For several days this week the veteran Swedish journalist Malou von Sivers will cover the same topic in every episode of her nightly TV chat show: the extraordinary rise in diagnoses of gender dysphoria among teenage girls.

Lukas Romson, an equality consultant and one of the country’s leading trans activists, is prepared for the worst. “There will be no serious trans activists in the show, because none of us trusts Malou at all,” he says. “I’m afraid she’ll just use us.”

But the fact that a mainstream programme is devoting so much time to the issue demonstrates just how much the debate has shifted in Sweden over the past year. “It’s been a very big change and very sudden,” Romson adds. “Everyone – but especially young people – feels worse because of what they perceive as the media’s hatred of them.”

The immediate trigger for Von Sivers’s themed week is a report from Sweden’s Board of Health and Welfare which confirmed a 1,500% rise between 2008 and 2018 in gender dysphoria diagnoses among 13- to 17-year-olds born as girls.

But it also reflects a rapid change in public opinion. Just a year ago, there seemed few official obstacles left in the way of young people who wanted gender reassignment treatment.

In the autumn of 2018, the Social Democrat-led government, under pressure from the gay, lesbian and transgender group RFSL, proposed a new law which would reduce the minimum age for sex reassignment medical care from 18 to 15, remove all need for parental consent, and allow children as young as 12 to change their legal gender.

Then in March last year, the backlash started. Christopher Gillberg, a psychiatrist at Gothenburg’s Sahlgrenska Academy, wrote an article in the Svenska Dagbladet newspaper warning that hormone treatment and surgery on children was “a big experiment” which risked becoming one of the country’s worst medical scandals.

In April, Uppdrag Granskning, an investigative TV programme, followed up with a documentary profiling a former trans man, Sametti, who regretted her irreversible treatment.

In October, the programme turned its fire on the team at Stockholm’s Karolinska University hospital, which specialises in treating minors with gender dysphoria. The unit has been criticised for carrying out double mastectomies on children as young as 14, and accused of rushing through treatment and failing to consider adequately whether patients’ other psychiatric or developmental issues might better explain their unhappiness with their bodies. The Karolinska disputed the claim, saying it carefully assessed each case.

At the same time, Filter magazine profiled the case of Jennifer Ring, a 32-year-old trans woman who hanged herself four years after her surgery. An expert on psychosis who was shown her medical journal by her father, Avi Ring, was quoted as saying that she had shown clear signs of psychosis at the time she first sought treatment for gender dysphoria.

Indeed, the first clinic she approached refused to treat her, citing signs of schizotypal symptoms and lack of a history of gender dysphoria. But the team at Karolinska went ahead. “Karolinska don’t stop anyone; virtually 100% get sex reassignment,” says Ring.

Sweden’s authorities are starting to respond. Shortly before the bill that would have lowered the sex reassignment minimum age was due to be debated in parliament in September, it was shelved, and the Board of Health and Welfare was ordered to reassess the evidence. Its report is due on 31 March.

Sametti, a former trans man who now identifies as a woman, regretted the treatment. Photograph: SVT

After being interviewed on Uppdrag Granskning, Sweden’s health minister, Lena Hallengren, asked the programme to include a text addendum to remind viewers that it had been her predecessor, and not her, who had drafted the controversial law.

On 20 December, the Swedish Agency for Health Technology Assessment, which the government had asked to review the scientific research into the recent surge in teenagers reporting gender dysphoria, reported that there was very little research either into the reason for the increase or the risks or benefits of hormone treatment and surgery.

For Romson this is a worrying turn of events. He blames Gender Identity Challenge Scandinavia (Genid), a parents’ group set up by Ring, a retired professor of neurophysiology, the Swedish toxicologist Karin Svens and the Norwegian teacher Marit Rønstad, for the change in the debate, contrasting these “so-called concerned parents”, some of whom he points out have adult transgender children who should be allowed to speak and decide for themselves, with “real parents” who affirm their children’s chosen identities. Svens was the only Swedish parent to speak openly on Uppdrag Granskning about how her trans son announced he was a boy when he was 17, started going to Karolinska’s adult clinic when he turned 18, and now identifies as male. When asked about Jennifer Ring, he says that friends of hers have told him she found it difficult that her family were unwilling to accept her as a trans woman.

“When I started questioning this some years ago, I thought I was alone,” says Svens. “They tried to scare me by repeatedly implying that there is a high risk of suicide, especially if the parents don’t agree. Now more and more parents have found the courage to question what the doctors say.”

The recent report from the Board of Health and Welfare also found that 32.4 percent of 13 to 17-year-olds with gender dysphoria registered at birth as women also had diagnoses for anxiety disorder, 28.9 percent had depression, 19.4 percent had ADHD, and 15.2 percent had autism.

Trans people often explain the higher levels of depression and anxiety by pointing to the difficult experience living in a body that clashes with their gender identity, particularly when many in society, often including parents and friends, do not accept their identity.

One of the most surprising changes has been the growing divisions between trans activists. While Romson warns that children will have even more anxiety because of the change in the debate, Aleksa Lundberg, a trans woman and longstanding activist, is backing the call for more research.

Last October she apologised for not having been sufficiently open about the depression she had felt after her operation. “I would probably not undergo corrective surgery if I had the same choice today,” she wrote. “And I want to apologise to those who perhaps needed to hear that story earlier.”

• This article was amended on 27 February 2020 to clarify that when Lukas Romson referred to “so-called concerned parents” he was noting that some have adult transgender children who should be able to choose their own gender identities. Romson’s job title has also been included.