Children who spend more than three hours a day on social media websites are twice as likely to suffer mental health issues, British data suggests.
A report from Britain's Office for National Statistics found higher levels of emotional problems, issues with other children, hyperactivity and poor behaviour among youngsters who spent a lot of time on social media websites.
Social media sites that are popular with young people include Facebook, Twitter, Instagram, Pinterest and Snapchat.
The report found that between 2012 and 2013, 37 per cent of children spent no time on social networking websites while 56 per cent spent up to three hours.
Around 8 per cent of children spent over three hours on social networking websites on a typical school day.
Girls were far more likely than boys to spend over three hours on social networking websites. In 2012 to 2013, around one in 10 girls (11 per cent) spent over three hours on social networking websites compared with just 5 per cent of boys.
The report found a "clear association" between longer time on social websites and children reporting difficulties that suggest mental health problems.
Those children who spent more than three hours on social websites on a normal school day reported "significantly higher total difficulties scores" than either those who did not use social websites or who spent less time on them.
The report said: "Of those children who spent more than three hours on a social website on a normal school day, around 27 per cent reported high or very high total difficulties scores.
"This is more than double the proportion of those children spending no time on social websites on a normal school day (12 per cent) and the proportion spending up to 3 hours a day on a social website (11 per cent)."
The report said social media websites are "ever-present features of social life, especially for the young."
But it added: "While they may provide an additional way to connect with others and form relationships and thus increase children's mental health, they could also be a source of social comparison, cyber bullying and isolation, reducing children's mental health."
Other research has shown a link between screen time (including watching television, DVDs and videos) and higher levels of emotional distress, anxiety and depression.
