Many parents of digitally obsessed teens must have wished they could bin their smartphones. As evidence mounts about the risks of social media, there is a growing public clamour to protect children better – with some now even calling for a ban.

The debate in the UK took on a fresh resonance in recent days after Esther Ghey, the mother of the murdered teenager Brianna Ghey, added her voice to those highlighting the dangers of smartphones.

“We’d like a law introduced, so that there are mobile phones that are suitable for under-16s,” she told the BBC’s Laura Kuenssberg last Sunday. “So if you’re over 16, you can have an adult phone, but then under the age of 16 you can have a children’s phone, which will not have all of the social media apps that are out there now.”

In demanding tougher curbs on big tech, she echoed other bereaved parents who believe social media played some role in the loss of their children – including Ian Russell, whose daughter Molly took her own life after viewing harmful content online.

Ghey’s intervention came days after social media bosses including the Meta founder Mark Zuckerberg faced a ferocious grilling in the US Senate over their companies’ role in facilitating child sexual exploitation and drug use. He told them: “I’m sorry for everything you’ve been through.”

Some US lawmakers are already going further than castigating the titans of big tech: the conservative state of Florida is debating legislation aimed at banning under-16s from using social media.

In the UK, reports before Christmas suggested Rishi Sunak was considering tougher curbs on social media use by children – though the new Online Safety Act, years in the making and meant to protect children online, is still in the process of being implemented.

A government spokesperson said ministers were focused on the act, but added: “We will always look at ways that children and other internet users can be kept safe online.”

The Tory MP Miriam Cates, the co-chair of the New Conservatives caucus of MPs, recently called for the UK to follow Florida’s lead with a social media ban – warning that “ordinary mums and dads are completely unequipped to do battle with the goliaths of Meta, TikTok and Apple”.

Calls for a crackdown come on the back of a growing body of evidence about the dangers of unfettered social media access.

The US surgeon general, Vivek Murthy, issued an advisory statement last year, warning of “growing evidence that social media use is associated with harm to young people’s mental health”.

He cited a study that showed adolescents who spent more than three hours a day on social media “face double the risk of experiencing poor mental health outcomes, such as symptoms of depression and anxiety”.

Another US academic paper, which mapped the staggered rollout of Facebook across college campuses against data on students’ health, showed that the arrival of the social network coincided with “increased symptoms of poor mental health, especially depression”.

Despite the acknowledged dangers, few experts and campaigners the Guardian spoke to believed an outright ban on social media use by under-16s was workable, or even desirable – though all are united in believing tech firms must do more.

“The people we really want to be taking responsibility for children being safe online are the tech companies,” said Rani Govender, the senior policy officer at the NSPCC.

“We completely recognise why so many parents and families are worried about this, but we think it keeps coming back to: how can we make these apps, these games, these sites, safer by design for children?”

She pointed to the importance of implementing requirements in the Online Safety Act for firms to take a tougher approach to enforcing minimum age limits for creating social media accounts, which are widely flouted.

The media regulator Ofcom is in the process of publishing codes of conduct that will set out in detail firms’ responsibilities on this and other issues.

Lady Beeban Kidron, who campaigns for children’s rights online, said there was understandable focus on removing harmful content from apps – but policymakers should also be focusing on their underlying design.

“What we have to concentrate on is: why are we allowing companies to give addictive products to children? There is no reason on God’s earth that they have to be designed to be addictive. That is a business choice,” she said. “You’ve basically got a faulty product here: they need to fix it.”

That would mean looking under the bonnet of popular apps and rewiring the algorithms blamed for hooking teens – and in some cases, for radicalising them.

Just this week, academic research suggested the video-sharing app TikTok would serve up increasingly misogynistic content to boys who sought content about loneliness, or asked questions about masculinity.

“Algorithmic processes on TikTok and other social media sites target people’s vulnerabilities – such as loneliness or feelings of loss of control – and gamify harmful content,” warned the lead author, Dr Kaitlyn Regehr, who carried out the study in partnership with colleagues at the University of Kent.

A TikTok spokesperson rejected the findings, insisting: “Misogyny has long been prohibited on TikTok and we proactively detect 93% of content we remove for breaking our rules on hate. The methodology used in this report does not reflect how real people experience TikTok.”

Andy Burrows is adviser to the Molly Rose Foundation, set up in Molly Russell’s memory to campaign for change. He warned against the temptation to shut off social media altogether for children who need to learn to navigate the online world.

“The idea of pulling up the drawbridge may seem a superficially attractive and easy solution, but I think it comes with potential unintended consequences, and in particular it risks delaying and perhaps even intensifying the risks that young people will face when they do go online,” he said.

Deana Puccio, a former New York prosecutor, runs workshops in schools to help teens tackle issues such as sexual harassment and negative body image – including coping with the onslaught of social media.

She said the role of parents and schools was crucial. “This is about us all banding together, and the social media companies, and having an interdisciplinary approach to recognising the fact that, yes, our kids are suffering with mental health issues more than ever before – anxiety, depression, body image, self-harm – because of what they’re seeing. There’s no log off time,” she said.

Puccio, the co-founder of The Rap Project with the broadcaster Allison Havey, praised the growing number of schools that now ban smartphone use. But she added: “The problem is, for us to restrict or ban it, all the adults have to be on board – and they’re not. Kids aren’t getting this in a vacuum: we’re giving it to them, as a society.”