Neuropsychologist’s findings on puberty blockers and loss of IQ ‘dismissed’ for gender language and ‘bias’

A neuropsychologist’s warnings about puberty blockers impact on the minds of children raised different red flags about the medical community’s “biases.”

After award-wining University College London professor of clinical neuropsychologist Sallie Baxendale began to investigate the consequences of hormone therapy on the cognitive functions of adolescents, three separate journals determined to reject her paper.

As she explained on Unherd, their determinations were not based on her conclusions, as her paper was merely a summary of the studies that had already been conducted. Instead, as she called for an “urgent” review of findings that showed girls seemingly lost 7 to 15 IQ points while being treated with hormone blockers, Baxendale was criticized for using gendered language.

“They argued that the sex-based terms I had employed to describe the children in the studies — natal sex, male-to-female, female-to-male — indicated a pre-existing sceptisism about the use of blockers,” she wrote. “They suggested that the very presence of these terms would cause people who prescribe these medications to ‘outright dismiss the article,’ and went on to say that by using these terms the paper was ‘preaching to the choir’ and would do a ‘poor job of attracting new members to the fold.'”

The professor continued, “However, the most astonishing response I received was from a reviewer who was concerned that I appeared to be approaching the topic from a ‘bias’ of heavy caution. This reviewer argued that lots of things needed to be sorted out before a clear case for the ‘riskiness’ of puberty blockers could be made, even circumstantially.”

“Indeed,” Baxendale contended, “they appeared to be advocating for a default position of assuming medical treatments are safe, until proven otherwise.”

As it happened, the neuropsychologist had found that of the only 16 studies conducted to examine the impact of gonadotrophin-releasing hormone analogues on cognitive function, 11 had been done exclusively on animals and the remaining conducted on humans were a mixed bag.

Only three looked at the impact giving the medication to children suffering with gender dysphoria had and one of those did not set a baseline before proceeding, she explained. The second did not re-administer their testing and 40% of participants had no outcomes reported.

Ultimately, she determined that only one study, the one that arrived at the concerning figure on IQs dropping, had been done, hence her concern that more studies be done.

As she asked questions like, “What impact does any delay in cognitive development have on an individual’s educational trajectory and subsequent life opportunities given the critical educational window in which these treatments are typically prescribed?” and, “If cognitive development ‘catches up’ following the discontinuation of puberty suppression, how long does this take and is the recovery complete?” she determined the “highly polarised socio-political atmosphere” was likely keeping qualified professionals from conducting their own research in the field.

“None of the reviewers identified any studies that I had missed that demonstrated safe and reversible impacts of puberty blockers on cognitive development, or presented any evidence contrary to my conclusions that the work just hasn’t been done,” wrote Baxendale.

“However, one suggested the evidence may be out there, it just hadn’t been published. They suggested that I trawl through non-peer reviewed conference presentations to look for unpublished studies that might tell a more positive story,” she detailed. “They reviewer appeared to be under the naïve apprehension that studies proving that puberty blockers were safe and effective would have difficulty being published.”

In her own conclusion, Baxendale chided the “safe and reversible” argument of activists peddling pharmaceutical interventions with titles like gender-affirming care as she wrote, “Puberty blockers almost invariably set young people on a course of lifetime medicalisation with high personal, physical and social costs. At present we cannot guarantee that cognitive costs are not added to this burden. Any clinician claiming their treatments are ‘safe and reversible’ without evidence to back it up is failing in their fundamental duty of candour to their patients.”

“Such an approach is unacceptable in any branch of medicine, not least that dealing with highly complex and vulnerable young people,” the neuropsychologist asserted.

Kevin Haggerty


We have no tolerance for comments containing violence, racism, profanity, vulgarity, doxing, or discourteous behavior. If a comment is spam, instead of replying to it please click the ∨ icon below and to the right of that comment. Thank you for partnering with us to maintain fruitful conversation.

Latest Articles