David Mann started struggling with sleep in 2000. He had moved into an apartment near the front door of the building, and he attributed his frequent awakenings to hearing people coming and going at all hours. When he later moved into a house and the problems continued, he blamed his bedroom’s lack of darkening curtains. Then it was the nighttime disturbances of a new baby.
“One thing replaced the last thing as the explanation, and it kept going on and on,” he recalls.
Now, 20 years later, he still struggles to get an uninterrupted seven or eight hours of sleep most nights, despite taking a variety of over-the-counter sleep aids, participating in a sleep study, and seeing several sleep specialists.
Mann is far from alone. According to the Sleep Foundation, up to 30 percent of American adults suffer from chronic insomnia. That clinical diagnosis is based on specific symptoms: frequent difficulty falling or staying asleep, resulting in daytime impairment or distress.
“Insomnia comes from the three Ps,” explains Phyllis Zee, PhD, a Northwestern University circadian-health researcher and insomnia specialist. “A biological predisposition; a precipitating factor, such as a traumatic event or shift work, which causes short-term insomnia; and a perpetuating factor — attitudes and behaviors that make the insomnia chronic.”
Insomnia is often conflated with sleep deprivation, but there are important distinctions between them. Insomnia is chronic (at least three nights of impaired sleep per week for three months or longer) and occurs despite ample sleep opportunity.
It’s a daunting diagnosis, but identifying and addressing its root causes can help you start to put the issue to bed.
Sleep Quantity vs. Quality
We all know how important it is to get enough sleep, but equally critical is sleep quality. Sleep-medicine specialist W. Chris Winter, MD, author of The Sleep Solution, explains that slumber has three main phases: light, deep, and dream (or REM) sleep. If transitions to deep and REM sleep are disrupted, we may spend more time in light sleep, which is not as restorative.
“Sleep is like food — you can eat a lot and not feel healthy,” notes Winter. “You also need the right kind of food.” Some insomniacs may get “enough” sleep, but because the quality is poor, they wake up feeling as if they hadn’t dozed at all.
“Some people have a condition called heightened arousal,” explains Zee, “so even during sleep their brain doesn’t shut down. It’s a lighter sleep and they wake up more frequently, so they feel like they’re not sleeping soundly.”
Since sleep is critical to overall health, we may be motivated to do whatever we can to get those precious z’s, including turning to prescription medication. A July 2018 Consumer Reports survey found that nearly a third of people who complained of sleep problems had used a sleep drug in the past year. Of those using over-the-counter or prescription sleep aids, 60 percent reported side effects, such as drowsiness, confusion, or forgetfulness the next day.
“It is possible that medication-induced sleep does not provide the same restorative immune benefits as natural sleep,” writes sleep researcher Matthew Walker, PhD, in his book Why We Sleep.
What’s more, over-the-counter sleep drugs frequently contain sedating antihistamines that trigger dry mouth and constipation.
Prescription sleep aids have also been associated with health issues of their own, including impaired memory, headaches, and gastrointestinal issues.
Studies in mice suggest that benzodiazepines (used to treat insomnia as well as anxiety and alcohol withdrawal) may even increase susceptibility to infection by interfering with the signaling of the soothing neurotransmitter GABA (gamma-aminobutyric acid). Walker finds the correlation between sleep medication and infection risk particularly concerning for older adults, who use these prescriptions more than any other segment of the population.
Changing Sleep Rhythms
Our sleep patterns evolve as we age. While young children might need nine or 10 hours of sleep each day, older adults may require closer to seven.
“From the time we’re born until we die, there’s a slow loss of sleep need,” says Winter. “And there are periods when that reduction is accelerated, like between infancy and age 2, or during menopause.”
When older adults have trouble sleeping through the night, it may be due to shifts in circadian timing. As we age, our internal clocks release the sleep-signaling neurotransmitter melatonin earlier in the evening, which can lead to more frequent dozing off in front of the TV.
Our drive to sleep typically increases slowly through the day, building what’s known as “sleep pressure,” explains Walker. When that pressure is reduced by an early-evening catnap, it can be more difficult to fall asleep at bedtime or stay asleep during the night. And that regressed circadian clock also sounds the internal alarm earlier in the morning. “Add these things up, and a self-perpetuating cycle ensues,” he says.
One way to address this circadian shift is to get plenty of bright-light exposure in the late afternoon, delaying the evening release of melatonin. A 2007 study also found that taking melatonin helped older adult subjects (those over age 55) fall asleep more quickly and improved self-reported sleep quality and morning alertness.
Caffeine is a powerful stimulant, which means it can be tempting to reach for it in the morning after tossing and turning all night. But its stimulating properties make it a double-edged sword for insomniacs.
“We think that caffeine makes us more alert,” says Orfeu Buxton, PhD, a Penn State University professor of biobehavioral health. “It actually makes us more anxious and a little more alert, and the anxiety lasts longer than the alertness.”
Caffeine is also habit-forming and tolerance-inducing — meaning you’re likely to need increasing amounts to achieve the same buzz.
Along with the 24-hour circadian cycle that governs our internal clocks, internal sleep pressure helps regulate resting and wake times. Caffeine produces alertness by latching on to the brain’s adenosine receptors; adenosine is a sedating chemical that accumulates over the course of the day and builds sleep pressure.
When we block adenosine with caffeine, it mutes one of the body’s primary cues to ready itself for sleep. This is great when we want to be awake, but it often backfires.
Once the body has metabolized caffeine, backed-up adenosine rushes in, which can lead to the all too familiar caffeine crash. When we hit that wall, we often reach for more caffeine to power through the day.
But caffeine’s half-life can be five hours or more, so if we have coffee or tea at 4 p.m., as much as 50 percent of its caffeine may still be circulating in our brain tissue and blocking adenosine receptors at 9 p.m. This sets the stage for another sleepless night.
It’s a cycle of dependency familiar to many insomnia sufferers. “Caffeine, like sleeping pills, is an example of a temporary countermeasure to insomnia that might be OK in the short term but tends to point you in the wrong direction over time,” says Buxton. (For more on caffeine’s effects, see “The Pros and Cons of Caffeine”.)
Winding down in the evening with a nightcap has timeless appeal, but for those who suffer from insomnia, alcohol is likely to have the opposite effect. It works more like a prescription sedative, shutting down brain activity but not helping the body transition into restorative deep sleep.
“Alcohol doesn’t make a person fall asleep or stay asleep better,” says Winter. “It makes a person unconscious.”
What’s more, if you have a taste for sweet mixed drinks or sweet wine, the high sugar content can cause a quick boost in blood sugar that is usually followed by a crash. When your blood sugar plummets during sleep, it can trigger a surge of the stimulating neurotransmitter norepinephrine — which wakes you up. For those who were already nursing worries about whether or not they would sleep that night, the norepinephrine can aggravate that anxiety.