Thank God. At last an authoritative voice in the trans so-called debate.

The Cass Review into gender services for young people in England has found that children have been let down by being given medical interventions based on “remarkably weak” clinical evidence.

The review says a lot of other things too, but it’s worth taking a moment to let this key point settle, as it is relevant here in Scotland too. Children were being given puberty blockers and hormone treatments which have poorly understood impacts on things like brain development, without evidence that they even work in easing feelings of gender dysphoria and without knowing the long-term impacts on health and wellbeing.

This isn’t how things are done elsewhere in the NHS. It’s what happens when assumption and belief are allowed to take over from evidence-based medicine.

We knew this was coming. Dr Hillary Cass, a consultant paediatrician, had already published a critical interim report. The Tavistock in London, NHS England’s specialist gender clinic, has already been shut down.

But two additional points will land hard for some people.

One is Dr Cass’s recommendation that children with gender-related distress should, as standard, be screened for mental health problems and forms of neurodiversity like autism. There’s been a huge and sudden increase in numbers seeking help for gender distress in the last 10 years and a great many are young teenaged girls with additional needs or mental health problems. Each patient should be treated holistically, instead of looking at their gender identity in isolation as has tended to happen, says the review. “For most young people, a medical pathway will not be the best way to manage their gender-related distress,” it states.

There should still be the option of giving over-16s hormone treatments but “extreme caution” should be exercised.

This is an important acknowledgment that the distress of a child who feels they are in the wrong gender, won’t necessarily be eased by encouraging them to transition socially and medically. Other underlying issues could be having an impact. They should receive support for all the issues they’re facing, not just their gender distress is isolation.

This may anger some trans activists and disappoint some children who have come to see drug treatment as the only answer, but to others, it will seem like a welcome injection of good sense.

The use of puberty blockers has been ended in England except in clinical research trials but small numbers of children still receive them in Scotland. If that continues in spite of the evidence gaps Dr Cass has highlighted, the Scottish Government and NHS will have to explain why.

Secondly, and crucially, Dr Cass says this: that public discussions of trans-related issues have become so toxic that doctors who favour a cautious, exploratory approach to treating children with gender-related distress, often feel unable to say so for fear of “being called transphobic” or even accused of conducting conversion therapy.

Read more Rebecca McQuillan: The challenge of selling independence in a dangerous world

Read more Rebecca McQuillan: Let’s keep the ScotRail booze ban

Because of this fearfulness, they have been referring children directly to oversubscribed specialist clinics instead of supporting them locally. Those children have then sat on waiting lists for unproven treatments, sometimes for years, without anyone to talk to. Over 1,000 children are currently on the waiting list in Scotland.

That’s quite an indictment. Branding dissenters transphobes has been a highly effective means of shutting down meaningful discussion, in all aspects of the trans debate. People become afraid to speak up against what they see as the orthodoxy – that is the ripple effect of fear. What Dr Cass’s comments do is underline the real-life consequences of this toxic atmosphere for vulnerable children.

Those who deny the validity of trans identities, by the way, make matters worse. Their compassionless jeers only polarise the debate further - concerned moderates don’t want to be mistaken for them, which is another reason they stay quiet.

Calm, reasoned discussion is the best way to help children in gender distress, but what screams out of the pages of this review is how poor quality the evidence is in this field.

We don’t know the long-term consequences of taking puberty blockers and hormones in childhood. We don’t know which children presenting with a trans identity will retain that identity in adulthood. We don’t even know why there’s been such a big increase in the number of young people presenting as trans in the last decade, though the review notes it’s probably a mixture of biological, psychological, social and cultural factors.

But none of it has been helped by people taking up intransigent positions. Dr Cass has said that she is “unbelievably disappointed” that research into 9,000 former patients of the Tavistock gender identity clinic and how they got on in adulthood – research that would have been invaluable – was blocked by adult gender clinics, who refused to help researchers contact the patients. This, she feels, seemed to be “ideologically driven”.

Why would they refuse to help? We can only speculate, but they shouldn’t be surprised if people suspect them of wanting to keep the evidence under wraps.

The Herald: The review sounds a clear warning that vulnerable children need better supportThe review sounds a clear warning that vulnerable children need better support (Image: Newsquest)

Dr Cass is not taking sides; she has tried to follow the evidence. She stresses the dignity of those questioning their gender. She says that people on both sides of the trans debate have “exaggerated or misrepresented” what evidence there is to support their viewpoint.

Parents, children and clinicians with opposing points of view all passionately believe that their approach is the best for children, she acknowledges. There might be evidence that comes to light in future that will require a change of approach.

But she has had to assess the evidence that we have now. And her conclusion is that those entrusted with treating some seriously vulnerable children have been failing to give them the same high standard of care they would receive elsewhere in the NHS.

This is a story of failure and a clear warning that vulnerable children need better support. Parents, children and medical professionals in Scotland will expect the NHS here to take stock too.

And how good it would be if this report helped bring about a shift in tone, where the shouters start taking responsibility for the real-world consequences of trying to shut down sensible debate.