Over three hours a day on social media doubles a teenager's risk of depression and anxiety symptoms
It isn't the phone itself. It's the hours, the time of night, and what those hours replace.

A study that followed more than 6,500 American teenagers over several years, published in JAMA Psychiatry in 2019, found that those who spent more than three hours a day on social media had about twice the risk of later reporting problems such as depression, anxiety and loneliness, compared with those who didn't use it. The more hours, the higher the risk.
Many teenagers here now spend well over three hours a day on reels, chats and games, and a good part of it happens late at night.
Researchers think a few things are going on. Endless comparison with other people's filtered lives. Online bullying, which follows a child home in a way the school playground never could. And, perhaps most of all, what gets pushed out: every hour on the phone is an hour not spent sleeping, moving or being with people face to face. The phone in bed at 1 in the morning probably does more harm than the phone at 5 in the evening.

