This is a summary, try and track down the actual document if you can
Baroness Cass has published a parliamentary briefing defending the proposed PATHWAYS puberty-blocker trial.
The briefing accepts several very important points:
- there is currently no robust evidence that puberty blockers are safe or effective for children with gender dysphoria;
- the Dutch and Tavistock studies were methodologically weak;
- the Tavistock study found no overall psychological benefit;
- any hoped-for reduction in distress or improvement in quality of life remains only a hypothesis;
- puberty blockers reduce normal bone-mineral development;
- the long-term effects on adult bone strength, fertility, sexual development and cognition remain unknown.
Cass’s main argument is that a trial is nevertheless necessary because some children are obtaining hormones or other drugs from private or unregulated sources. She says that carefully selected children, fewer than 5% of those attending the new NHS services, would be extensively assessed, approved by a national multidisciplinary panel and closely monitored during the trial.
She argues that blockers might reduce distress, “buy time”, prevent some children from obtaining cross-sex hormones illegally and help researchers establish whether there is any benefit. She concludes that refusing to run the trial is not neutral and claims that more children would be harmed without it.
However, the briefing has some serious weaknesses.
First, it is an argument in favour of the trial, not a neutral account of the evidence. Uncertainty about benefit is used to justify experimenting, while uncertainty about harm is repeatedly presented in reassuring language.
Cass describes around 250 children who admitted taking various medications as “250 cases of known harm”. That is not supported by the information given. Unsafe or unmonitored medication use creates a risk of harm, but it does not prove that every one of those children was actually harmed.
The existence of illegal prescribing also does not demonstrate that giving puberty blockers through an NHS trial is beneficial or necessary. The alternative is not simply to abandon these children. They can still receive psychological support, treatment for mental-health problems, help with school, neurodevelopmental assessment and family support without suppressing puberty.
The claim that PATHWAYS is not intended to lead to cross-sex hormones is also difficult to reconcile with the trial’s selection criteria and the historic evidence. Participants will be selected partly because they have persistent gender dysphoria, a continuing desire to transition and a repeated request for endocrine treatment. In previous cohorts, the overwhelming majority of children placed on blockers went on to cross-sex hormones.
Calling blockers a neutral “pause” or a way of “buying time” is therefore unproven. It is equally possible that suppressing normal puberty prevents the physical and psychological development through which some children would otherwise become reconciled to their sex.
The trial also cannot answer many of the most important questions. The randomised blocker-versus-no-blocker comparison lasts only about 12 months. After that, both groups receive blockers. A study of this size and length cannot determine adult fertility, mature sexual function, peak bone mass, fracture risk, later regret or long-term psychological outcomes.
Cass is right that the existing evidence is extremely poor. But that does not automatically establish that this particular experiment is ethical, necessary or capable of answering the questions that matter most.
The strongest evidence-based conclusion remains that puberty blockers should not be offered as routine treatment for children with gender dysphoria. They suppress a normal developmental process, have a known negative effect on bone development, carry serious unresolved long-term risks and have not been shown reliably to resolve gender dysphoria or produce an overall psychological benefit.