Cass vs France
The French Society of Pediatric Endocrinology and Diabetology commissioned its own version of the Cass Review, unsurprisingly it almost completely contradicts Cass.
by Veronica Esposito
Since its release last spring, the Cass Report has been a subject of great controversy. Originally commissioned by the UK’s National Health Service to evaluate the scientific evidence for medical gender transitions of those under 18, it reached a series of recommendations that essentially indicated that medical transition for transgender youth should be all but eliminated.
The findings of Cass have been embraced by the English government and used to justify the elimination of transition services for minors, while elsewhere it has been very heavily critiqued: a Yale Law School “evidence-based critique” of the Cass Review rebutted nearly every major conclusion of Cass, The Royal Australian and New Zealand College of Psychiatrists rejected implementation of Cass in Australia, and many other research teams have offered in-depth debunkings and rebuttals.
The French Society of Pediatric Endocrinology and Diabetology (SFEDP) recently commissioned its own version of the Cass Review, and this study reached almost the exact opposite conclusions of Cass:
To put it in more familiar terms, SFEDP concluded in favor of the use of puberty blockers and cross-sex hormone replacement therapy for trans youth, recommended providing trans youth with non-medical forms of support such as name and pronoun changes and peer groups, and affirmed the importance of providing youth with fertility options before pursuing medical transition.
How did two European nations just a short tunnel ride away from one another come to such completely opposite conclusions regarding transgender youth? And just what does each review say about the major questions confronting trans minors and their families? Read on for some answers.
The Gender-Affirmative Model
Upon reading both the Cass Review and the SFEDP Review, what immediately jumps out is the very different tone of each—Cass takes a tone that feels skeptical to the point of excess, offering mysteriously curt phrasing, statements rife with implications of harm or conspiracy by mainstream providers, and an overall sense of invalidation. By contrast, the SFEDP Review reads like a scientific paper—its language is straightforward and sterile, and there is none of the innuendo of Cass. Reading both side by side feels almost like traveling from a land of paranoia and conspiracy into levelheaded reality.
These basic differences in language imply very different approaches to working with trans minors—gender-affirming vs gender-critical.
The gender-affirming model of supporting trans youth emerged in the late 1990s, eventually becoming the ascendent form of care; this is for good reason, as it is the only model with empirical evidence supporting good outcomes for trans children and adolescents. This model is widely approved of by major medical organizations in the U.S. and globally.
The opposite model of care could be termed “gender-critical,” which essentially seeks to dissuade minors from holding a trans identity and is in league with conversion therapy. This model is highly discredited and has been shown to lead to disastrous outcomes for trans minors. Midway between these approaches is the “watchful waiting” model, in which neither affirmative nor critical treatment is given.. This model predominated before gender-affirming care, and is also now generally discredited.
In a 2018 statement on medicine for trans minors (reaffirmed in 2023), the American Academy of Pediatrics distinguished watchful waiting from gender affirmation:
Accordingly, research substantiates that children who are prepubertal and assert an identity of TGD know their gender as clearly and as consistently as their developmentally equivalent peers who identify as cisgender and benefit from the same level of social acceptance. This developmental approach to gender affirmation is in contrast to the outdated approach in which a child’s gender-diverse assertions are held as “possibly true” until an arbitrary age (often after pubertal onset) when they can be considered valid, an approach that authors of the literature have termed “watchful waiting.” This outdated approach does not serve the child because critical support is withheld. Watchful waiting is based on binary notions of gender in which gender diversity and fluidity is pathologized.
The SFEDP Review comes out firmly in favor of the gender-affirmative approach, stating,
It further recommends that an interdisciplinary team of specialists trained in mental health, endocrinology, fertility, and other areas be amassed to best support a trans youth who undertakes medical transition.
By contrast, the Cass Review strikes a combative note from the outset, leveling unsupported accusations that the gender-affirmative model is based not on science but on left-wing social justice:
In a section titled, “Understanding the patient cohort,” the Cass Review suggests that minors may identify as transgender due to such things as neurodivergence, mental health problems, “peer influence,” and the Internet. Such reasoning aligns the Cass Review with the watchful waiting or even gender-critical models, as it undermines and invalidates trans identities, and it is also contrary to the available scientific evidence, which largely sees transness as inborn. It places the Cass Review firmly away from the gender-affirming model.
Puberty Blockers
Puberty blockers are widely viewed as an entry point to a medical transition for transgender minors who are entering adolescence. Although trans minors could move directly to taking cross-sex hormones once they wanted to transition, they have become a common part of the medical pathway for early adolescents as a means of pausing puberty long enough for a child, their doctors, and their parents to all get on the same page regarding transition.
The Cass Review takes a very dismissive tone regarding puberty blockers. It rejects most studies of blockers as of “poor quality,” and it recommends very limited use of the medication:
Notably, this is a drastic revision of how puberty blockers have been used with transgender children in the U.S., and a departure from the stated policies of major medical organizations worldwide. For instance, the American Academy of Pediatrics states the exact opposite: “The available data reveal that pubertal suppression in children who identify as TGD generally leads to improved psychological functioning in adolescence and young adulthood.” No mention of such statements is made in the Cass Review.
Cass also bizarrely states that “transgender males masculinise well on testosterone, so there is no obvious benefit of puberty blockers in helping them to ‘pass’ in later life,”—seemingly, forgetting that without puberty suppression trans males will develop breasts, requiring a major invasive surgery to correct. This omission is even stranger in light of the very considerable space that the Cass Review dedicates to worrying about the increase of birth-assigned females presenting for gender-affirming medical care.
The SFEDP Review strikes a very different tone on puberty blockers:
Where SFEDP notes that puberty suppression has been used for trans minors since the 1990s, Cass characterizes it as a “more recent” development (despite elsewhere noting research as far back as 1998).
Regarding the impacts on mental health of receiving puberty blockers, SFEDP also comes out in the exact opposite direction of Cass:
Social Transition
In the social transition section, Cass states outright falsehoods, such as the debunked research of Dr. Kenneth Zucker, who claimed that as many as 80% of transgender children desisted, or that “in those with DSD in whom gender identity outcome is less well established, the sex of rearing is a better predictor of gender identity outcome than prenatal androgen exposure.”
In spite of these missteps, Cass recommends that children be validated in their gender and allowed to pursue a social transition as desired. However, she does offer some scare language, such as baselessly implying that socially transitioning may lock a child into pursuing medical transition (there is no evidence of this and much to the contrary); she also makes this transphobic recommendation:
Essentially, even if a child desires a more robust social transition, parents and clinicians should stifle it in case they later change their mind. Such reasoning puts trans children into an impossible double bind: either they pursue medical transition and are seen as having prematurely locked themselves into a medical pathway, or they desist and prove that being trans is just a fad.
By contrast, SFEDP offers no scare language about potential regret or feeling pressured; rather, the authors simply provide helpful information on legally changing names, puberty-induced conditions such as acne, voice and communication instruction, and tucking and binding.
Cross-sex Hormones
In the sections on masculinizing and feminizing hormones, Cass attempts to invalidate the improvements to mental wellbeing experienced by trans minors by claiming that “a short-term boost in mental wellbeing is to be expected when sex hormones are introduced.” She also repeats the baseless claim that being trans could be a result of trauma, stating, “in some instances a range of adverse childhood experiences and stressors could lead to gender-related distress.”
Cass also tosses out most of the evidence in favor of HRT by claiming it is of “low quality.” The Yale Law School critique of Cass is particularly incredulous in this case:
Yale also notes that nowhere does Cass explore the sizable harms of not providing medical interventions to trans youth.
In this section, Cass seems to play particularly fast and loose with the facts, finding various methodological reasons to invalidate numerous studies linking HRT and reduced suicidality, yet giving nearly an entire page to two papers by Lisa Littman and Eli Vandenbussche on detransition, despite significant flaws in these papers. The web communities these studies recruited from were “overwhelmingly frequented by detransitioned women who were white, trans-exclusionary radical feminists.” Recruiting from such spaces would offer a biased view of detransition and would be important information for Cass to include, especially since she is so harsh on the methodology of research favoring transition.
It is also strange that Cass offers essentially the same amount of space to suicidality and detransition, despite her own data showing that less than 10 of the 3,499 youth served by the NHS detransitioned. It is unknown precisely how many trans children in the care of the NHS ended their own life, however there is evidence that the number is significant and that Cass and others took efforts to hide a spike in suicide among trans youth in the UK due to long wait times for gender services.
Overall, Cass’s intention in this section seems to be to sow confusion over the desirability of HRT for trans minors—she mostly dismisses studies finding benefits of HRT and highlights studies that find no or negative effects. The closest she comes to a recommendation for or against HRT is the following:
However, later in the document Cass all but says that HRT should be unavailable to anyone under 18:
The SFEDP Review offers none of the scare language of the Cass Review in its HRT section. Rather, it states that international consensus is to provide HRT to adolescents diagnosed with gender incongruence who want it, and provides detailed, highly technical information on the ins and outs of prescribing testosterone and estrogen.
Notably, SFEDP takes it as a given that adolescents with sufficient emotional maturity can provide informed consent for hormonal treatment. In contrast, Cass heavily implies that trans youth and their families lack the capacity to meaningfully consent to transitional-related treatment. This is contrary to general consensus, which finds that trans youth and their families can meaningfully make choices around gender-affirming care, in spite of the unavoidability of unknowns in the process. It should also be noted that acts like attaining a driver’s licence, taking antidepressants (which are often prescribed to minors after a single medical appointment), and taking birth control and being sexually active all have potentially unforeseeable and lifelong impacts, yet teens and their families make decisions about these things all of the time.
Cass as an Outlier
When considering the Cass Review within the larger context of treatment for trans youth worldwide, the document is an outlier. Many other bodies have reviewed essentially the same scientific evidence and reached the opposite conclusions.
Earlier this year, Germany’s Association of Scientific Medical Societies did its own review of the evidence and again refuted Cass, to the chagrin of one anti-trans hate group. As a 2017 map from the European Union makes clear, affirmation of trans children is the rule throughout Europe, and disaffirmation is the exception. Although Norway and Sweden have limited such care since this map was created, it’s still widely accessible there, with Finland as the only European nation we could find that has adopted UK-style restrictions since 2017. (Assigned Media earlier reported on the bizarre practices in youth treatment in Finland, led by Dr. Riittakerttu Kaltiala, who has advocated against the affirmative model.) In banning puberty blockers for transgender children and restricting the use of hormones, the UK stands opposite the vast majority of Europe, as well as Australia, Canada, Japan, and elsewhere.
The gender-affirming model of care did not come out of a vacuum—other models more aligned with the Cass Review were tried in the decades prior, and they were found to be failures. That is why gender-affirmation is still the predominant model. Ironically, the Cass Review calls for generating the exact evidence into gender-affirming care that already exists:
The overarching conclusion from the evidence presented in this Review is that the puberty blocker trial, which is already in development, needs to be one part of a much broader research programme that seeks to build the evidence on all potential interventions, and to determine the most effective way of supporting these children and young people.
Perhaps nowhere is the difference between the Cass Review and the SFEDP Review more clear than here: Cass bemoans the lack of good evidence and recommends generating it, whereas SFEDP declares that it is ready to follow the science by supporting minors in their transition. One cannot help but suspect that even if further research is conducted, in another 20 years another Cass will come along and demand another round of research into trans youth.
Veronica Esposito (she/her) is a writer and therapist based in the Bay Area. She writes regularly for The Guardian, Xtra Magazine, and KQED, the NPR member station for Northern California, on the arts, mental health, and LGBTQ+ issues.