Researchers find current evidence for puberty blockers and hormone treatment for gender transition is inadequate

The evidence on the use of puberty blockers and hormones for children and young people experiencing gender related distress is wholly inadequate, making it impossible to gauge their effectiveness or their impact on mental and physical health, find two systematic reviews of the available research, published in the Archives of Disease in Childhood.

Of the 50 studies included in the review looking at the effectiveness of puberty blockers for gender questioning teens, only one was of high quality, leading the authors to conclude that although most of the studies suggested that treatment might affect bone health and height, "No conclusions can be drawn about the impact on gender dysphoria, mental and psychosocial health or cognitive development."

Similarly, of the 53 studies included in the review on the use of masculinizing and feminizing hormones, only one was of sufficiently high quality, with little or only inconsistent evidence on key outcomes, such as body satisfaction, psychosocial and cognitive outcomes, fertility, bone health and cardiometabolic effects.

Equally concerning is that most of the 23 clinical guidelines aren't independent or evidence based, concludes another review in the series. The links between the evidence and the recommendations are often unclear, and largely informed by two international guidelines (World Professional Association for Transgender Health and Endocrine Society) which themselves lack scientific rigor, say the authors.

A fourth review notes that while the guidelines agree on the need for psychosocial support, there's no consensus on who should be involved in providing this, or whether provision should be different for children and teens. And there's virtually no guidance on how best to support those who've not yet reached puberty or whose identity is non-binary.

The reviews comprise a series commissioned from the University of York to inform today's independent review into specialist services for the increasing numbers of children and young people referred with gender dysphoria—distress caused by a mismatch between birth sex and gender identity.

In an interview with The BMJ ahead of the report's publication, Dr. Hilary Cass, its author, points out that there's no evidence to suggest that puberty blockers help children and young people "buy time to think" or improve their psychological well-being.

"The only thing that we can tangibly say is that, particularly for the birth registered males, if you stop them breaking their voice and growing facial hair, then they may pass better in adulthood. But even that is not without qualification," she explains.

Cass also acknowledges that there was a point when "practice did deviate from the clinical evidence" and adds "there unfortunately is no evidence that gender affirming treatment in its broadest sense, reduces suicide risk."

She believes young people have been "let down" by the health system and society and insists that gender questioning children and young people seeking help from the NHS must be able to access a broad-based holistic assessment delivered by a multi-professional team including pediatricians, child psychiatrists, and allied health experts.

"Having that breadth means you can develop a proper plan and have the right people on hand to deal with it," she says.

Asked what she would say to children and young people, their families and caregivers, she replies, "We need to listen to them. We need to explain the weaknesses of the evidence. But most importantly, we need to find ways to help them feel better about themselves so that they're not going to be so distressed."

In an opinion piece for The BMJ, the dearth of good quality evidence prompts Cass to conclude that gender medicine is "built on shaky foundations."

She explains how care will now be delivered through a network of regional centers working collaboratively to the same clinical protocols, with research and data collection embedded from the outset.

"Regardless of whether or not [children and young people] choose a social or medical transition in the longer term, they need support to help them thrive and fulfill their life goals," she writes.

"I very much hope that this strong multidisciplinary team model, with networked service delivery and embedded research will encourage more clinicians with experience in child and adolescent health to work in this evolving area of clinical practice," she concludes.

In a linked editorial to accompany the reviews in Archives of Disease in Childhood, Dr. Camilla Kingdom, outgoing President of the Royal College of Paediatrics and Child Health, explains, "This group of children and young people are particularly vulnerable because their health and well-being needs are simply not being met.

"We have an overarching holistic approach to the care of babies, children and young people centered on their needs, which until now, has not percolated through to gender service provision. We now have an important opportunity to make up for lost time."