National Geographic : 2010 May
roughly a h of the population, complain about problems sleeping. Fi y-six million prescriptions for sleeping pills were written in 2008, up 54 per- cent over the previous four years. e revenue for sleep centers is expected to approach four and a half billion dollars by 2011. Yet remarkably little is being done to understand the root causes of insomnia. Most medical school students get no more than four hours of training on sleep disorders; some get none. Family doctors' health questionnaires o en don't even ask about sleep. The social and economic costs from the undertreatment of sleeplessness are huge. e Institute of Medicine, an independent national scienti c advisory group, estimates nearly 20 percent of all serious motor vehicle accidents are associated with driver sleepiness. It places the direct medical cost of our collective sleep debt at tens of billions of dollars. The loss in terms of work productivity are even higher. en there are the so er costs---the damaged or lost relationships, the jobs tired people don't have the energy to apply for, the muting of enjoyment in life's pleasures. If a medical problem in some less private, less mysterious bodily function were causing such widespread harm, governments would declare war on it. But the National Institutes of Health contributes only about $230 million a year to sleep research---comparable to the amount that the manufacturers of the popular sleeping pills Lunesta and Ambien spent in one season on television advertising in 2008. e military also spends money investigating sleep, but its primary mission is keeping soldiers up and ready to ght, not ensuring they get a good night's rest. As a result the ght against insomnia is largely le to drug companies and commercial sleep centers. "Sleep has been the Rodney Dangerfield of medicine," says John Winkelman, medical director of the Brigham and Women's Hospital's Sleep Health Center in Brighton, Massachusetts. "It just gets no respect." last year I paid a visit to the Sleep Medicine Center at Stanford. e clinic, founded in 1970, was the rst in the coun- try devoted to the problem of insomnia, and it remains among the most important. e sleep center sees over 10,000 patients a year and does more than 3,000 overnight sleep studies. The 18 bedrooms that patients occupy looked com- fortable, the beds so and cozy. e monitoring equipment was hidden in the furniture. e main diagnostic tool at the clinic is the polysomnogram, the main element of which is the electroencephalograph (EEG), which cap- tures the electrical output from a sleeping pa- tient's brain. As you fall asleep, your brain slows down, and its electrical signature changes from short jagged waves to longer rolling ones, much the way the movement of the sea smooths out the farther you get from shore. In the brain these gentle undulations are interrupted periodically by a renewal of the sudden agitated mental Lamb brains develop in utero on a course similar to human brains, allowing Matthias Schwab of Friedrich Schiller University, Germany, to use sheep as a window into prenatal sleep. He attaches electrodes to a fetal lamb's brain (above) and returns it to the womb for monitoring (le ). His research suggests that fetal slumber is predominantly deep sleep, not REM sleep as once thought.