Teenagers using social media for more than three hours a day are more likely to go to bed after 23:00 and wake during the night, UK research suggests.
This affects one in three teens – with one in five spending five hours or more on apps like Instagram, WhatsApp and Facebook every day, the study said.
The University of Glasgow researchers said 13 to 15 year-olds may be delaying bedtime by being on their phones.
Psychiatrists say screens should be avoided in the hour before bed.
But the study, of 12,000 teenagers, recognised that getting them off their phones could be “especially challenging” because it was a time of growing independence, when keeping in touch with friends was important.
Teenagers who were very high social-media users (five hours or