Americans, perhaps as many as 100 million teens and adults, don't get enough sleep--not because they can't sleep but because they are too busy working and playing.
The result, according to an article in the current issue of Esquire, is a lack of alertness that can be dangerous, particularly when compounded by alcohol.
The sleep-deprived may suffer lapses of attention and information-processing ability while they are driving, caring for children or otherwise affecting someone else's welfare.
Dr. Thomas Roth, who heads the Sleep Disorders and Medicine Division at Detroit's Henry Ford Hospital, said it is not the level of sleep loss that worries him.
"It's the ignorance of the consequences," he said. "People know eating a lot of fats makes them vulnerable to heart disease. But they think the less they sleep, the better they are.
"You have to recognize that if you're studying for exams or making deadlines and quotas, and then you have a drink to celebrate, you're in double trouble. A trivial second drink after meeting a deadline is really dangerous."
Roth's experiments include feeding vodka and tonic at 9 a.m. to volunteers who are sleepy, rested, drunk and sober.
Test results show that sleep loss and alcohol produce similar sedative effects--both make you sleep--but they also interact. Each heightens the effect of the other.
"For a hard worker sleeping five hours a night, one beer might have the same effect as three or four Scotches for someone who sleeps nine hours a night," Roth said.
Age is another factor in sleep problems, according to psychologist Richard Coleman, a specialist in chronobiology and former co-director of the Stanford University Sleep Disorders Clinic who now heads a consulting firm.
"People naturally develop more sleep disorders as they get older," Coleman said, "just as they get more heart disease and so forth. Two reasons interlock, as usual: environment and physiology; nurture and nature."
Environment involves people sacrificing sleep time in favor of work and play. Many rate themselves alert when they are not.
Physiology determines that as we reach our 20s, 30s and beyond, we have decreasing amounts of Stage 4 or deep sleep, which seems to have restorative value. It occupies about a quarter of a child's sleep time but only an eighth or less of an adult's.
"We seem to lose some flexibility in our circadian rhythms, just as we lose it in muscles and joints; we don't adjust as easily to change," Coleman said.