But research from the University of Glasgow this week found that teenagers are waking up in the night purely to check for new tweets and messages on social media, and this is turning them into classroom zombies. Many are averaging just five hours of disjointed sleep a night, and the pressure to be online constantly is leading to an anxiety epidemic, according to the study.

And, with further bad news for phone-obsessives, child health specialist Dr Aric Sigman, a fellow of Britain's Royal Society of Medicine, has weighed in, pointing out that parents are often to blame for their children's phone habits, as they sit scrolling during dinner, Instagramming through family holidays, and tweeting instead of talking. 

He recommends that two hours of screen-time a day is more than enough for teenagers, and he's right, of course. But while I agree that it's bad for their mental health, and sensible adults should be whisking phones from hands in one fluid movement, I'd be a hypocrite to try to get between my (22-year-old) son and his tablet, because I'm just as bad.

I have been addicted to my phone since the first iPhone appeared. Of course, for my job as a journalist, I need to keep it with me, to check email, research facts and make phone calls. It's by my side wherever I go, and I depend on it to satiate my fear of missing out (FoMo) on interesting things. Call it PhoMo, if you will.

Over time, it has got to the point where, if I'm "off-grid", I feel the way I did when I was off school, ill – as though all the exciting stuff is happening without me. But now I'm desperate not to miss breaking news, a tweet that's gone viral, or a message from my boyfriend, son or friend that I can't answer – because I'm not there, ready and waiting. 

"But what does it matter?" ask the smug sleepers who remain impervious to the siren lure of social media, who can "take it or leave it" and "don't really see the point". Who cares if you read a timely joke or reply to a friend at 3am or 10am? To which I say, I care, because I want to watch the world as it unfolds and be a part of it, not show up at the back of the hall late, when all the best seats have been taken.

Social media is fascinating, like a gripping novel that never ends. When I was a child, I would stay up past midnight reading, because I couldn't bear not knowing what happened next, even though it meant spending the next day limp and whey-faced. Now it's possible to do the same in real time, and there's no one to come in and switch the light off.

But there's a difference between my early hours phone addiction and that of a teenager. Mine is down to my fear of missing out on interesting things, but I suspect that a teenager's worry is about self-protection, a constant urge to check they're not being assessed on social media and found wanting.

I've never had to deal with bullying in cyberspace, or sexting, or a mistimed tweet being mocked. I haven't had to risk public shaming on Facebook, or a picture of my training bra going viral. And I never felt, as a teenager, that everyone's life was better than mine. I didn't know if it was or not. We didn't discuss it.

It must be both demoralising and exhausting for today's teens. And while I can catch up on my sleep at the weekend, sadly, the kind of mental exhaustion and social media angst they face isn't as easily overcome.