In a world that runs around the clock, most people aren't getting enough sleep--and the consequences of our nationwide sleep deprivation range from compromised immune systems to car crashes caused by drowsy drivers. That's what psychologist David Dinges, PhD, of the University of Pennsylvania School of Medicine, told audience members at a May 10 congressional briefing to educate legislators about sleep and safety issues.

"I'm going to give you a message that I suspect your mother or grandmother probably gave you," he said. "Getting an adequate duration of good quality sleep promotes health, safety, productivity and overall well-being."

At the briefing, Dinges received the Decade of Behavior Research Award for his sleep research. The award recognizes research that has contributed to the use of social and behavioral science in public policy.

Unfortunately, he noted, more than 60 percent of Americans sleep less than seven hours per night on average and the same percentage have problems sleeping at least a few nights each week, according to the National Sleep Foundation. Also, more than three-quarters of workers say that their ability to make important decisions has been affected by sleep loss.

Dinges described some of his own research on sleep deprivation. Sleep loss, he says, leads to increased physiological pressure for sleep: Sleep-deprived people will enter deep sleep within 4 minutes of closing their eyes, as opposed to 40 minutes for nonsleep-deprived people. So, it's harder for a sleep-deprived person to remain alert and attentive during any task, including those like driving in which attentiveness is critical.

In some studies, for example, Dinges tested sleep-deprived and nonsleep-deprived people's reaction times to a bright light. He found that while the well-rested subjects were able to consistently respond quickly by pressing a button whenever they saw the light flash, the sleep-deprived subjects' reaction times were much more unstable. Other studies by Dinges indicate that chronic amounts of small sleep loss can reduce the stability of a person's reaction times as much as one night without any sleep can.

To cast further light on such problems and help find solutions, Dinges suggested that future sleep research should focus on the neurobiology of sleep; the effects of restricted sleep on children, adults and the elderly; the causes of specific sleep disorders; and new treatments. Dinges called on legislators to support federal agencies funding this research, including the National Institutes of Health, the Department of Transportation, which is doing work on drowsy driving, and the Department of Defense, which is investigating fatigue-related errors in military operations.

The briefing was sponsored by the Federation of Behavioral, Psychological and Social Sciences and by the Decade of Behavior, a 10-year multidisciplinary initiative co-sponsored by dozens of behavioral and social science organizations. The initiative aims to use those sciences to address societal issues like education, health care, safety, aging, drug abuse and many others.

--L. WINERMAN