative life changes on GnRHa. Anticipated adverse events were common. CONCLUSIONS: Overall patient experience of changes on GnRHa treatment was positive. We identified no changes in psychological function. Changes in BMD were consistent with suppression of growth. Larger and longer-term prospective studies using a range of designs are needed to more fully quantify the benefits and harms of pubertal suppression in GD.

Conclusion

Treatment with GnRHa was efficacious in suppressing pubertal progression; anticipated effects of sex-hormone withdrawal were common and there were no unexpected adverse events. BMD increased in the lumbar spine and was stable at the hip, while BMD z-scores fell, consistent with delayed puberty. Overall participant experience was positive, but the authors identified no changes in psychological function, quality of life or degree of gender dysphoria. The great majority went on to cross-sex hormones; one did not, which the authors took as evidence that gender identity development continues on GnRHa. Larger, longer-term studies using a range of designs are needed to quantify benefits and harms.