Tavistocks blockerarstudie fann ingen psykologisk nytta – ändå gick 98 % vidare till könsöverskridande hormoner

Kortsiktiga utfall av pubertetsbromsning i en utvald kohort av 12–15-åriga unga med bestående könsdysfori i Storbritannien

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 unga i åldern 12–15 (25 födda som pojkar, 19 födda som flickor) med svårt, långvarigt könsrelaterat lidande började med en pubertetsblockerare mellan 2011 och 2015, efter typiskt två års bedömning vid kliniken.
  • Varken föräldrar eller de unga rapporterade någon förändring i känslomässiga problem eller beteendeproblem, eller i självskada, efter 1, 2 eller 3 år.
  • Livskvalitet, känslor kring kroppen, könsrelaterat lidande och hur väl de klarade sig (bedömt av kliniker) förändrades också lite. Författarna noterar att blockerare inte förändrar kroppen mot det önskade könet.
  • Bentätheten i ländryggen växte långsammare än hos andra tonåringar, så den halkade efter för deras ålder, och längdtillväxten saktade också in.
  • Förväntade biverkningar som huvudvärk, värmevallningar och trötthet var vanliga. 38 % sa att de hade låg energi i intervjuer efter 15–24 månader.
  • 43 av 44 (98 %) gick vidare till korskönshormoner, i linje med det nederländska fyndet att nästan ingen slutar efter blockerare.
  • Bara 24 unga fanns kvar i data efter 2 år och 14 efter 3 år (med bara 6 som fyllde i sina egna frågeformulär efter 3 år), så lite kan sägas om långsiktiga effekter.
  • En ny analys 2024 av samma data av McPherson och Freedman fann att 15–34 % av de unga tydligt fick det sämre, beroende på mått, tidpunkt och vem som rapporterade.

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.