The Gender Identity Development Service (GIDS) based at the Tavistock and Portman Trust in North London, was set up initially to provide – for most part-taking therapies to young people who were questioning their gender identity. In the last decade GIDS has referred more than thousand children, some as young as nine years old, for medication to block their puberty and then cross-sex hormones, which cause irreversible changes to the body. While some young people thrive after taking the blocker, many seemed to become worse. As the number of young people seeking GIDS’s advice exploded, increasing twenty-five-fold, the profile of patients changed from largely pre-pubescent boys to mostly adolescent girls, who were often contending with other difficulties.

This is a classic example of how a well-meaning institution can go awry. Established in 1989 as the UK’s pioneering clinic in its field, is now set to close this spring after having prescribed puberty blockers to under 16, who were questioning their gender identity.

Barnes a BBC journalist whose reporting for the Newsnight triggered an investigation into the Tavistock by the NHS regulator, has studied scientific studies and freedom of Information requests, interviewed 60 clinicians to bring out this book.

 The clinic took nuanced approach to distressed teenagers, using therapy to work out how best to help them. But the puberty blockers, which were in turn the gateway to cross-sex harmones , and drastic irreversible surgery.

In 2007, the clinic was seeing about 50 children a year and by the time its closure was announced in 2022, it was getting over thousand referrals every year.

Time to Think, reveals how shockingly little evidence there was for what worked- the studies cited were based on tiny samples – and there was little on interest in collecting more data.  This lack of interest seems to betray a willful failure to safeguard the wellbeing of Children involved.

Not all children thrived on blockers, as many saw their mental health deteriorate and several who sought help were suffering from multiple problems including autism. The number of prepubescent boys was overtaken by the number of girls, many of them self-harming or suffering from eating disorders. By attending the unit, girls were on irreversible pathway  such as top surgery – a phrase for the cutting off of female breasts.

In 2005, Tavistock concerns led the medical director David Taylor, to write a repot  but this was not shown to staff or the public until 2020. In 2018, ten worried clinicians took their worries to David Bell, a senior psychoanalyst, who concluded  in a 54-page report which branded the clinic “not fit for purpose”. In 2020, a court case brought by Keira Bell, who accused the clinic of having treated her “like an experiment” and rushing her into making irreversible changes to her body.

It was not until 2022 that NHS England took the decision to close the clinic, after another report from Hilary Cass,  after Paul Jenkins and Paul Burstow, the CEO and chair of the Trust have both stepped down.

Many children were subjected to treatment that has permanently changed their bodies without proper evidence, as the gender identity clinic became a money-spinner for the Tavistock Trust.

Time to Think: The Inside Story of the Collapse of Tavistock’s Gender Service for Children by Hannah Barnes, Swift Press £20, 288 pages.