The sense of physical well-being is palpable in the States. If you visit once or twice a year, as I do, you notice the increase of wealth as if through a time-lapse camera. You meet people who don't know what to do with their money; couples who finance their children's expensive university education simply by cashing in a few Microsoft or Coca-Cola shares; and young multi-millionaires who are paid in stock options that rise and rise before their eyes. Property prices are in vertical ascent and there are 12-month waiting lists for a new Porsche, Jaguar or top-of- the-range Mercedes.
They appear never to have had it so good, except that statistics released by the drugs industry seem to indicate that Americans are deeply troubled. Last year spending on drugs that affect the nervous system rose by 17 per cent to $13.4bn, which is about a fifth of the total spent on all drugs. Sales of anti-depressants, which form a significant portion of this figure, were up by nearly a half.
Without labouring the point, it's worth noting that, during this unprecedented boomtime, there are apparently more Americans depressed and/or dissatisfied with life than ever before. It raises an interesting question: does a boom induce outbreaks of psychological disrepair and plain old unhappiness; or is it simply that greater wealth enables people to spend more time seeing their shrinks and imagining themselves to be in the grip of any number of late-20th-century psychological conditions? The answer probably contains elements from both theories, but I favour the latter. I believe it is becoming clear that the increased use of some prescription drugs is a symptom of greater wealth - that it is an economic indicator much like the purchase of winter cruises and four-wheel-drive vehicles.
One more fact to emerge from the figures for legitimate drug sales is that in Japan, which has suffered along with the rest of the Far Eastern economies, the demand for anti-depressants is falling. Sales of drugs such as Prozac and Seroxat/Paxil fell by 2 per cent - at precisely the moment when you might imagine them to rise. Japan and America have vastly different medical cultures, nevertheless the trend in sales in the two countries seems to support the idea that nervous-system drugs might reasonably be partially considered as a luxury item.
We shouldn't find this surprising. After all, the pharmaceutical giants are now putting as much effort into coping with unhappiness, impotence, baldness and obesity as they do into fighting cancer, Aids, heart disease and ulcers. The drugs industry is devoted to improving people's lives and in America that means attending to the problems that are not life- threatening or painful, but which affect a person's happiness and perception of him- or herself. The result is lifestyle drugs, a phrase the industry dislikes because of the suspicion that funds are being diverted from essential research to a frivolous and ultimately misguided attempt to treat the human condition.
We are reaching the state of affairs predicted 60 years ago by Aldous Huxley in Brave New World. Here one of his characters describes Soma, the drug of universal happiness and enhanced performance.
"At sixty our powers and tastes are what they were at seventeen. Old men in the bad old days used to renounce, retire, take to religion, spend their time reading, thinking. Now - such is progress - the old men work, the old men copulate, the old men have no time, no leisure from pleasure."
Huxley might have been describing Viagra, Pfizer's potency drug which has become the fastest-selling prescription drug ever. In the week of its launch two months ago it immediately overtook Lipitor, the cholesterol- reducing pill, and is now recording 700,000 new prescriptions every month. (Lipitor has stabilised at 500,000 new prescriptions.) Pfizer's share price has risen by a third and last week the White House added to the company's good fortune by announcing that Medicaid would pay for Viagra where there was a "medical rationale".
This will undoubtedly please Pfizer, but it won't silence critics who allege that Viagra is being abused by perfectly healthy men in the hope of improving their sexual performance, just as Lipitor is being used by people who want to stay slim without watching their diet.
Pill abuse is inevitable in a society that is so wedded to the concept of an individual's inalienable right to happiness. But we shouldn't get too steamed up at the idea of millions of middle-aged American men suddenly rediscovering the joys of sex - particularly if tests for a female version of Viagra prove successful. Pfizer has been anxious to stress that Viagra is not an aphrodisiac, but is satisfying a genuine medical need. This is not very convincing, especially if you read the numerous sites devoted to Viagra's powers on the internet. Whatever the company's spokesmen say, Viagra a worldwide celebrity among drugs, and its success in America is likely to be repeated in Europe where it is expected to be licensed in three months' time.
We ought to revise our notions about the pharmaceutical industry. Many similar drugs will follow Viagra. There are pills to enhance the memory, which are already being tested on the sufferers of Alzheimer's; pills to prevent pattern baldness, to restore the cell structure of human skin, and to cause instant and refreshing sleep. One day, perhaps soon, happiness, youth and lifelong vigour will come in a single tablet, just like Huxley's Soma.
But as we get used to pharmaceutical enhancement of the quality of our lives, we should remember that in many parts of the world the distress caused by the lack of essential medicine far outweighs the problems of baldness or failing erectile tissue in the West. A series of advertisements appears in the British press pleading for donations to treat eye disease in Africa. A tube of ointment, costing no more than pounds 5, can prevent blindness in a child, and yet there are hundreds of thousands of people without the necessary medicine.
Perhaps the solution is that Viagra, Lipitor and Procepia - the anti- baldness pill - should be sold at a price that includes a supplementary charge. The money raised from this should by directed towards the provision of medicine in Third World countries and to the installation of clean water supplies, the prerequisite for health. What a wonderful thing if newly invigorated man in the West knew that his enjoyment was contributing to health and happiness in less fortunate regions of the globe. It could make him even happier.