The final report of the Cass Review is out
England's National Health Service commissioned this independent review, by pediatrician Hilary Cass, of the nation's just-closed pediatric gender care clinic and the research backing pediatric gender-transition treatment.
Learn more🧵⬇️
The Cass Review characterizes the medicalized approach to pediatric gender-transition treatment—one that all major US medical societies support, and which is centered around the prescription of puberty blockers and cross-sex hormones—as unsupported by sound scientific evidence.🧵
“There remains diversity of opinion as to how best to treat these...young people. The evidence is weak and clinicians have told us they are unable to determine with any certainty which children and young people will go on to have an enduring trans identity.” –The Cass Review
While the Cass Review is measured in tone, it nevertheless offers a scathing critique England’s erstwhile pediatric gender clinic's efforts to care for the fast expanding population of adolescents, in particular biological girls, burdened by severe gender-related distress.
The Cass Review was published in concert with a raft of peer-reviewed analyses of the evidence base and global treatment guidelines regarding pediatric gender medicine. Cass commissioned those studies from researchers at York University. adc.bmj.com/pages/gender-i…
Like previous systematic literature reviews, the York University reviews found the evidence backing pediatric gender-transition treatment wanting and largely of low quality. adc.bmj.com/pages/gender-i…
The Cass Review reports that research does *not* support the claim that puberty blockers and hormones reduce the elevated suicide death rate among gender-distressed youths. Thus the claim that pediatric gender-transition treatment is “life saving" is not evidence based.
“There is no simple explanation for the increase in the numbers of predominantly young people" identifying as transgender, "but there is broad agreement that it is a result of a complex interplay between biological, psychological and social factors." --The Cass Review
The Cass review acknowledges the NHS's recent decision to permit hormones for gender distressed youths starting at age 16. But Cass advises "extreme caution" and a "clear clinical rationale" for starting before age 18.
Cass advises that families considering social transitioning gender-incongruent children—changing a child’s name, pronouns, clothing, etc.—should take into account that this “may change the trajectory of gender identity development.”
The systematic literature review on puberty blockers found: “No conclusions can be drawn about the impact on gender dysphoria, mental and psychosocial health or cognitive development. Bone health and height may be compromised during treatment.” adc.bmj.com/pages/gender-i…
The systematic literature review on hormones for adolescents found: “Moderate-quality evidence suggests mental health may be improved during treatment, but robust study is still required. For other outcomes, no conclusions can be drawn.” adc.bmj.com/pages/gender-i…
The Cass report undermines the primary explicit purpose for puberty blockers, the argument waged by WPATH, American medical associations and others: that they afford children and their families more time to determine whether taking cross-sex hormones is the best option for them.
The Cass report is not simply grounded in systematic literature reviews. It is also based on the team’s years of routine interviews, meetings and focus groups with service providers, families and young people with gender distress, including people who have detransitioned.
“There are few other areas of healthcare where professionals are so afraid to openly discuss their views, where people are vilified on social media, and where name-calling echoes the worst bullying behaviour. This must stop.”
–Dr. Hilary Cass, the Cass Review
“Some practitioners abandoned normal clinical approaches to holistic assessment, which has meant that this group of young people have been exceptionalised compared to other young people with similarly complex presentations."
–Dr. Hilary Cass, the Cass Review
The Cass Review expressed dismay that England's pediatric gender clinic, GIDS, refused to share its data on the approximately 9,000 children that the clinic has seen since it began prescribing puberty blockers in 2011. This has thwarted Cass's efforts to improve services.
“Young people’s sense of identity is not always fixed and may evolve over time,” the Cass Review states. Whilst some young people may feel an urgency to transition, young adults looking back at their younger selves would often advise slowing down.”
The Cass Review, it states “is cognisant of the broader cultural and societal debates relating to the rights of transgender people. It is not the role of the Review to take any position on the beliefs that underpin these debates.”
Most pediatric gender transition treatment guidelines, the Cass Review states, acknowledge the “insufficient evidence about the risks and benefits” of such treatment. Nevertheless, “many then went on to cite this same evidence to recommend medical treatments.”
Cass faulted WPATH and the Endocrine Society for “circularity” in their citations to one another. WPATH “cited many of the other national & regional guidelines to support some of its recommendations." But these guidelines were “considerably influenced” by WPATH’s own guidelines.
While acknowledging that the evidence base behind psychological interventions for youth gender distress are weak, the Cass Review defends against accusations that anything less than a fully “affirmative” approach is tantamount to conversion therapy.
The recommendation from the Cass Review that “long-standing gender incongruence should be an essential prerequisite for medical treatment” suggests that the NHS puberty blocker clinical trial will exclude those with adolescent onset gender dysphoria.
The Cass Review speaks scornfully about the NHS’s recent decision to permit 16 and 17 year olds to access cross-sex hormones.
The new NHS youth gender clinics, the Cass Review states, "should include psychiatrists, paediatricians, psychologists, psychotherapists, clinical nurse specialists, social workers, specialists in autism..., speech and language therapists, occupational health specialists."
“This Review is not about defining what it means to be trans, nor is it about undermining the validity of trans identities, challenging the right of people to express themselves, or rolling back on people’s rights to healthcare,” writes Dr. Hilary Cass.
“We have to start from the understanding that this group of children and young people are just that; children and young people first and foremost, not individuals solely defined by their gender incongruence or gender-related distress.” –Dr. Hilary Cass
“We have to start from the understanding that this group of children and young people are just that; children and young people first and foremost, not individuals solely defined by their gender incongruence or gender-related distress.”
–Dr. Hilary Cass, the Cass Review
The Cass Review, it states “is cognisant of the broader cultural and societal debates relating to the rights of transgender people. It is not the role of the Review to take any position on the beliefs that underpin these debates.”
The Cass Review does not come down on any one side of the debate over whether trans identity is inborn, subject to a social-contagion effect, or is the result of any other particular factors. Instead, it suggests an "all of the above" and "it depends" framework.
On the very controversial subject of at what rate pre-pubescent children with early gender incongruence or distress will see this resolve and identify as their birth sex by adolescence, known as desisting, the Cass Review says that the desistance rate is apparently high.
The Cass Review expressed concerns that many of the same factors that have made caring for gender distressed children and adolescents so fraught and complex will likely remain true for young adults. So it recommends the NHS look at the service for that demographic as well.
The Cass Review insists that the needs of detransitioners--those who have medically transitioned to the opposite sex and who have reverted to identifying and presenting as their biological sex--must not be overlooked.
The Cass Review expressed concerns about young people turning to unregulated clinics to obtain puberty blockers now that the NHS has ceased prescribing them.
The Cass Review recommended clamping down on pharmacists' doling out puberty blockers now that the NHS has ceased newly prescribing them. (Minors currently on the drugs will be allowed to stay on them.)
This chart of the children and adolescents referred to the NHS's now-shuttered pediatric gender clinic, GIDS, demonstrates a common worldwide phenomenon: a surge of gender dysphoria and trans identification in about 2014, especially among biological girls.
This extended chart shows the continued surge in referrals to the NHS's pediatric gender clinic, GIDS, through 2021 to 2022, largely among older biological girls. (In the most recent years, they stopped reporting biological sex.)
The Cass Review had the following to say about the study published in February about the risk of suicide death among youths referred to gender clinics in Finland (which I covered for @NYPost-- ): nypost.com/2024/02/24/opi…
The Cass Review said that the dramatic change in the patient profile in those presenting with pediatric gender distress in England needs to be reflected by the services NHS offers.
The striking increase" in youth gender distress "needs to be considered within the context of poor mental health and emotional distress amongst the broader adolescent population, particularly given their high rates of co-existing mental health problems and neurodiversity."
The Cass Review suggests a connection between the youth mental health crisis overall and the influx of young people developing gender-related distress.
Nodding to the recent book by @JonHaidt, The Anxious Generation, the Cass Review points to a sudden rise in self harm in 13 to 16 year old girls in the early 2010s. This preceded the spike among biological girls identifying as trans.
The Cass Review ticks off various psychosocial factors that may drive trans identification in youth.
It is common to hear the argument that wide social acceptance is the sole reason for the recent rise in trans identification in youths. Activists often point to the supposed rise in left handedness after that stopped being scorned as a parallel. The Cass Review isn't convinced.
The new systematic literature review of the more than 20 pediatric gender care guidelines led the Cass Review to conclude that it could only recommend the Finnish and Swedish guidelines. WPATH and American Academy of Pediatrics got notably low scores.
The Cass Report says "it is important to view" social transitioning--changing name, pronouns, dress, hair, etc.--"as an active intervention because it may have significant effects on the child or young person in terms of their psychological functioning or longer-term outcomes."
The Cass Review reports that when gender-distressed children socially transition and keep their biological sex secret at school, this may drive them to want to go on puberty blockers to avoid "being found out".
Of the 11 available studies on social transition, nine were low quality, including @Jack_Turban 2022 and Olson 2016 and 2022; and two were moderate quality, including Steensma 2013 and Sievert 2021.
WPATH recently shifted from a cautious to an enthusiastic support for socially transitioning children. "However," the Cass Review states, "none of the WPATH 8 statements in favor of social transition in childhood are supported by the findings of the" systematic literature review.
The Cass Review differed sharply with WPATH, advising a "cautious approach" to socially transitioning children with gender incongruence or distress.
Cass Review finishes: "While open and constructive debate is needed, I would urge everybody to remember the children & young people trying to live their lives and the families/carers and clinicians doing their best to support them. All should be treated with compassion & respect.
Here is a working link for the multiple systematic literature reviews on which the English Cass Review of pediatric gender medicine was based. adc.bmj.com/content/early/…
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About Health Nerd's take-down of the Finnish study on mental health outcomes among youth attending gender clinics
🧵👇
The study isn't perfect by any means. There are fair reasons to criticize it. But Health Nerd's central thesis falls apart upon the simplest examination.
I find it very disappointing when people leverage their academic credentials to supposedly bust bad science or misinformation but only wind up spreading more misinformation in the process. Where are we these days if we can't trust people to use their credentials wisely and inspire trust in those with advanced degrees?
I've tried explaining to Health Nerd what he got wrong, to no avail. It was like arguing with a character in a Lewis Caroll poem.
Health Nerd's argument depends on redefining the study’s outcome variable as “how many times kids saw a psychiatrist for any problem.” No, that's not what the paper measures. It measures contacts with specialist-level psychiatric treatment. In Finland, that is referral-based care generally reserved for more serious mental illness. Milder mental health problems are handled in primary care. gidmk.substack.com/p/does-gender-…
That distinction between primary-care services and specialist psych care matters. It's the reason the authors use this variable in the first place. It's not a measure of casual or routine mental health visits.
Queer editor James Ball declares Bluesky a “dying social network,” blaming aggressive censoriousness by Blueskyites of perceived ideological enemies:
“There's a large cadre that basically cheers on chasing off any lib/centrist/academic who's the punchbag of the day. There's a culture of saying ‘fuck off back to X, then.’ And the anti- bedtime leftists set too much of the culture.
“I don't know if it's fixable, especially as I think quite a lot of the people here don't *want* to fix it. But at the rate users are quitting they'll run out of targets soon enough, and the rest of us will lose what is – for a fair few of us I suspect – the last fun/useful social network. Sigh.”
More from James about Bluesky’s demise:
The grim Bluesky stats. Turns out echo chambers are not big business.
This catalogue, which the World Professional Association for Transgender Health, or WPATH, fought to keep shielded, provides a rich account of how leading figures in pediatric gender medicine approached scientific research, drove the evolution of medical practices, and strategized politically during a critical turning point in this field’s brief and tortured history. The two years following Chase Strangio’s 2021 address were a period in which statehouse Republicans escalated their attacks on this field. The WPATH conference presenters largely responded to the political siege by doubling down. Rather than engage in soul searching over whether their methods in pediatrics were ethically sound and whether any criticisms had merit, they overwhelmingly stuck to their guns.
Presenters frequently downplayed fundamental hazards about irrevocably altering adolescents’ bodies. Meanwhile, a parade of systematic reviews—the gold standard of scientific evidence—was concluding that the evidencebacking pediatric gender medicine is weak and inconclusive. These findings have led health authorities in a number of European nations, concerned about risks such as infertility, to reverse course. They reclassified pediatric gender-transition interventions as experimental and sharply restricted minors’ access.
Not WPATH. The organization remained on an inexorable trajectory in the opposite direction, toward its eventual head-on collision with the second Trump administration.
For highlight clips, see the 🧵👇
Kellan Baker counseled against saying “gender-affirming care.” Messaging research indicated that when people hear it, he said, “they think ‘trans kids in the driver’s seat.’” But he said this was an accurate assessment. “I think we all support trans kids in the driver’s seat because it’s their bodies, it’s their lives,” he said.
“But when you think about folks who don’t know trans people, they are very scared by the idea that young people are making irreversible decisions and that no one else has any oversight over those decisions.”
To read my article in @CompactMag about the 100s of videos I obtained from the World Professional Association for Transgender Health (WPATH) and its US offshoot, USPATH: compactmag.com/article/how-ge…
Johanna Olson-Kennedy: “I think that a lot of this conversation...gets talked about through a lens of ‘How can we make sure people are really trans,’ right? And ‘They’re not going to regret their decision later?’” But “that’s actually not the discussion that I’m interested in participating in," she said. "I’m interested in discussing and having a conversation about giving the very best possible care to trans young people—the care that they need and deserve.”
To read my article in @CompactMag about the 100s of videos I obtained from the World Professional Association for Transgender Health (WPATH) and its US offshoot, USPATH: compactmag.com/article/how-ge…
🧵👇Debunking podcaster Michael Hobbes is wrong about the American Medical Association’s longstanding position about youth gender surgeries.
Before Feb. 2026, the AMA had never specified that gender surgeries should generally be reserved for adults.
In 2024, the AMA asserted: “Our American Medical Association recognizes that medical and surgical treatments for gender dysphoria and gender incongruence, as determined by shared decision making between the patient and physician, are medically necessary as outlined by generally-accepted standards of medical and surgical practice.”
Hobbes is pointing to this WPATH FAQ without acknowledging (or knowing) that it actually misrepresents what the organization’s trans-care guidelines, The Standards of Care Version 8 (SoC 8) says. WPATH famously removed all age limits (except for phalloplasty) in the SoC 8 when it was published in Sept 2022 under pressure from the American Academy of Pediatrics.
Hobbes fails to understand that the original reporter who published the AMA’s statement saying it sided with the ASPS on youth gender surgeries was not Jeremy Peters, it was Andrew Jacobs, who could in no way be considered a part of this supposed “anti-trans braintrust.” Peters was only reiterating what Jacobs originally reported.
And yes, the statement was a shift, otherwise the AMA wouldn’t be trying to walk it back and say they were misquoted. Because the AMA knows that the statement reads as if they did make a shift in policy.
Is the AMA Telling the Truth About Their Expressed Positions on Youth Gender Surgeries?
The American Medical Association to the @StrackHaley at the National Review @NRO on Feb. 3: "[T]he AMA agrees with ASPS that surgical interventions in minors should be generally deferred to adulthood."
The @AmerMedicalAssn today: "We responded" to questions about the American Society of Plastic Surgeon's opposition to pediatric gender-transition surgeries "only after being contacted by media outlets, using the language approved by the board. While some media coverage characterized this as agreement with the ASPS statement, that phrasing did not come from the AMA."
Meghan Wachspress, who accused Illinois congressional candidate Daniel Biss of an "inappropriate relationship" after he, at 26, was her math prof and she, 20, was his student and the 2 dated for a while and made out in '04, wrote on Substack in 2025 that MeToo didn't go far enough.
"In an alternate universe the experiences encompassed by #metoo could have expanded outward to include other kinds of workplace interactions and structural inequalities that minimized or objectified women in the Kantian sense (making them men’s tools), costing women status, money, and time compared to their male colleagues," she wrote. substack.com/home/post/p-16…