THURSDAY, March 1, 2012 (HealthDay News) -- The older you get, the better you sleep, according to new research that challenges conventional wisdom that a good night's rest is harder to come by with age.
In a survey of 150,000 adults, people in their 70s and 80s had the fewest complaints of sleep disturbance, while those between the ages of 18 and 24 had the most. Except for a bump in complaints in middle age, sleep appears to improve steadily over the course of a lifetime.
One big implication of the study is that health-care providers should not just dismiss poor sleep as a normal part of aging, said study author Michael Grandner, a research associate at the Center for Sleep and Circadian Neurobiology at the University of Pennsylvania.
The study, which appears in the March issue of the journal Sleep, looked at responses to a phone survey conducted in 36 U.S. states and territories. People described how often they had experienced sleep disturbance or daytime drowsiness in the previous two weeks.
"In women, you saw very clear increases in both sleep disturbance and daytime tiredness [in middle age]; in men you also saw an increase in later middle age," Grandner said. "I think in women, you're seeing an effect of pre-menopause and menopause. With men, it's a little later. That's where career peaks -- and peak stress -- occurs, in the later 50s."
Men in that age group are also at higher risk of sleep apnea and other health problems, he noted.
Health problems -- especially depression -- had a significant effect on sleep, the survey found.
"One of the most important findings was that depression was a significant predictor for sleep problems," said Michael Vitiello, a professor of psychiatry and behavioral sciences at the University of Washington in Seattle, and an expert on sleep and aging.
"I applaud the investigators for this labor-intensive and comprehensive examination of the question," he said. "I've been on the 'It isn't aging, it's illness' bandwagon for many years. It's a treatable disorder. Much of the sleep disturbance seen in older adults is not driven by aging, but by illness."
Healthy older people sleep better, both experts said. They don't necessarily nap more, and dozing off at the opera or movies is by no means a given.
In his own research, Vitiello said, "we looked at napping in older adults -- but not as large a sample, and found that, like sleep complaints, napping is driven by illness burden. If an older person complains [of sleep problems], something's going on and it needs to be dealt with. A physician shouldn't say, 'OK, you're old.' "
Treatment could include referring a patient to a sleep clinic or to a psychiatrist, Vitiello said. And Grandner said patients have been helped by combinations of psychotherapy and relaxation therapy.
Because of the nature of the study -- a "cross-sectional" survey -- the authors said they can't conclude that a cause-and-effect relationship exists between aging and sleep.
Vitiello did point out some methodology issues with the survey, such as an overall response rate of only 40 percent. And, because the study was landline based -- no cellphones -- he added that could affect participation rates among different age groups.
"The common knowledge is that sleep deteriorates with age," Grandner said. And, he added, many sleep-lab studies have shown "certain aspects of sleep get worse as you get older. Older people tend to take longer to fall asleep, they have more awakenings. A lot of the restorative and healing functions of sleep tend to happen less in older people.
"However, what we found [in the study] was that even if their sleep objectively might be worse, their experience of their sleep is better," he said. Part of the explanation may be that older people have other health problems that leave sleep issues lower on their radar. "Somebody who's much younger [might have] a much higher expectation of how they're going to sleep," he said.
It could also be that people in poor health -- who are more likely to have sleep problems -- are less likely to survive to older ages, he said.
For his part, Vitiello said, "If you're healthy, you're probably sleeping quite well, even into your 80s. So, if you see an older person who is having a lot of problems staying awake during the day, you shouldn't just excuse that as, 'Oh, that's just an old-people thing.' "
The U.S. National Institute on Aging has more on getting a good night's sleep.