Take a breath. Take a deep, deep breath and feel the air going into your nostrils, and hold your breath and empty your mind, and when your mind is empty count to six. Don’t worry if you’re thinking about your dinner. Just let all thoughts of your dinner go up in a cloud and float away. Now get back to the breath. Feel that breath passing out of your lungs and out of your nostrils, and into the air. And now do it over and over and over and over again.

If this is your idea of a good time, you’ll be pleased to hear about a new study funded by the Wellcome Trust, the biggest of its kind in the world. The study, which will be conducted by psychologists and neuroscientists from Oxford University and University College London, will involve 7,000 teenagers from 76 secondary schools and look at the impact of “mindfulness” on mental health.

The children will, apparently, be taught things like “walking meditations” where they will try to think about the sensations in their body and “7/11” breathing exercises where they breathe in for seven seconds and breathe out for – you’ve guessed it – 11. They will also have to do 20 minutes of “daily practice” at home. Yes, that’s daily as in every single day. And they will have to do this for seven years. Here in Britain, not in North Korea.

It had to happen. Once they started bringing “mindfulness” to Harvard Business School and Google, it was only a question of time. When grownups rush to buy a book called The Mindfulness Colouring Book, and are the ones not just digging out the crayons but actually colouring it in, it only seems fair to give the kids a go. Who wouldn’t want to give the kids a go? Let’s just hope they enjoy it an awful lot more than me.

I was first taught “mindfulness” in a hut in a village in Cambodia, by a smiley, wizened old monk. The main thing I remember, as I sat cross-legged on a very hard cushion, and tried not to think about the pain in my hips, was fighting the urge to scream. Then there was the chi gong instructor on the holistic holiday on Skyros. Then there was the hairy American at the Thai spa I thought might be a cult. By then, I was used to searching for my “inner smile”. But I drew the line at laughing on demand while flexing the muscles in my pelvic floor.

OK, so you have to practise. I know you have to practise. That’s why I’ve sent away for piles of CDs so I can practise being “mindful” without having to find space in my flat for a Buddhist monk. The trouble is, the voices. The boring, droning voices. The trouble is the grammar. “Breathing,” says the voice. “Sitting quietly,” says the voice. Which makes me want to yell that you can’t use the present participle to give a command. Which makes me, in fact, even crosser than I was before.

When I was seriously ill, I read books that told me what to do. I should, they said, start the day with meditation. I should give up sugar and cheese and gluten and wine.

For a while, I did it all. I set my alarm and sat on a cushion and tried to empty all thoughts of my gluten-free breakfast while holding and counting my breath. For the months I did it, I was pale and pinched. When I swapped the meditation for a bit of extra kip and a couple of glasses of sauvignon when I got home, life looked up.

I don’t doubt that “mindfulness” can cut stress, and make your brain work better. Lots of things can cut stress and make your brain work better. Knitting, for example, and walking, and kissing, and baking, and writing poems, and picking flowers and chasing butterflies, and playing football, and stroking pets. Oh, and sex. Lots of lovely sex. But you can see why the Wellcome Trust wouldn’t want to fund 7,000 teenagers to have daily sex.

Meditation has been around for at least 2,000 years. It hasn’t yet changed the world, but I suppose one day it might. What it has done, in the last few years at least, is ride the crest of a wave we call fashion. It has been rebranded. It has got itself a new name. It has even been brought in to solve problems at banks. And it has made a lot of money. “Mindfulness” makes an awful lot of money. Perhaps what those children will learn is about marketing and money. But mental health? Don’t hold your breath.