Apologies for coming on like a nosy Freudian, but how would you describe your childhood? A symphony of fun? A collection of balmy days spent happily learning your times tables before playing with your friends in lush cornfields, then home to watch your favourite cartoons and be tucked up in bed by your ever-so-calm, kind and unstressed mother or father? A time when you felt happy, confident and secure - so coddled and cared for that not so much as a feather's weight ever descended upon your narrow shoulders?

Yeah, me neither. I was thinking recently about a pact I made with myself, aged ten, when I was expecting to go to the local Essex comprehensive (a vast monolith recently formed by the merger of three local schools). Up until then, I had got through a messy childhood of premature death and social workers by reading a lot. But I was convinced, on the evidence culled from my primary-school experience, that if I continued to express an interest in books, I was in for trouble. "I can either keep reading," I decided, "and face being beaten up, or I can pretend to be someone else entirely, someone sort of hard and cool, and - well, not be beaten up." The second of these would have been a huge stretch, but it was easily the preferable option.

My pact never came to fruition, as I was sent off to a charity-run boarding school, which had its own occasional problems (I once woke up to find one of the other girls holding a large knife to my throat), but where you could certainly read with impunity. My autistic younger brother, Frazer, was sent to the comprehensive (there weren't any appropriate specialist schools in the area), where the learning support team did their best to look after him but where, none the less, one of his peers throttled him with a T-shirt.

I guess childhood really is idyllic for some people, but not for many of us. At the very least, it's a time of huge change when you are powerless over most of the important decisions - where you live, whom you live with, which school you go to - and when you're forced to deal with that most difficult of all groups: your direct peers, most of whom are feeling just as powerless and worried and insecure as you do.

It is, in short, a brutal time, and for British kids it appears to have become even more brutal. A Unicef report published on 14 February placed the UK bottom of 21 economically advanced nations when it comes to childhood well-being, perhaps its most depressing finding being that only 43 per cent of young people find their peers "kind and helpful". At the same time as it appeared, in the space of 11 days, three teenaged boys were shot and killed in London.

Then the following weekend, there came the report that, recently, children as young as 12 had been diagnosed as alcoholics. I'm all for experimentation and risk-taking, but when teenagers are being diagnosed with cirrhosis of the liver, that suggests they haven't just been stealing a few swigs from their parents' drinks cabinets for a laugh: they've been drinking for some other, entirely more complex reasons.

What seems particularly ironic, is that, as a society, we have never idealised our teenage years more. Just as our kids are facing childhoods that are more brutal than ever, at least on the face of it, the rest of us are becoming steeped in nostalgia. Fortysomethings sign up to Friends Reunited to meet up with the girl they loved at school; thirtysomethings buy up Star Wars action figures; twentysomethings buy cartoon paraphernalia. We all buy clothes at Topshop - 50-year-olds alongside 16-year-olds. We all listen to our iPods. We all have at least one pair of jeans and trainers in our wardrobe.

There's nothing wrong with this, except that I wonder how the collapse of the generation gap affects teenagers. For many of them, the constant refrain that these are the best years of their lives must leave them feeling: a) terrified (what, it doesn't get any better than this?); b) depressed (see a); and c) dismissed. How can you communicate your fear and loathing if everyone around you is adamant that being a teenager is completely brilliant?

In truth, I would guess, although we may have loved the cartoons we watched as children and may have some fond memories of first crushes, the thing that makes us most nostalgic for our teenage years is that they were a time that pre-dates our fears of our own mortality. Looking back, you can see that that is a powerful feeling, but it's not something you can appreciate until you're older, so it doesn't hold much sway for those in the midst of their own teenage hell.

I don't know what the answer is when it comes to making teenagers' lives better, but allowing them to vote at 16, criminalising them less (are antisocial behaviour orders really helping?), and going much, much further to stamp out bullying would seem to be a start. And surely, in addition to all this, it would be prudent for the rest of us to stop banging on about how fucking fabulous it is to be a teenager.

Kira Cochrane is the women's editor of the Guardian