Tom Hodgkinson: The best thing to do after learning new information is to take a nap

Dr Johnson's favourite book was Robert Burton's bestselling 17th-century self-help guide The Anatomy of Melancholy. This exhaustive manual on madness and depression, first published in 1621, was so popular that, it was said, its publisher "got an estate by it". Johnson said it was the only book which would get him out of bed early.

Its popularity suggests that there may have been an epidemic of misery in the early 17th century. Certainly it was a difficult time in British history: the previous 100 years or so since the Reformation had seen a destruction of the welfare and education systems which had previously been operated by the Church. The growing Puritan tendency in England had seen the old customs of merry-making and collective festivity under attack, and their new emphasis on the individual rather than the community might also explain why so many people were depressed.

Contemplation and reflection – or, in other words, doing nothing – also came under fire. The Protestant writer Richard Baxter promoted the ethic of hard work: "Be diligent in your callings," he wrote, "and spend no time in idleness, and perform your labours with holy minds."

Burton's cures for melancholy included "mirth and merry company". One excellent remedy, he says, was practised by the ancient Greek grammarian Atheneus, and went as follows: the doctor laid the patient "on a down bed, crowned him with a garland of sweet-smelling flowers, in a fair-perfumed closet delicately set out, and after a portion or two of good drink, which he administered, he brought in a beautiful young wench that could play upon a lute, sing and dance".

If only such imaginative prescriptions were offered by the NHS. Instead, our system is more likely to offer pills of some sort. Now, these less sensual cures can work, it is true: a friend recently told me that she reckoned her GP saved her life by giving her anti-psychotics. But she believes there was also a placebo at work: she liked and trusted her doctor.

One GP I met recently reckons that patients have been wrongly encouraged to seek pills for every species of low-grade misery. Sometimes, she says, sadness should simply be suffered. It may have something to teach us. Mental pain may be telling us to change something fundamental in our lives. This is the conclusion of the psychologist James Davies in Cracked, his excellent new attack on psychiatry. Suffering is part of being human, he says; we should resist the Californian attempt to destroy pain. That way lies the madness of the society painted by Aldous Huxley in Brave New World, where passion is eliminated in favour of a bland anaesthesia.

Robert Burton was careful not to recommend idleness as a cure for melancholy. Idleness would produce solitary brooding, which could make your depression worse. His famous injunction to the melancholic of temperament was: "Be not solitary; be not idle." However, Dr Johnson adapted this formula to read: "When solitary, be not idle; when idle, be not solitary." There was nothing wrong with doing nothing, Johnson thought, as long as it was done in company.

A terrific book has just landed on my desk which backs these old authorities. Auto-Pilot: The Art and Science of Doing Nothing by American scientist Andrew Smart argues that the brain needs idleness. The author uses the latest findings in neuroscience to argue that doing nothing leads to happiness. "Recent research is revealing that some forms of self-knowledge may only appear to us in idle states," writes Smart. In our frantic chase for gain, we suppress "our brain's natural ability to make meaning out of experience". Idleness is especially important after taking in new facts or skills. "If you relax for a while, the hippocampus more or less writes these memories to your neocortex, which houses your long-term memories... So the best thing to do after learning new information is to take a nap, or at least be idle." Be happy, be clever, be idle.

Tom Hodgkinson is editor of 'The Idler'