People who get only 6 to 7 hours a night have a lower death rate than those who get 8 hours of sleep. —From a six-year study of more than a million adults

Many Americans are sleep-deprived zombies, and a quarter of us now use some form of sleeping pill or aid at night.

Wake up, says psychiatry professor Daniel Kripke of the University of California, San Diego. The pill-taking is real but the refrain that Americans are sleep deprived originates largely from people funded by the drug industry or with financial interests in sleep research clinics.

"They think that scaring people about sleep increases their income," Kripke told LiveScience.

Thanks to the marketing of less addictive drugs directly to consumers, sleeping pills have become a hot commodity, especially in the past five years. People worldwide spent $2 billion on the most popular sleeping pill, Ambien (zolpidem), in 2004, according to the BioMarket, a biotech research company.

Earlier this month, it was reported that some Ambien users are susceptible to amnesia and walking in their sleep. Some even ate in the middle of the night without realizing it.

Global sales for all sleeping pills, called hypnotics, will top $5 billion in the next several years.

Some Serious Shut-eye Improved sleep behavior and attitudes do more good than sleeping pills for the treatment of insomnia, experts at a recent National Institutes of Health Consensus Conference agreed, says Daniel Kripke of the University of California, San Diego. The changes he recommends: Some Serious Shut-eye Improved sleep behavior and attitudes do more good than sleeping pills for the treatment of insomnia, experts at a recent National Institutes of Health Consensus Conference agreed, says Daniel Kripke of the University of California, San Diego. The changes he recommends:

Do not take sleeping pills. This includes over-the-counter pills and melatonin.

This includes over-the-counter pills and melatonin. Don't go to bed until you're sleepy. If you have trouble sleeping, try going to bed later or getting up earlier.

If you have trouble sleeping, try going to bed later or getting up earlier. Get up at the same time every morning, even after a bad night's sleep. The next night, you'll be sleepy at bedtime.

every morning, even after a bad night's sleep. The next night, you'll be sleepy at bedtime. If you wake up in the middle of the night and can't fall back to sleep, get out of bed and return only when you are sleepy.

in the middle of the night and can't fall back to sleep, get out of bed and return only when you are sleepy. Avoid worrying , watching TV, reading scary books, and doing other things in bed besides sleeping and sex. If you worry, read thrillers or watch TV, do that in a chair that's not in the bedroom.

, watching TV, reading scary books, and doing other things in bed besides sleeping and sex. If you worry, read thrillers or watch TV, do that in a chair that's not in the bedroom. Do not drink or eat anything caffeinated within six hours of bedtime.

anything caffeinated within six hours of bedtime. Avoid alcohol . It's relaxing at first but can lead to insomnia when it clears your system.

. It's relaxing at first but can lead to insomnia when it clears your system. Spend time outdoors. People exposed to daylight or bright light therapy sleep better.

The number of adults aged 20-44 using sleeping pills doubled from 2000 to 2004, according to Medco Health Solutions, a managed care company. Sleep problems are commonly reported in the elderly, but the increase in spending on sleeping pills was highest in this period for 10-19 year olds, possibly due to an association with medication for attention deficit hyperactivity disorder (ADHD).

Sleep on this

Still, more sleep is no guarantee for overall health, and more sleeping pills might not bring on either.

A six-year study Kripke headed up of more than a million adults ages 30 to 102 showed that people who get only 6 to 7 hours a night have a lower death rate than those who get 8 hours of sleep. The risk from taking sleeping pills 30 times or more a month was not much less than the risk of smoking a pack of cigarettes a day, he says.

Those who took sleeping pills nightly had a greater risk of death than those who took them occasionally, but the latter risk was still 10 to 15 percent higher than it was among people who never took sleeping pills. Sleeping pills appear unsafe in any amount, Kripke writes in his online book, "The Dark Side of Sleeping Pills."

"There is really no evidence that the average 8-hour sleeper functions better than the average 6- or 7-hour sleeper," Kripke says, on the basis of his ongoing psychiatric practice with patients along with research, including the large study of a million adults (called the Cancer Prevention Study II).

And he suspects that people who sleep less than average make more money and are more successful.

The Cancer Prevention Study II even showed that people with serious insomnia or who only get 3.5 hours of sleep per night, live longer than people who get more than 7.5 hours.

And there are questions about the effectiveness of sleeping pills. A study by researchers at Beth Israel Deaconess Medical Center and Harvard Medical School found that a change in sleep habits and attitudes was more effective in treating chronic insomnia, over the short- and long-term, than sleeping pills (specifically Ambien).

Night of the living dead

Until 15 years ago, sleeping pills were mainly addictive, overdose-risky barbiturates (such as Seconal) and sedatives called benzodiazepines (Valium and Dalmane). For these reasons, they were less popular and less prescribed. That changed in the early 1990s when Ambien, which is less addictive, came on the market. It acts on the same neural receptors as a benzodiazepine, but is safer. It is the only hypnotic drug Kripke recommends and then, only for fewer than four weeks. Other new hypnotic drugs are safe but ineffective, he says.

Most sleeping pills are recommended for short-term use, but lots of people take them frequently and become dependent upon them to fall asleep. Most sleeping pills, especially when taken over long periods of time, stay in the bloodstream, giving a hangover the next day and beyond, impairing memory and performance on the job and at home.

A time-release version of Ambien (Ambien CR) bound for the market and designed to prevent waking after 4 hours when the drug normally would wear off, along with one of the newest pills on the market, Lunesta, or eszopiclone, (designed for longer-term use) might be even more harmful in this way, Kripke says.

Hypnotic drugs have dangerous side effects, Kripke says. For one, they reduce fear of risky behavior, such as driving fast. Ironically, that could result in the inability to see that the sleeping pills are doing more harm than good over time.

A recent study published in the British Medical Journal showed that the risks of taking sleeping pills (benzodiazepines and other sedatives, in this case) outweighed the benefits among people over 60 in a series of studies carried out between 1966 and 2003. The pills helped people fall asleep and they slept more, but they were twice as likely to slip and fall or crash a car due to dizziness from the pills than they were to get a better night's sleep.

Even the safest hypnotic drugs have strange side effects, as the alleged Ambien sleepwalkers showed.

And one over-the-counter approach, the hormone melatonin, was found by scientists at the University of Alberta, Canada, to be ineffective in treating jet lag and sleep trouble associated with medical problems. Studies also show it is associated with skin blanching in frogs, gonadal atrophy in small animals, and obesity in some mammals.

Are you sleeping?

The real number of Americans with sleep problems is unclear because the same figure—70 million—appears on National Institutes of Health documents from 2006 and from 1994. This catch-all category reportedly includes insomnia, jetlag, sleepwalking, bed wetting, night terrors, restless legs syndrome, narcolepsy and disordered breathing during sleep (called apnea).

The National Sleep Foundation, the source of many sleep surveys and statistics, has financial and institutional ties to sleeping pill manufacturers, according to the Sacramento Bee newspaper.

Sleep problems could be increasing, Kripke says, but there is no evidence for this. If they are increasing, it could be a result of less exposure to daylight (due to cable TV, the Internet, indoor gyms) and increasing obesity, which causes apnea. But he still recommends against taking sleeping pills in nearly all cases and in favor of improved sleep habits.

"Sleeping pills usually do more harm than good," he says.