SAN JUAN, P.R. – Sleep disorders become more common with increasing age, but effective behavioral and pharmacologic therapies are available, sleep experts said at the annual meeting of the American Association for Geriatric Psychiatry.
“Most older adults are not being treated for their insomnia, and most older adults won't get a diagnosis of insomnia,” despite the high prevalence of the disorder among this age group, said Dr. Phyllis C. Zee, medical director of the Sleep Disorders Center at Northwestern Memorial Hospital in Chicago.
There are several age-related changes in sleep architecture. The number of awakenings during sleep time increases, especially in the early morning. The amount of light sleep is increased, and the amount of deep sleep is decreased. There also is a decrease in REM sleep, said Dr. Zee, who also serves as a professor of neurology, neurobiology, and physiology at Northwestern University, Chicago.
Two major mechanisms regulate sleep in humans: the homeostatic drive and the circadian drive. Control of the circadian system resides in the suprachiasmatic nucleus, which provides timing information for physiologic, hormonal, and behavioral rhythms.
Several changes in circadian sleep rhythms come with age. The amplitude of circadian rhythms decreases, while the variability of circadian rhythms increases. “There's also a very noticeable advance in [the] phase of circadian rhythms,” Dr. Zee said. Severe disruptions of the sleep/wake cycle often occur among older adults with dementia and in those in nursing homes.
The homeostatic drive for sleep depends on accumulating enough hours of wakefulness to trigger sleep, and this drive is reset during sleep. It's thought that the homeostatic drive is regulated by the ventrolateral preoptic area of the hypothalamus.
It's important to understand these sleep mechanisms when treating sleep disorders. “There is not a thing you can do to make yourself go to sleep. … What you can do is arrange the circumstances and timing of your wakefulness in a way that makes the involuntary process of sleep more likely,” said Dr. Daniel J. Buysse, medical director of the sleep evaluation center at the Western Psychiatric Institute and Clinic of the University of Pittsburgh
“Sleep hygiene education is without a doubt the most widely employed and … the least efficacious” of the behavioral treatments for insomnia, Dr. Buysse said. Most patients are already aware of many of the suggestions for good sleep hygiene, such as avoiding caffeine before bed.
To understand the patient's sleep habits, behavioral therapists start by asking about average time in bed, average rise time, total time in bed, time to fall asleep, amount of wakefulness during the night, and total wake time.
Using this information, they calculate the average amount of total sleep (total time in bed minus total wake time). For most individuals with insomnia, there is a discrepancy between the total amount of sleep that they get and the total amount of time they spend in bed, said Dr. Buysse, also a professor of psychiatry at the University of Pittsburgh.
Several common elements are involved in behavioral treatments for insomnia: monitoring sleep-wake patterns, reinforcing associations between bed and sleep, limiting awake time in bed, establishing a regular sleep-wake schedule, and using voluntary behavior to influence the involuntary physiologic process of sleep.
To help patients minimize insomnia, he advised doing the following:
▸ Restrict time in bed.
▸ Establish a regular wake time.
▸ Go to bed only when sleepy.
▸ Stay in bed only when asleep.
By putting these suggestions into practice, a patient's total time in bed should be equal to the total sleep time, plus about 30 minutes, Dr. Buysse said. He and his colleagues have tested the effect of these changes in sleep behavior on sleep quality in a small study of 13 patients who made these changes, compared with 12 subjects who received basic sleep information. Those in the active treatment group showed a significant improvement in sleep quality, while those in the control group showed no change.
In addition, those in the active treatment group also showed improvement in sleep latency–how long it takes to fall asleep–and waking after sleep onset, while controls did not.
Pharmacologic management of acute and chronic insomnia includes benzodiazepine receptor agonists, melatonin, melatonin receptor agonists, and antidepressants.
In 2005, a National Institutes of Health state-of-the-science panel noted that hypnotics are efficacious in the short-term treatment of insomnia. However, with the exception of eszopiclone, the benefits of these agents have not been studied for long-term use.
Zaleplon (Sonata), zolpidem (Ambien), and eszopiclone (Lunesta)–benzodiazepine receptor agonists–are all indicated for the treatment of insomnia.