Clinically defined insomnia occurs in about 10% of the population of the United States, and more frequently it is women who bring the complaint to their doctor’s attention, researchers suggest.
“The reasons for that are not very well understood,” says Russell Rosenberg, PhD, chief science offer and chief executive officer of NeuroTrials Research of Atlanta, “but women are about 1.5 times more likely than men to have insomnia.”
“Clearly women have more insomnia,” agrees Steven Feinsilver, MD, director of the Center for Sleep Medicine at Lenox Hill Hospital and professor of medicine at Hofstra Northwell School of Medicine in New York City. “Part of it may be because women are more likely to go to doctors that men. It has been blamed on hormones.
“A lot of women complain about insomnia during menopause,” Dr. Feinsilver says, “but even women who are menstruating often complain of insomnia. Also, anxiety and depression are both more common among women, and anxiety and depression are more frequently linked with insomnia.”
The elderly — depending upon how that term is defined — also tend to have more insomnia complaints, the researchers said. “It is hard to even know what is normal when considering insomnia in the elderly,” Dr. Feinsilver says. “It may well be that as you get older, you need less sleep. It is pretty clear that older people do get less sleep and wake up more frequently at night.”
The definition of elderly is usually considered to be over age 65, but it really depends upon how old the person is who is defining what elderly is, Dr. Feinsilver says. “I’m 68, and I once rejected a paper for a journal because it put the elderly cutoff at 60, and I said, ‘Nah, 60 is too young.’ Most people consider 65 as the cutoff for elderly, but then there is something called the ‘old old’, for which the cutoff is 80.
“The problem in doing research on anything in the elderly is finding people in that age group that are completely healthy,” he says. “So many people who are older are on prescription medicines and have so many other things going on.”
And, Dr. Rosenberg adds, “As we grow older, we get more physical and mental disorders that might impact sleep. Older adults do tend to sleep less at night, but they do nap more. So their total sleep times doesn’t seem to change much as they age.
“The need for sleep does not decrease but there is less ability to sustain long periods of sleep at night,” he says. “There are people who say that as you age, you just have to live with getting less sleep at night and feeling sleepy during the day. That is really a fallacy. If you are not sleeping well and you are an older adult, you need to seek help for that.”
“Why elderly don’t get more sleep or need more sleep is a hard question,” Dr. Feinsilver says. “There have been some studies that have looked at this. There are changes in the brain as we get older that affect the stages of sleep. Sleep occurs in several stages, and non-REM Stage 3 slow wave sleep appears to be the really good stuff. It turns out that almost all the hormones that your body secretes, it secretes in slow wave sleep. Maybe as we age, we don’t need that much in the way of hormones.”
Dr. Feinsilver also said that environment is a major factor in avoiding insomnia. “Humans are designed to sleep in caves where it is dark, cold, and quiet,” he says. “Those are all really important and a lot of people, depending upon where they live, just don’t have a dark, quiet, cold environment.
“Light is also really important, especially among the elderly. One of the theories about the problems with elderly sleep is that we become less light sensitive as we sleep — a lot has to do with cataracts — so the effects of light might not be as strong in the elderly,” he says.
“There was a study several years ago that looked at people who lived near airports, and every time an airplane went over you could see little changes in the brain waves during sleep, even though the people who lived near the airport didn’t think they were bothered at all,” Dr. Feinsilver says.
“Other than aging and being female, the other major risk factors for insomnia are related to other conditions,” says Jennifer Martin, PhD, a clinical psychologist, professor of medicine in the David Geffen School of Medicine at the University of California at Los Angeles. “People with depression are more likely to develop insomnia, for example. In most cases, insomnia may initially be caused by other clinical disorder, but after that disorder is resolved and insomnia continues for 3 months or more, it’s unlikely to simply go away on its own.”
Dr. Feinsilver concurs. “There are all sorts of medical things, obviously, that can cause or contribute to insomnia,” he says. “Anything that hurts doesn’t necessarily go away when you sleep and makes it not possible to sleep well.
“Heart disease and lung disease are bad for sleep,” he says. “Nobody who is short of breath lies down. If you get short of breath, you sit up, because your lungs work better that way. People with asthma have a worse time at night.
“And then there are sleep illnesses, such as sleep apnea, which is not that unusual with insomnia,” Dr. Feinsilver says. “As many as 30% of people with sleep apnea present with insomnia. These are people who snore at night, get up frequently, and then are sleepy during the day.”
“It is not normal to be sleepy in the daytime,” says Dr. Rosenberg. “The whole idea of getting treatment is that so you can sleep better so you feel better during the daytime. If you are feeling sleepy during the daytime, that is a good signal to go see a health care provider.”
About 7% to 10% of people meet the diagnostic criteria for insomnia, he says: Having trouble falling asleep or staying asleep for at least three days a week and persisting for at least three months, paired with having a disturbed quality of life because you are feeling sleepy in the daytime. “About 30% of people exhibit insomnia symptoms,” Dr. Rosenberg said.
“Insomnia has an impact on productivity in the workplace and in health care resource utilization,” he says. “People with insomnia, where they seek treatment for insomnia directly, still utilize health resources more than people who do not have insomnia. Work productivity is also lower, and there is more absenteeism.”
Dr. Feinsilver cautions, “Pills can be useful — a lot of it is placebo anyway — but you don’t want anything that makes you feel worse the next day. The point of sleep is to be awake the next day.
“Sleep is complicated,” he says. “You want it to be normal sleep and not just seven hours of unconsciousness.”
Rosenberg disclosed that he and his research organization consult for all the companies that work on insomnia issues. Martin and Feinsilver disclosed no relevant relationships with industry.
Source: Various telephone interviews.