At the end of May, an intelligent Harvard student stabbed her room-mate 45 times before killing herself. She made international news.

It was a perfect tragedy of high energies and ambitions transformed into violent self-destruction. It was the perfect catalyst for a spate of discussions about everything from the isolation of foreign students to hothouse academic pressures.

Such anxieties seem to have become a regular feature of university life. Every few years a spate of suicides sparks off a predictable series of articles warning of a disturbing new trend.

Yet somehow the trend never quite materialises. Despite the intense pressures of modern student life, the parental expectations, the worries about a tight jobs market, suicide remains a phenomenon for the poor, for those with relatively diminished life chances far more than the glittering prizes of Harvard and Oxford.

ÁñÁ«ÊÓƵ

But it would be wrong to write the Harvard incident off as just another tragic storm in a teacup. There can be little doubt that despite the benefits of prosperity life really does seem to be more stressed than ever before.

Over the last 40 years there have been sharp rises in male suicide right across Europe, and a steady rise in a range of psychosocial disorders, with almost as many problems arising from affluence as from poverty.

ÁñÁ«ÊÓƵ

Many theories have been suggested to explain this. But most boil down to a few common elements. One is choice.

Today's 17-year-old may feel more constrained than a decade ago - certainly in terms of living away from home, or having discretionary spending money. But in other respects the range of choices has continued to escalate. How to organise your sex life; whether to go university; what sort of career to plan for. More relationships at an earlier age - and puberty now starts earlier than ever before - also means more breakups and more heartbreaks.

With so many confusing choices, and few obvious role models, it is not surprising that many find things tough going. At the same time some of the props have fallen away. Young people and adults speak a different language and it is more likely that young people will feel alienated from the dominant culture.

But youth culture is now in secular decline for the simple reason that the size of the youth age cohorts is now so much smaller than in the 1960s. Youth is also more fragmented and less confident, and no longer provides the same feeling of belonging. You may be able to feel miserable along with Nirvana, but you now share almost nothing with the rap fan next door.

ÁñÁ«ÊÓƵ

The problem for young people today is that there are not that many things to belong to. Perhaps a few sports clubs or societies, the Methodists or big campaigns like Greenpeace. But bar the cults, or the fierce loyalty of some football clubs, it is harder to find an attachment.

It would be wrong for universities to try to offer a cloistered security. They cannot wish away the pressures of the outside world. If they can do this for their staff - even Harvard's president recently had to take a leave of absence on grounds of exhaustion - they are hardly likely to be able to do it for their students. And if there are tears to be shed they should probably be for those not lucky enough to share the worries about precisely what career to follow and how to cope with the next round of exams.

Geoff Mulgan is director of Demos, the independent think tank.