'Doc, I've been up for three days. I need something for sleep — I feel like a dead man walking," a 26-year-old accounting student said as he was preparing for his CA exams. Though he's suffering the full effects of insomnia, his sleep difficulty is short-term, and should resolve quickly. … Yet unlike the accounting student's situational insomnia, our society is collectively suffering from a persistent lack of sleep.

Dr. Peter J. Hauri, director of the sleep disorders center at Dartmouth Medical School, says that while most sleeping pills ''are initially effective, most lose efficacy when used chronically.'' He says that sleeping aids are often appropriate ''in transient, situational insomnia, which may last for up to three weeks, but rarely are they indicated for chronic longterm use.''