'Six factors apparently explain 80 per cent of the variation in happiness... Not all of these can be tackled by a typical primary care trust.'

In 1998 the King of Bhutan declared his country would begin measuring its progress in terms of gross national happiness. Should the NHS follow suit?

This may seem a strange question, given all that is going on. But a new book, Happiness - lessons from a new science, by Professor Richard Layard of the London School of Economics, prompts questions about how the NHS could better contribute to our national well-being.

Professor Layard argues that happiness is measurable (by asking people and by PET scans of the left frontal lobe). He notes that on average happiness has not risen in Britain since 1975 despite rising incomes; yet he says there are concrete ways of boosting happiness, and increasing it should be a public goal.

Six factors apparently explain 80 per cent of the variation in happiness, and 57 per cent of the difference in suicide rates between countries. They are the unemployment rate, the divorce rate, level of trust, quality of government, membership of community organisations, and the proportion who believe in God.

Not all of these can be tackled by a typical primary care trust. In fact the Pope would struggle.

But if so inclined, the NHS could play its part. While health does not come top of the determinants of happiness, it clearly matters. Health contributes to happiness, and there is some evidence that improving happiness improves healthy life expectancy. However, in valuing future health states, Professor Layard points out that healthy members of the public tend to underestimate the ability of people with many medical conditions to adapt to their new circumstances. The exceptions to this are chronic pain and some mental illnesses - in other words 'feelings that come from inside themselves rather than limitations on their external activities'.

Now I'm not suggesting the 'pursuit of happiness' should become the new rallying cry for NHS reform. But from time to time it's good to think about the broader mission of the NHS as a mild corrective to the immediate preoccupations that fill most of our working days.

So for PCTs and trusts reckless/far-sighted enough (delete as applicable) to want to play their part in improving the happiness of their local communities, here is a provisional seven-point plan.

First, improve mental health services, and increase the share of local NHS spending on mental health. Mental illness and addiction cause nearly half of all disability, and in any one year perhaps a fifth of us have a serious mental health problem. But under half of people with major depression are treated effectively - despite the fact that depression explains more of the variation in happiness than do income differentials, after accounting for the link between poverty and depression. The result, as Professor Layard puts it, is that 'mental illness is the greatest source of misery in the West'.

Second, expand the availability of NHS treatment for people with drug and alcohol addictions. This is not only the right thing to do for the individuals and their families. It produces massive positive knock-ons for local communities in terms of reduced crime and re-offending.

Third, take pain seriously. Multidisciplinary pain-management services are typically under-invested in. And most hospitals have been far too slow to roll out patient controlled analgesia so that every inpatient who could benefit gets it. Reducing avoidable misery will increase net happiness.

Fourth, help cut unemployment through more active clinical support to get people off incapacity benefit.

Fifth, become more evidence-based about the deployment of community nursing and child psychology resources to support children's development and the 'production of future citizens'- for example through Sure Start and school-based programmes.

Sixth, get more sophisticated about understanding what influences staff happiness. The good news is that a sense of professional purpose and vocation improves happiness, and many health professionals have it. Recent moves to make NHS employment more family friendly will also apparently help. But recent pay rises apparently won't. This is because research shows that as incomes rise, the norm by which they are judged increases too. So it is estimated that 40 per cent of a pay rise is forgotten a year later.

People care more about their relative income judged against a subjective comparator group. Which helps explain why East Germans' happiness declined after reunification even though incomes rose, because they started comparing themselves with the West Germans rather than the Soviet Bloc. Perhaps we now need that effect in reverse, with doctors here being reminded they are now the best paid in Europe - and that it was 20,000 German doctors who two weeks ago were striking for pay as good as that on offer in the NHS.

Seventh, strengthen the ties of NHS institutions to the communities they serve, and in turn help strengthen the bonds of community. For example, foundation trusts now have more members than do all the national political parties put together. But the challenge is to deliver on the potential that membership represents.

Underpinning all this, remember that the NHS is a psychological compact with the British people. The NHS produces not just healthcare but reassurance: reassurance that care will be available when you and your family need it. That in turn requires the NHS in all it does to embody the attributes of timeliness, reliability, compassion, and respect. Which is how the happiness agenda and the NHS reform agenda might perhaps converge.

PS The King of Bhutan has since announced he is abdicating to pursue happiness with his four wives.

Simon Stevens is president of UnitedHealth Europe and the prime minister's former health adviser.