Video report by ITV News National Editor Allegra Stratton
The chief medical officer for England has accused social media companies of putting "profit before children".
Professor Dame Sally Davies' comments come as she, along with the UK's other top doctors, issued a number of recommendations to address concerns over how social media is affecting young people's mental health.
Dame Sally said it was time for social media companies to start self-regulating content, and, if they failed to take control, for the government to introduce tighter legislation.
She told ITV News: "They have put profit before children. I believe that they need to start now, voluntarily, sorting this out and if they don't sort it, it's clear government, on behalf of the people, will have to take action."
The advice from the UK's chief medical officers forms part of a “precautionary approach” by officials, following an independent review on the effect of screen and social media use in children and young people.
It is particularly resonant for the mother of 16-year-old Lani Clarke who took her own life on 7 February 2018.
After her death, her mother Bonnie Mellor discovered she had logged into a suicide chatroom and looked at self harm images online.
Ms Mellor told ITV News that she "wasn't aware that that stuff was available and existed online".
She said: "She was already struggling. I think it could only have helped compound those feelings and emotions she had.
"And when you're constantly bombarded by a stream of damaging, harmful images and the language that's used online, that can only have helped her on her downward spiral.
"We had no idea she was struggling with her mental health and to see the kind of stuff she was looking at, is just incredibly worrying as a parent."
The guidance published by the chief medical officers
- Families should ban phones at bedtime
- Keep phones away from the dinner table and give children full attention
- Parents that they should never assume a child is happy to have their photo published online
- Taking regular screen breaks
Ms Mellor said that social media giants and the government must shoulder the blame.
"Both the tech companies and the government need to take a share of the responsibility," she told ITV News.
"The government has a duty to help protect our children and they need to put these laws in place. And the tech companies have a duty of care to their users."
The guidelines released on Thursday, the first official advice on social media and screen that has been issued, is an attempt by the government to help parents.
The report by the medical officers called for action from technology companies, backing the establishment of an industry duty of care and a voluntary code of conduct.
The report by the medical officers states said: “It is imperative that the technology industry proactively acts in the interests of users, as well as shareholders."
Measures to protect children online could include introducing clearer terms of conditions, improving age verification, and sharing anonymised data for scientific research to help improve understanding of the effect of screen time on young people, they said.
The chief medical officers – Dame Sally, Dr Catherine Calderwood for Scotland, Dr Frank Atherton for Wales and Dr Michael McBride for Northern Ireland - said there is insufficient evidence to recommend an optimal amount to spend online, but suggest parents set boundaries to ensure a healthy balance.
Some research included in the review, which was carried out by a team at University College London, has found a link between those who use screen-based activities more frequently and over longer periods and mental health problems, but it is not possible to determine if screen time can cause these issues.
Parents are also being encouraged to talk about sharing photos and information sensibly online with their children and lead by example when it comes to screen use.
Shirley Cramer, chief executive of the Royal Society of Public Health, said: “Barely a day passes without yet more concerning findings regarding the potential harms around screen use or social media.
“This advice is therefore a step in the right direction towards the establishment of much needed clearer guidance which parents are crying out for to protect their children and help them navigate the Wild West of the digital world.”
What to do if you or someone you know needs help:
If you are in distress or need some support, the Samaritans are available 24 hours a day on 116 123 or through their website.