America, the home of the free, is also land of the tired, with sleep a casualty of the non-stop pace at which we live, reports Correspondent Jerry Bowen.
We pack our days so full that there's not a moment left over for sleeping, a human need as basic as breathing. Nowhere is that more apparent than on metropolitan area commuter trains.
Ed Hall, an ad executive by day and an artist after hours, has been sketching sleeping commuters on the Long Island Railroad for 14 years. "Some thrash, sleep in fits and starts. Some are out like a light, banging
their heads against the window," Hall says.
Americans, on average, sleep two fewer hours every night than they did a few decades ago, but this doesn't mean they need less sleep.
David Dinges, an expert on sleep disorders at the University of Pennsylvania, says most people need eight hours of sleep a night.
"We recognize the individual differences in the need," he says, "but fundamentally it looks like whenever you chronically reduce sleep, even in small amounts, and make people live on seven, six, five or four hours a night, you get these escalating impairments. The brain becomes unstable during wakefulness. Attention wanes. You can't remember things as well."
Scientists know very little about the purpose of sleep. They can't even say for sure whether sleep is exclusively for the mind or the body. In what has become an extremely hot topic for scientists, the race is on to solve the mysteries of sleep, not just to gain knowledge, but also to treat the more than 80 different types of sleep disorders being diagnosed these days.
Dr. Gary Zammit, who runs the sleep disorder clinic at St. Luke's Roosevelt Hospital in New York, says that National Sleep Foundation data show that 42 percent of Americans are not getting the sleep they say they need to function well during the day..
One of the most common sleep disorders is insomnia. Occasional insomnia affects somewhere between 36 and 56 percent of American adults. Chronic on-going difficulty sleeping affects somewhere between 9 and 17 percent of adults.
The biggest problem doctors face in treating the legion of sleepless is getting people to regard being tired, or having trouble sleeping as a serious, medical condition with symptoms that effect health and quality of life.
At the Van Cauter Lab at the University of Chicago, Eve Van Cauter is gathering scientific evidence that may prove lack of sleep affects our bodies as well as our minds.
"We are curtailing our sleep dramatically and we are also seeing now an epidemic of obesity and diabetes," she says. "Is there a relationship between the two?"
In a recent study, reported in The Lancet, Van Cauter studied the effects of limited sleep on a group of healthy young men. After four nights of four hours of sleep a night, they were essentially in a pre-diabetic state.
"We did not expect to see a change of that magnitude," she says. "That was a surprise."
Inadequate sleep has also been linked to hypertension and weakened immune systems.
But no one ever hears executives talk about how to get their workers to get more sleep.
As a result, another area of scientific inquiry is about how to keep people awake. That's where a new drug called modafinil comes in..
Dr Paul Blake, who is coordinating clinical studies of the drug for Cephalon, the company that makes it, says researchers don't know how it works but it fools the brain into a state of wakefulness at any hour - without any of the nasty side effects of older amphetamines, like jitteriness, increased pulse and heart rate.
Already approved by the FDA to treat the sleep disorder narcolepsy, the hope is that one day Modafinil could be used for shift workers who need to fool their body clocks just to do their jobs.
Blake says, "People with the need to work shifts suffer from two sorts of problems in general. They tend to be sleepy when they are trying to be awake, and they tend to be awake when they are trying to be alseep. That can have great difficulties for them in performance of their work and leading the rest of their lives when they are not at work."
Modafinil has also caught the attention of the United States military. At the U.S. Army Aeromedical Research Center at Fort Rucker in Alabama, researcher John Caldwell is conducting simulator studies of modafinil in Blackhawk helicopter pilots, who often have to fly long missions with no sleep.
"While they were on the drug," Caldwell said, "their behavior was almost at the same level as it was when they were well rested, despite the fact that they had been awake 24, 30 even 35 hours."
The danger of a drug like that, says Dinges, the sleep specialist, is that the general public will use it to try to do away with sleep altogether.
Scientists, looking to alter the brain chemistry that makes us sleep, are studying killer whales who are able to sleep with one half of their brain at a time.
UCLA researcher Oleg Lyamin is studying the sleep patterns of Nakai, the baby killer whale at Sea World, and his mother Kasakta. He's hoping to understand how the two halves of the killer whale brain shift between wakefulness and sleep and whether this might shed light on how humans can control their own brain's on/off switch.
Science can only give us tips that will help us get a good night's sleep.
"We have forgotten our grandmother's wisdom and we are trying to live outside the boundaries of biology," says Van Cauter. "We are not made for sleep deprivation."