Alertness, memory, job performance and mood all depend on adequate sleep. In fact, sleep deprivation can impair your thinking as much or more than alcohol.

So what's keeping Americans from making time for sleep?

Too many of us are not getting the sleep we need, taking a serious toll on our professional and personal lives, according to a 2008 Sleep in America poll conducted by the National Sleep Foundation (NSF).

No one is saying you should worry about the occasional poor night's sleep but when sleep deprivation is chronic, the effects can be devastating. Witness the Exxon Valdez oil spill and NASA Challenger shuttle explosion. Both tragedies have been linked to fatigue-related human error.

Thomas J. Balkin, Ph.D, the vice chair of the NSF sums up the evidence this way:

Studies show that habitually getting inadequate sleep creates long-lasting changes to one's ability to think and function well during the day.

Ouch.

If you believe you're one of the rare individuals who can get by without much sleep, first, think again, then consider the following:

• Sleep deprivation and sleep disorders cost Americans more than $100 billion every year in lost productivity, medical expenses, sick leave, and property and environmental damage, estimates the NSF.
• 100,000 car crashes are caused by drowsy drivers each year, according to conservative estimates by the National Highway Traffic Safety Administration.
• The effect of lost sleep is similar to being drunk. One study cited by the NSF in a report titled "Why Sleep Matters" showed that people who were awake for up to 19 hours scored substantially worse on performance and alertness than people who were legally intoxicated.
• Inadequate sleep can negatively impact your judgment, reaction time and memory.
• "When you're sleep deprived, you're more likely to develop infections, high blood pressure, cardiovascular disease and diabetes," according to a MayoClinic.com article on insomnia.

For some, less sleep can be seen as a lifestyle "choice."

With jobs, families and all the demands on our time, we decide to sacrifice our sleep in order to get everything done. For others, a sleep disorder is to blame. For both groups, experts warn sleep should be a priority.

"Similar to diet and exercise, sleep needs to be an integral element of a healthy lifestyle," says the NSF's acting CEO Darrel Drobnich.

Otherwise our health, as well as our relationships, careers and safety can suffer.