Nov. 8, 2010 -- Contrary to the widely held belief, drinking alcohol does not appear to cause sleep problems, a new study finds.
"It surprises us," says study researcher Daniel C. Vinson, MD, MSPH, a professor of family medicine at the University of Missouri in Columbia. "We looked at these results every which way to see if alcohol causes sleep problems, and it just didn't come out that way." The new findings appear in the November/December issue of the Annals of Family Medicine.
Some sleep experts are not quite convinced of the findings because they were based on participants' self-reports of alcohol use and sleep issues.
In the new study of 1,699 adults from 40 different primary care practices, alcohol had no bearing on self-reported insomnia (a sleep disorder marked by difficulty falling or staying asleep), overall sleep quality, or restless legs syndrome symptoms. But people who said they used alcohol to sleep were more likely to be "hazardous drinkers."
"This may be an item that doctors should listen for," Vinson says. "If the patient says they drink alcohol at bedtime, a doctor should explore their alcohol use in greater detail.”
"If you are using alcohol to sleep, you may need to rethink your drinking habits," he says.
Alcohol Use, Sleep Problems Common
Twenty percent of women and one-quarter of men in the study met criteria for hazardous drinking based on their responses to one of two alcohol screening tests.
Sleep problems were also common in the study. Nearly half of the participants said their sleep quality was "poor" or "fair" during the past month, and about 25% said they used an over-the-counter or prescription medication at least once a week to get to sleep.
Self-Reports Not Always Believable
"If you ask people how much they drink, they will probably under-report, and if you ask about sleep problems, they will over-report," says Michael Breus, PhD, clinical director of the sleep division for Arrowhead Health in Glendale, Ariz.
"I find it hard to believe that heavy drinkers are quality sleepers," he says. "They won’t have a hard time falling asleep, but staying asleep is another story."
Heavy drinkers may wake up multiple times to use the bathroom -- and they may or may not remember these bathroom trips, he says.
Breus says the findings "don't ring true regarding the effects of alcohol on quality and quantity of sleep."
Study Results Provide Important Clues
Susan Zafarlotfi, PhD, the clinical director of the Institute for Sleep-Wake Disorders at Hackensack University Medical Center in New Jersey, says that insomniacs often self-medicate with alcohol or sleeping aids.
"Primary care physicians should ask about drinking and if someone says they drink socially, we should ask them what they mean by socially," she says. "This line of questioning may help doctors diagnose sleep disorders, which are underdiagnosed."
"Doctors are reticent to ask questions about alcohol use because they don't have the time or don't know how to bring it up," he says. "It may not be causing sleep problems, according to the study, but if you are an alcoholic you are having sleep problems."
His take-home message? "Asking people if they use alcohol to sleep is highly predictive of hazardous drinking and is a useful screen for alcohol problems," he says.