Supposedly, Edison got by on a few hours of sleep. You hear about CEOs of companies boasting about how little sleep they get.

It's just so much easier not to sleep now. There are things to do all the time -- clubs open, you could e-mail, or bank all night long. There's more competing activity chipping away at sleep.

With a lot of these pills there is a withdrawal syndrome. Anything that's sedating, if you stop taking it, can cause rebound insomnia. The combination of knowing you haven't taken the drug, which is a psychological effect, and the lack of a pharmacologic effect, are both sort of pushing toward a poor night of sleep.

I think there's a real desperation that comes from not being able to sleep. People feel they've lost control over something very basic and they start taking sleeping pills... and they do get some relief.