How common are sleeping problems?

Some studies show that as many as six out of 10 adults claim to have problems sleeping a few nights or more per week. Sleeping pill sales figures tend to support this claim, with more than $3.7 billion spent on sleeping pills in 2007.

Forty percent of adults report some daytime sleepiness that reduces their productivity at least a few days every month, other studies show. About 20 percent are sleepy a few days or more every week.