In the industrialised world, say a growing number of scientists, we have a sleep crisis: we're badly in the red, and the debt mounts each year. The German scientist Thomas Wehr believes that sleep deprivation is now the norm, and that few people know what it is to feel properly rested. In the Fifties, sleep was thought of as a passive process; it was discovered only relatively recently that, although activity is reduced in the parts of the brain that control emotion, decision-making and social interaction, the brain remains very active during the night. Now it is accepted that the amount and quality of sleep we get has an effect on our mental health and how well we function while awake. Lack of sleep, it turns out, impairs our memory, physical condition, concentration and immune system. Severe, prolonged sleep deprivation will cause mood swings and hallucinations, which is why there are occasional reports of teenagers keeping themselves awake for days on end in search of an alternative high.
In America, Sleep Awareness Week has taken off, and so too has the idea of the power-nap (for which offices provide special "quiet" rooms). Only this week, a Professor Maas of Cornell University in New York, who runs a course of Power Sleep classes, claimed that less than eight hours per night makes people "stupid". He cited the case of Einstein, who insisted on 10 hours per night, and 11 if he was planning to do mathematical work the next day. A black mark to Lady Thatcher, then, who got by on only four hours' sleep while in office; a gold star to Tony Blair, who jealously guards his eight hours.
More research into sleep is being carried out than ever before. These are some of the "facts" produced: over the past century the amount of time we spend sleeping has been reduced by a fifth; in developed countries the average night's sleep is down half an hour from the Seventies; every adult in America sleeps 500 hours fewer per year than they actually need; losing a night of sleep has a similar effect on the reflexes as a blood alcohol level of 0.08 per cent, the drink-drive limit in this country; lack of sleep causes depression and increases stress. (Conversely, one treatment for severe depression is to sleep less. Such are the vagaries of human biorhythm research.)
Bearing all this in mind, is it any wonder that so many of us are obsessed with sleep? Insomnia has come to be regarded as a disease, or at the very least a symptom of a troubled mind, whereas the ability to always slide easily into a deep sleep indicates a sublimely unencumbered nature. The final proof of the uniqueness of our internal worlds, there can seem nothing so exclusive or desirable as sleep to those who are denied it. And nothing feels more solitary than a night spent in the unsuccessful pursuit of it. Everyone is familiar with the image of the single lighted window in a dark city; with the sound of the waking birds and the gliding milk float as one continues to do battle with the pillows; with the cold comfort offered by late-night radio-babble or by trips to the kitchen for Grape- Nuts. The great trick, of course, is not to mind. Those who like to treat the night as day are particularly enviable - it somehow seems rebellious, courageous, to opt to remain conscious during the hours others spend in oblivion.
The putative treatments for insomnia are endless: whisky, reading, camomile, Valium, and so on. Charles Dickens, in his essay Night Walks, described the solution he found to a series of sleepless nights one cold March: he would rise soon after going to bed, at about midnight, and would go and wander the streets. He referred to the condition as "Houselessness" - he found himself identifying with the homeless, since his aim, like theirs, was to make it through the night. On one of these nocturnal promenades he ventured near Bedlam: "partly, because I had a night fancy in my head which could be best pursued within sight of its walls and dome," he wrote. "And the fancy was this: Are not the sane and the insane equal at night as the sane lie a-dreaming? Are not all of us outside this hospital, who dream, more or less in the condition of those inside it, every night of our lives? ... Do we not nightly jumble events and personages and times and places, as these do daily?"
When we sleep, and for how long, is evidently all down to our circadian rhythms. A century and a half ago the sun was a bossy celestial Matron telling people when to go to bed and when to get up. Now electric light makes it far easier for us to postpone sleep, the upshot of which is that we sleep until later in the day. We are out of touch with our natural daily cycles. The general consensus is that our "low" times - when the pulse slows, the temperature drops, and we most need to sleep - are in the early afternoon and at about 9pm, as darkness descends. This is borne out by the fact that these times are accident "blackspots": the Exxon Valdez, Chernobyl and Three Mile Island disasters all occurred during the late-shift, and most car crashes happen after lunch or at night. Medical interns are twice as likely to misinterpret hospital test results when they're on night duty.
Another problem arising from the alteration in our sleeping habits is that we no longer see as much natural light as people did back in the days when they went to bed at nightfall and woke at dawn. In temperate climates, the natural way to deal with shorter days and longer nights is to sleep more: Scandinavian children sleep on average two hours longer in winter than in summer. Yet modern life makes it impossible for most people to adapt this easily - anyway, they cannot just turn into Rip Van Winkle in the darker months - and this can lead to Seasonal Affective Disorder, or winter depression. Scientists have discovered that one of the best ways to treat this is to expose sufferers to strong ultraviolet light in the morning (this is the cure being taken by the wan-looking folk in the snow, swaddled in smart health-club dressing gowns).
New research suggests that while we may be deprived of natural rays, we may be being exposed to too much artificial light, thus hindering our production of the hormone melatonin, which is produced only in near complete darkness. This has the same effect on the system as sleeplessness and other circadian disturbances. In addition, scientists are investigating a possible link between disrupted melatonin production and breast cancer.
The lesson from the wonderful world of science is clear: respect your circadian rhythms. You can get by on less sleep than you need, you may even get used to being tired, but you can't stint on sleep and still feel awake. 1Reuse content