‘Wherever I look these days, somebody somewhere is talking about trans issues,” said psychotherapist and author Stella O’Malley at the start of Trans Kids: It’s Time to Talk (Channel 4). It certainly feels that way. The figures are astonishing: in the last nine years, the number of children referred to the NHS’s gender service has gone up by 2,500 per cent. Trans vloggers have become YouTube stars with merchandise ranges and “chest-binding for beginners” videos that attract hundreds of thousands of views.

O’Malley set out to examine whether allowing young people to change gender is doing them harm. She does not come from a position of neutrality. As a child growing up in Eighties Dublin, O’Malley was convinced that she was a boy, trapped in a girl’s body. Yet now, aged 43, she is a mother-of-two (married to a man) and entirely happy with being a woman. In other words: it was just a phase.

She is worried that impressionable teenagers “are being sold a pup”, rushing headlong into the transitioning process without understanding the implications. “I’m haunted by the thought there are kids out there like I was – kids that change their minds,” O’Malley said. “If I had been a child today I’m absolutely certain that I would have transitioned. And where would that have left me?”