HEALTH HORIZONS : MEDICINE : Z-Z-Z-Z-Z-Z : WELCOME TO THE WORLD OF THE SLEEP-DEPRIVED: NORMAL, HEALTHY PEOPLE WHO REPEATEDLY GET LESS SLEEP THAN THEIR BODIES NEED. FOR MANY AMERICANS, TRANSIENT SLEEPINESS HAS TURNED INTO A CHRONIC CONDITION.
Geoff Long was having trouble getting the words out. It was an easy question and he knew the answer right off. But Long, press secretary to the chairman of the state Assembly Ways and Means Committee, was astonished to find himself tripping over his tongue and tumbling into long, embarrassing pauses when he tried to reply. “I knew what I wanted to say but the words just wouldn’t come,” he remembers.
Long’s boss, Assemblyman John Vasconcellos (D-Santa Clara), had a different problem after a string of 16-hour days at the Legislature. As soon as he would get on the road for home, his eyes would start to close. But years of late-night political huddles had led Vasconcellos to develop a system: He opened all the windows and put the top down on his convertible to get maximum wind in his face. Even so, he had to slap his cheeks repeatedly to stay awake.
Long’s wife, Joyce Terhaar, wasn’t working 16-hour days. Hers ran closer to 24 hours, if their son, Connor--a newborn at the time--felt like staying awake. One afternoon after four nights up with a fussy Connor, Terhaar could think of only one way to amuse him: pulling a string on a musical toy over and over for 45 minutes. “I couldn’t even smile or talk to him,” she recalls.
Welcome to the world of the sleep-deprived. They are normal and, for the most part, healthy people who--because of work, social obligations, new babies, maybe an addiction to late-night TV--repeatedly get less sleep than their bodies need.
The problem is growing, researchers say, so much that Congress has created a commission to study its dimensions, causes and consequences and to recommend a sleep policy for the nation.
Inadequate sleep shows up in more than yawns and smudged eyes. A tax auditor may be more prone to making errors, a teacher more likely to explode at rambunctious students, an artist or writer or composer more apt to grope for inspiration.
There are safety considerations as well.
“What is the contribution of sleepiness to auto accidents? How sleepy is the night-shift at the local nuclear power plant? How many people get insufficient sleep because of their lifestyles, and what are the important public-health issues related to lack of sleep?” asks Andrew A. Monjan, executive secretary to the National Commission on Sleep Disorders Research. “These are some of the questions we will try to answer.”
Babies have always kept new parents awake, and even a century ago someone as key to hammering out a state budget as Vasconcellos might have worked his staff into the night. So these events alone do not explain the burgeoning numbers of sleepy Americans.
Researchers blame cultural, sociological and economic factors for turning what used to be transient episodes of sleepiness into a chronic condition for many Americans.
David F. Dinges, a sleep scientist at the University of Pennsylvania, cites the modern drive to “have it all.”
“Today we are told you can have a career, you can have leisure time, you can have quality time with your kids and, of course, you have to have your health time, which is the daily workout at the club,” Dinges says. To squeeze it all in, many people resort to setting the clock’s alarm to an earlier hour or to staying up later. The consequence is a sleep deficit that grows through the week, affecting job performance, personal relationships, creativity, alertness and general enjoyment of life.
Added to this is the growing number of “shift” workers in the American economy, who work something other than a 9-to-5 schedule. In the most recent study (1985) by the U.S. Bureau of Labor Statistics, 11.6 million people, or 16% of the labor force, fit into that category. Another more recent study reported in the New England Journal of Medicine estimates that 7.3 million Americans work a true night shift, reporting for work when most people are going to bed and leaving at sunrise.
Shift work hardly existed before Thomas Edison invented the electric light bulb. Most people arose with the sun and went to sleep when it was too dark to do anything else, a rhythm of life that roughly complemented the biological or circadian rhythms that control the body’s sleep/alert sensations.
The circadian clock programs the human system to be alert and active usually between the hours of 7 a.m. and 11 p.m., and reduces that stimulation during the hours when people are most likely to be asleep, 11 p.m. to 7 a.m.
There also appears to be biochemical support for the tradition in some cultures of afternoon naps or siestas, roughly between the hours of 1 and 3, when there is a measureable letdown in energy, according to Merrill M. Mitler, a sleep psychologist and director of research at the Sleep Disorders Center of the Scripps Clinic and Research Foundation in La Jolla. But reliable artificial light created an incentive to ignore these natural tendencies. Suddenly it was possible for industries to operate around the clock. It was not difficult for a factory owner to figure out that three shifts produced more salable goods than one. Soon, many people besides firefighters, police officers and hospital workers were working in the middle of the night.
Society’s drive to push back the night did not stop with factory owners. Today, many stores stay open until 9 p.m., and some operate 24 hours. Even banks have added night and Saturday hours. The trend, researchers say, affects not only workers in extended-hour service industries but also those who have completed their workday. The environmental hubbub, full of enticements to run one more errand or schedule one more appointment, makes it an almost Herculean act to remain home for a restful evening. Bedtime inevitably gets pushed off.
Most adults need between seven and eight hours of sleep a night, although, scientists say, the amount declines in older age. The amount of sleep each person needs is believed to be genetically programmed, despite the common boast of hard chargers that they have trained themselves to do with less sleep than they once required. In fact, say researchers, such people have merely trained themselves to function with a chronic sleep deficit.
Mary A. Carskadon, director of the sleep-research laboratory at Bradley Hospital in East Providence, R.I., and professor of psychiatry at Brown University, studied the behavior and performance of college students restricted to five hours of sleep a night.
“We had them on this schedule for a week,” Carskadon says. “After one day, they weren’t too badly off. After two days, there was some measureable impairment, and it got worse each day after that. If you put it in the context of a workweek, on Monday you might perform well despite inadequate sleep, but by Friday you would be in very bad shape.”
Bad shape does not mean being at death’s door.
There is little evidence that reduced sleep in humans, even if it goes on for months or years as it can with people who work night shifts, is life-threatening. Studies of rats deprived of all sleep for several weeks showed radical and ultimately fatal disruption in metabolism but, for obvious reasons, the experiment has never been tried on humans.
What bad shape does mean is cranky, miserable, uncreative, unmotivated, distracted, forgetful and sometimes a little depressed.
“People approach problems in a less efficient way,” Mitler says. “They tend to persevere with unsuccessful methods, unable to shift to better ones. Sleep deprivation increases the likelihood that people will be overwhelmed by complex tasks.”
One of the tasks facing Vasconcellos on a grinding June day as the legislative session hurtled to a close was getting the Ways and Means Committee to come to order.
The 59-year-old California assemblyman had been adhering to a strict schedule that had him at the racquetball courts at 7 a.m. and in his office by 8:30 a.m. In June, the state budget typically is working its way toward resolution at the same time that 700 pieces of legislation must move through Ways and Means. Vasconcellos generally does not leave until midnight or stop for lunch, grabbing a supper of pizza sometime during the evening.
“I’m double- and triple-scheduled most of the time with people lined up outside my door all the time and people calling constantly on the phone,” Vasconcellos says. “But the atmosphere is so intense that I never really feel sleepy, even if I’m getting only three to four hours of sleep a night.
“What goes is my own capacity to sustain myself. I feel fragile. I’m easily offended. I do things I wouldn’t ordinarily do.”
Which is how he reacted to noisy colleagues on the Ways and Means Committee.
“My colleagues were incessantly talking and laughing, interrupting my running of the committee,” Vasconcellos recounts. “I asked them to quiet down. I asked them again, and when they didn’t, I really erupted. I just got up and walked out and didn’t come back for three hours.”
Vasconcellos probably wouldn’t consider himself a night-shift worker, but simply a hard worker with a lot of responsibility requiring that he stretch the workday at both ends. How many others there are like him has not been measured, but they have sleep researchers and government officials worried, says Monjan of the sleep commission.
“These are the people who make the major decisions. They may be heads of companies, congressional leaders. There is a macho ethic that supports these long hours, but what are the consequences?”
Dinges, who directs sleep research at the Institute of Pennsylvania Hospital, scoffs at those who argue that they have methods of coping effectively with less than their biological sleep quotient.
“When you are chronically sleep-deprived, you lose your ability to judge your alertness,” he says.
The longest sleep-deprivation study on humans lasted 12 days, says Dinges. At the end, the subjects suffered misperceptions, loss of fine motor skills, memory problems and cognitive slowing, and they were unable to pick up on key perceptual signals.
“Your ability (to concentrate) is completely gone,” says Dinges. “You get very stubborn, insisting on a method that hasn’t worked, and you can’t shift.”
Brown’s Carskadon has found that creativity suffers in people operating with a sleep deficit.
“One of the things that goes is the capacity for divergent thinking--loss of the ability to free-associate,” she says. “It might be harder to do a crossword puzzle or develop a successful ad campaign after several days of inadequate sleep.”
In industry, the concern is over the quality of work performed on odd shifts. Sleep deprivation may be harder to detect in a basketball player whose work involves constant motion and physical exertion, with the added stimulation of competition. But in a desk-bound worker, whose job demands finely focused attention to detail, inadequate sleep can dramatically affect performance.
Monjan cites the catastrophic nuclear accidents at Chernobyl and Three Mile Island and the fatal chemical leak at the Union Carbide plant in Bhopal, India, as incidents at least partly attributed to human error on the night shift.
Says Dinges: “We now have a lot more automation in the workplace. In our cars we have power steering, multi-speaker sound and cruise control. So that leaves people with the one task they don’t do well when they are sleepy: Monitor the machines.”
It is not simply inadequate sleep that plagues night-shift workers who may put off sleep in order to spend time with family or others on a conventional schedule. It is the quality of sleep during daylight. The biological clock, which took millions of years to evolve as a regulator of physiological function, appears strongly linked to the daily cycle of sunlight and darkness.
That was demonstrated in a study by Charles Czeisler of Harvard University’s Center for Circadian and Sleep Disorders Medicine at Brigham and Women’s Hospital in Boston. Czeisler found that night-shift workers’ alertness, physiological systems, job performance and quality of daytime sleep matched that of daytime workers only if they were exposed to very bright light during their work hours and returned home to sleep in a completely darkened room.
Subjects who were exposed at work to bright light approximating the intensity of sunlight changed their sleep/wake rhythms by the fourth day, Czeisler reported in the New England Journal of Medicine in May, 1990. Normal indoor lighting was not sufficient to flip-flop the circadian clock. A control group of subjects, men aged 22 to 29, working in normal office light, did not adapt by the sixth night.
Other researchers are looking into theories that inadequate sleep lowers the body’s resistance to illness.
Dr. James M. Krueger, professor of physiology at the University of Tennessee, has approached the question by studying the impact of illness on the body’s need for sleep.
“Everyone seems to know that when you are sick, you sleep more,” Krueger says. “Physicians always tell patients to go home and get rest, but until now there has been no scientific evidence to support that it does any good.”
What Krueger and his colleagues found was that rats and rabbits produced more cytokines--proteins that boost the immune system--when they were fighting a bacterial or viral infection. Some of these cytokines were found to have the additional effect of inducing sleepiness in the animal, biochemically linking the animals’ disease-fighting efforts to an increased need for sleep. Krueger cautions that animal sleep patterns differ greatly from human, and that human studies confirming the link between immune response and sleep needs remain to be done. But the animal experiments lend the first scientific support to what has long been popular wisdom: When you are sick, go to bed early and sleep late.
Joyce Terhaar and Geoff Long managed to stay healthy during those first bleary-eyed weeks of parenthood, but sleepiness became a constant, day and night. Gradually, though, Connor settled down, letting his parents indulge their sleep cravings for as long as four hours at a stretch. One day, Geoff actually got away from the Capitol early and spelled Joyce so that she was able to get an unbroken night’s sleep. The next day she discovered what so many do on Saturday and Sunday after burning the candle ends all week: A sleep deficit built over several days can be erased by one extended night of sleep.
Things were going so well, in fact, that the couple decided they were ready for a night out with friends.
“We went to their house and we brought Connor,” Terhaar recalls. “He was really good between 6 and 10--usually his fussy period--so we had a nice time and were in a really good mood coming home. But then, as soon as we got home, he started fussing, and it lasted until nearly midnight. It was as if he put it off just to keep us up again.
“We just sat there completely unable to deal with it. When you’re tired you just can’t deal with the frustration, I guess.”
