One of the most important questions that science can answer is “does this medical treatment work?”. In an ideal world, scientists would be able to tackle this question objectively and dispassionately, and impartial science communicators would summarise the available evidence in a fair and balanced way.

We do not, of course, live in an ideal world — and the truth about medical treatments can often be clouded by ideology, passionate beliefs or deliberate misinformation. This is often because questions that may appear to be narrow matters of fact turn out to be intimately linked with identities. So, the issue of whether dexamethasone cures Covid became a matter of political identity (particularly once President Trump championed it). Similarly, homeopathy is about much more than just believing that highly dilute solutions of certain substances can cure diseases. Homeopaths sign up to a philosophical worldview at odds with mainstream medicine and science in profound ways.

I discovered myself just how strong feelings can be when I made a BBC Science film which explained why homeopathy is very unlikely to be effective. In response, a French scientist (once highly regarded) wrote me a letter suggesting my blood be used as a cure-all (a homeopathic in-joke since the more toxic the substance the more effective it is as a treatment when prepared homeopathically).

The interplay of medicine and identity perhaps explains why the most poisonous of all topics is that of transgender medicine

The interplay of medicine and identity perhaps explains why currently the most poisonous of all topics is that of transgender medicine. This is a subject where identity is at the very heart of the issue. How we should treat people with gender dysphoria (particularly children and adolescents) has become a highly charged area where mere evidence plays second fiddle to which side of the ideological divide you’re on. Nowhere is the toxicity of this issue more clearly shown than in the goings-on at the Science Based Medicine (SBM) Website. SBM is a long-running blog, founded by Dr Steve Novella a clinical neurologist, and co-edited by Dr David Gorski, a surgical oncologist. The blog aims to present medical information based on the principles of science and was founded explicitly to combat pseudoscience. If ever a science based approach was needed, it’s for this topic.

To that end, SBM recently published a review of a book, Irreversible Damage by Abigail Shrier that questions the current practice of prescribing hormone-blockers to trans-identifying children. The book makes the case that a new phenomenon is spreading rapidly — of teenage girls suddenly identifying as trans despite no previous history of gender discomfort.

Shrier believes this is a social craze, spread by peer influence and turbo-charged by social media. It’s not unusual for girls going through puberty to feel unhappy with their bodies and to have a desperate need to carve out their own identities. What concerns Shrier is that girls who identify as trans are now placed onto a pathway of medical treatment, starting with hormone-blockers that delay puberty, that leads almost inexorably to further hormone treatment and even surgery with irreversible consequences including breast removal, lifelong infertility and the possibility of terrible regret.

Is Shrier right? The short answer is we don’t know. There’s a terrifying paucity of good quality science in this area. We don’t even have the most basic data such as how many boys and girls identify as trans or how the incidence is changing. The SBM review concluded that Shrier’s book raised legitimate grounds for concern whilst the lack of good scientific studies makes firm conclusions impossible. That nuanced article didn’t last long. Within days SBM had removed the article, apparently because it was “below the minimal acceptable standard”. This is the only article on SBM ever to have been retracted, a particularly astonishing decision since it was written not by some one-off contributor, but by Dr Harriet Hall, one of the site’s 3 editors (along with Novella and Gorski) who has written over 700 articles for the blog.

Clearly something extraordinary is going on; either a highly experienced doctor and blogger has written something so egregious it — uniquely for SBM — had to be retracted, or Novella and Gorski (N&G) removed a perfectly good article for ideological reasons. You can read the withdrawn review republished here to make up your own mind. 

An explanation, of sorts, appeared a few days later with the publication of a piece written by N&G themselves which summarises the Shrier book and the evidence surrounding it. Almost as soon as it was published, the suspicion was raised that N&G had written their article without actually having read the book, so thin was their understanding of the book’s contents. They’ve since confirmed to me via email that they had not in fact finished reading the book at the time but said that “David has read the introduction and first couple of chapters” (how much if any Steve Novella has read is unstated). Their justification is that they were critiquing Hall’s review — not the book itself. But a brief read of their article shows this to be disingenuous. Indeed they conclude that the book’s central claim “is not supported by any evidence and is cobbled together with a gross misreading of the scientific evidence.” It’s hard to see how you could justify reaching such a conclusion without the basic courtesy of reading the book you criticise. Rather they seem to have come to a view without even having to open the book, telling me “the title of the book in and of itself is very inflammatory”.

It’s hard to see how you could justify reaching such a conclusion without the basic courtesy of reading the book

Their article goes on to examine the evidence relating to the claims in Shrier’s book and was followed by several further blogs written by guest writers all of which reach a similar conclusion — that Shrier is entirely wrong. There’s nothing wrong in publishing opinion pieces offering a different perspective from Hall’s review but — as so often when it comes to the trans issue — only one side of the issue is allowed. Worse, these almost unreadable pieces are riddled with errors, misrepresentations and half-truths, giving the lie to the notion that the only thing wrong with Hall’s article was its accuracy. Hats off to the writers who have documented in excruciating detail the many problems with these articles:

How Science-Based Medicine botched its coverage of the youth gender medicine debate

Irreversible Reputational Damage

Science-Based Medicine’s Coverage of ‘Irreversible Damage’

The Decline and Fall of Science-Based Medicine

A comment on Science-Based Medicine’s ‘The Science of Transgender Treatment’

This Twitter thread 

Since it would take volumes to detail all the problems, I’m going to concentrate just on the article by N&G and on one specific question: are hormone and hormone-blocking treatments effective for the teenage girls described in Abigail Shrier’s book?

Firstly N&G describe puberty-suppressing hormones as fully reversible (no evidence provided). And yet the NHS information page states “Little is known about the long-term side effects of hormone or puberty blockers in children with gender dysphoria … It’s also not known whether hormone blockers affect the development of the teenage brain or children’s bones.” The WPATH guidelines specifically linked to in the N&G article state “there are concerns about negative physical side effects of GnRH analogue use” (for instance, on bone development and height) and in particular that there are “adolescents who will never develop reproductive function in their natal sex due to blockers or cross-gender hormones. At this time there is no technique for preserving function from the gonads of these individuals.” At best it’s questionable how reversible hormone-blockers are, but N&G seem happy to disregard any uncertainty on the issue.

The crucial question a blog like SBM should be asking is “do hormone altering treatments work for transgender children and adolescents”? You might expect their article, titled as it is “The Science of Transgender Treatment”, to be packed full of scientific evidence. Yet only two studies on this topic are linked to. The first is a 2020 study which G&N say found that hormonal therapy in trans teens decreased suicidal ideation. In fact the study found no statistically significant improvement for female-to-male youths (the demographic relevant to Shrier’s book) in any measure. Nor do they find any significant difference in suicidal ideation in any group. But it gets worse. This was a longitudinal study with no control group — so even if there had been a difference it would be impossible to say it was due to the treatment. Imagine if a homeopath had shown that in a group of people with flu, all given homeopathic remedies, some of them had improved with time. Novella and Gorski would rightly have considered this evidence worthless.

The other quoted study  is even less convincing: a survey asking transgender adults to self report the treatments they received as teenagers. Such studies are prone to so many sources of error and bias that they could only be considered the very weakest form of evidence and certainly not sufficient to reach any conclusions on effectiveness. Normally the hallmark of a science-based approach is that any quoted study is properly placed in context with a clear assessment of the strength of evidence provided. Yet N&G quote these two studies with not a single mention of their very great weaknesses.

The brutal truth is we have no good-quality scientific data on how best to treat children with gender dysphoria

N&G cryptically say “there are more studies” (no citations given) but one would presume they have chosen the 2 most convincing examples. And yet N&G go on to conclude “there is copious evidence supporting the conclusion that the benefits of gender affirming interventions outweigh the risks”. I think I’ve shown that the evidence gets nowhere near that level of certainty. But you don’t need to take my word for it. You can read the assessment of NICE (the UK’s highly regarded National Institute of Health and Care Excellence) which concludes that the outcomes from hormone blockers are of “questionable clinical value”, and that “the studies themselves are not reliable and changes could be due to confounding, bias or chance.” A review of post-puberty hormone treatment reached similar conclusions.

Or read the review from the BMJ Evidence Based Medicine Blog, which concludes: “There are significant problems with how the evidence for Gender-affirming cross-sex hormone has been collected and analysed that prevents definitive conclusions to be drawn” and wonders whether the use of such drugs is justified given they “can cause substantial harms and even death”. Such comprehensive reviews from respected sources would normally be prize nuggets for a science based blog. Why N&G fail to even mention them is left for the reader to ponder.

The brutal truth is we have virtually no good-quality scientific data on how best to treat children and adolescents with gender dysphoria — and know even less about the sorts of cases described in Shrier’s book. This is scarcely surprising given the deeply toxic nature of this topic, where any scientist who presents the “wrong” results faces bullying, censorship or worse. That leaves parents and medical professionals in a deeply unhappy situation; having to make life-changing decisions with scarcely any data. But as one blogger put it when Lupron, one of the drugs now used to treat trans children, was proposed as a cure for autism: “If you’re going to give a potent drug like Lupron to children, a drug that can almost completely shut down the synthesis of both male and female steroid hormones, you’d better have damned good evidence that it’s likely to help to make it worth the risk.” The blogger? Dr David Gorski on a site called Science Based Medicine. That, at least, is something Gorski and I can agree on.