Social media raises children’s risk of mental health problems by up to half, a major study suggests.

Social media use exposes teenagers to cyber-bullying, harms sleep and stops them exercising, the researchers warn.

Checking Facebook, Instagram and Snapchat weekly mean the risk of suffering “psychological distress” is up to 20 percent.

Logging in as little as four times a day can raise the danger by half again, the study of more than 10,000 children shows.

Teenage girls who check Facebook, Instagram and Snapchat weekly have a 20 percent risk of psychological distress, it shows.

But for those logging on frequently — four times a day or more — the risk increases to 28 percent, a rise of 40 percent.

Boys on social media irregularly have a ten percent risk of suffering mental health issues.

But it rose to 15 percent in those who logged on several times a day — a jump of a half.

'PSYCHOLOGICAL DISTRESS'

The findings come from the first major study look at how heavy social media use may damage mental health. It involved more than 10,000 English youngsters aged 13 to 16.

They say parents should not be endlessly telling children to get off their phones and tablets.

Instead, they should ensure children get eight to ten hours’ sleep and insist they exercise.

Lead researcher Professor Russell Viner, from University College London, said: “While we obsess a lot about social media, how much do we obsess about how much our young people sleep? Not very much.”

But with half of all mental illness starting before the age of 14, Dr Louise Theodosiou, from the Royal College of Psychiatrists, said social media giants must do more to protect kids.

She said: “We’ve seen a worrying rise in low mood and depression among girls and young women in recent years.

“This paper helps our understanding of the link between social media use and mental health problems.”

The findings are in The Lancet Child & Adolescent Health.