Let the Sunshine In: Sleep Disorders & Dementia

Published In Mental Health & Well-Being

Let’s talk about sunshine and the incredible role that it plays in our well-being. Older adults, particularly nursing home residents, tend to get less of it than younger adults, but everyone needs it and many of us don’t get enough of it.

While sun exposure has its risks, such as skin cancer, it also provides tremendous benefits. It spurs the body’s production of vitamin D, which is essential for good health, and it can help forestall SAD, or seasonal affective disorder. Sunlight also plays a critical role in the workings of our biological rhythms. While some animals are nocturnal creatures (meaning “most active at night”), humans are not. We are geared to be diurnal – more alert during the daylight hours and at rest when the sun has set. We mess with this evolutionary arrangement at our peril. Just ask anyone who has ever worked the graveyard shift, as many of my nursing colleagues do. Staying awake all night and trying to get restful sleep during the day on a consistent basis leads to a type of sleep disorder specific to these workers – “shift-work sleep disorder.”

The Anatomical and Behavioral Underpinnings of Sleep

The human brain contains specialized anatomical structures that respond to sunlight and regulate our sleep-wake cycles. One important piece of our anatomy is the pineal gland, a small, pinecone-shaped rudimentary photoreceptor nestled deep in the brainstem. As sunlight hits our eyes, it passes through brain structures and activates the pineal gland, which then secretes melatonin into the bloodstream in varying quantities. Melatonin helps to tell you when to be sleepy and when to be awake. But, as I learned years ago as an intern, there are other important ways that we, as humans, regulate our sleep-wake cycles. I recall being told, more than once, that “sleep is one of the most behaviorally conditioned physiological functions there is.”

How is this so? Consider the idea of zeitgerbers (literally “timekeeper” in German), a term I picked up rotating through the sleep medicine clinic. In addition to the direct chemical influence of sunlight on melatonin production, which directly affects our sleep-wake cycles, we are also attuned to our environment, which helps us to know when to sleep and when to be awake. These “zeitgerbers” include:

  • The position of hands on the clock
  • The crowing of a rooster
  • The smell of coffee in the morning
  • The position of the sun in the sky
  • The length of shadows

Generally speaking, in otherwise-normal adults (and sometimes in children), sleep disorders tend to happen when we don’t listen to the natural, physiological rhythms of our bodies. People suffering from depression or anxiety often have trouble responding to these rhythms, and suffer from sleep disruptions as a result. Alcohol is a classic way to disturb sleep and often one of the first areas of inquiry for clinicians quizzing patients who present with sleep problems. Caffeine is also a culprit, along with a number of drugs.

Sleep Disruptions Associated with Dementia

Dementia can be a huge contributor to sleep disorders in older adults, as any caregiver can tell you. People with dementia sometimes behave as if they’re shift-workers! They sleep during the day and they’re up all night. They can have what almost resembles a sleep attack (a feature of another sleep disorder called narcolepsy) where they nod off almost without warning during the day.

And then there’s the sundowning syndrome, or, as it’s alternatively called, “nocturnal confusion.” That’s when care recipients with dementia get more anxious, agitated, and confused as day becomes evening. One of my first clinical cases as a trainee in geropsychology involved a very nice middle-aged woman who was taking care of her father, who was in his 80s and had Alzheimer’s disease. Invariably, every evening, he would get restless and try getting up from the lounge chair where he typically spent most of his day watching TV, and then he would ask his daughter when he can “go home” (which, to him, meant his childhood home). This was very trying for the daughter who would be up with her father until the early hours of the following morning, and then the two of them would sleep through much of the next day.

Is it possible that sundowning and shift-work sleep disorder are really the same thing, and that they’re both circadian-rhythm sleep disorders? In other words, maybe the reason why the gentleman in the case above got more active at night wasn’t simply just because demented people act out, but rather that he was unable either to respond to his external cues or zeitgerbers (such as the clock on the wall), or to respond to his own internal cues. Possibly his brain was less sensitive to internal melatonin production or was having more trouble producing it.

Sleep Disorder Treatments

This gets us to the question of how we treat sundowning, particularly if it is a special concern for people with dementia. First, let’s talk about what doesn’t work – sleep medications. The most common would be the benzodiazepine-related class of medications (valium is the most well-known), but specialists avoid these because older adults with dementia are prone to confusion and falls and these medications would simply make the problem worse. In fact, most sleep medications tend to increase confusion in older adults, even over the counter ones like Benadryl, so these are not good ways to treat nighttime agitation and confusion associated with sundowning.

Instead, we recommend:

  • Exercise. The ideal would be to offer the care recipient some physical activity a couple of hours before bedtime to “tire them out” before the bedtime routine begins. But it is important not to exert them too much, which tends to “rev them up” so they are too awake – not the intended effect!
  • Food. Offer the care recipient a small, carbohydrate-laden snack prior to bed, but nothing too large.
  • Warm bath / shower. Time it a couple of hours before the intended bedtime. A warm bath or shower right at bedtime can raise body temperature to a point where they are too wakeful. Again, not the intended effect.
  • Avoid involved or stressful routines right before bed. If it’s a stressful routine getting your loved one dressed in pajamas, teeth brushed, or bathed right before bedtime, maybe you can move some of those things to earlier in the evening or late afternoon. Or perhaps it’s OK if your loved one doesn’t wear pajamas to bed!
  • Make sure the home is well lighted. Some have theorized that the reason why older adults get more agitated and anxious at night is because the shadows get long and familiar surroundings begin to look alien – hence my example of the older adult asking to “go home” even though he was already home. Some caregivers even hire lighting consultants to make sure that illumination stays constant in the home, even as the sun sets.
  • Warm milk, soft music, and massage. Focus on the familiar and the soothing. These things never hurt.

Then there are treatments that are more off-the-beaten-path or downright experimental. There is some evidence that SSRIs and the non-benzodiazepine based sleep medication Trazadone may be helpful for sleep problems similar to what plagues sundowners, so they may be helpful for sleep issues in dementia – but again, these are psychoactive medications so they come with side effects that can lead to increased risk of falls and confusion

Finally, since sundowning simply may be a type of circadian-rhythm sleep disorder, two obvious interventions need review: light therapy and melatonin supplementation.

The idea behind light therapy is obvious and the approach is straightforward. Since regular sunlight exposure tends to regularize the diurnal sleep-wake cycle, the idea is to expose subjects to regular doses of either natural sunlight by taking them outside in the morning hours, or by exposing them to full spectrum light via specialized lightbox equipment. Note that this is different from the lights in your home, which are not full-spectrum. I have tried lightbox therapy with patients and found it difficult to get an older adult with dementia, who has difficulty concentrating and following directions, to sit still for a ½ hour a day in front of a sunlamp to get the proper dosage. It’s challenging enough for intact younger people!

Melatonin is more interesting. When I was a rotating in a sleep lab, I asked why melatonin wasn’t routinely recommended for patients with circadian rhythm problems and was told that it was so difficult to time the dose that it was easier to go with treatments like antidepressants and lightbox therapy.

Recently, attitudes have changed and melatonin looks a lot more promising as a therapy, particularly for sundowning Alzheimer’s patients – and even, potentially, as a treatment for Alzheimer’s dementia itself. Although melatonin is available at health food stores, it is a psychoactive product and may have side effects, particularly if taken by a person with dementia who also may be taking other medications. Please, consult your loved one’s physician before trying melatonin as a sleep aid.

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