NEW YORK (Reuters Health) - Recovering alcoholics sleep worse than people who have never had a drinking problem, and this difference persists after months or even years of abstinence, new research shows.
These changes probably worsen the problems with mental function that result from long-term heavy drinking, Dr. Ian M. Colrain of SRI International in Menlo Park, California and his colleagues say.
People who abuse alcohol complain of insomnia and other sleep problems, even after periods of abstinence, Colrain and his team note in the October 1 issue of SLEEP. But little is known about how alcoholism affects sleep in women, and whether the sleep changes persist long-term.
To investigate, the researchers monitored brain electrical activity during one night’s sleep for 42 alcoholics and 42 people without alcohol problems. The alcoholics had been sober for 179 days, on average, with periods of abstinence ranging from 10 days to nearly two years. Fifteen of the alcoholics were women.
All had met criteria for alcohol dependence, and their average consumption was equivalent to about eight pints of whisky a week, Colrain told Reuters Health: “This is not social drinking.”
The researchers looked at how long the subjects spent in two types of sleep: slow-wave and REM. Slow-wave sleep is essential for helping the brain to consolidate learning and memory, while REM sleep is when most dreaming happens.
Non-alcoholic men and women spent 12 percent of their sleeping time in slow-wave sleep, and around 20 percent in REM sleep, the researchers found.
But the time in slow wave sleep for alcoholic men was about 7 percent, and for women it was 11 percent. REM sleep represented 24 percent of total sleep time for alcoholic men and women.
Alcoholic individuals also spent a bit more time in stage 1 sleep, the lightest sleep stage, than non-alcoholics did.
While getting less slow-wave sleep is likely to be harmful, he added, getting more REM sleep “is probably a good thing, and certainly not a bad thing,” Colrain said. But overall, the differences appear to reflect long-term changes in the brain that affect how sleep is regulated, and they seem to be similar in men and women.
Despite the findings, Colrain told Reuters Health, “it’s likely that the sooner you stop drinking the less the impact will have been and the more likelihood you’ll have to recover.”
The National Institute on Alcohol Abuse and Alcoholism funded the study.
SOURCE: SLEEP, October 1, 2009.