Visiting day rooms in many long-term care facilities can be a daunting experience for the uninitiated. Residents are often slumped over in their chairs, napping while games or other activities take place around them. A short while later these same residents may be awake and active, only to nod off again a few minutes later. Conventional wisdom tells us that this is what happens as we age; however, the scientific literature tells a different story. Frequent napping is a disorder, which in a sense is good news, because it means that there’s something we can do about it. Evidence from clinical trials indicates that by providing a regular pattern of light and darkness, we can restore a more stable wake/sleep rhythm that aligns better with the natural day/night cycle. The potential benefits of this include improved daytime alertness and nighttime sleep as well as positive effects on cognition and mood.
Each day we eat and process nutrients, and sleep and repair our systems, with our bodies creating a cascade of proteins and hormones in an orchestrated sequence of events that control our physiology, biochemistry, and behavior. Since most of these processes occur on a daily basis, we call them circadian (taken from the Latin words circa, meaning “close to,” and dia, meaning “day”). Timing is key to maintaining order among circadian rhythms so that potentially conflicting processes are scheduled at different times, and complementary processes occur together or sequentially.
An example of this is the way cortisol and melatonin rise and fall in counterpoint to each other. Cortisol is a hormone that promotes alertness and typically peaks in the morning, while the hormone melatonin causes drowsiness and plays a role in sleep. What keeps these rhythms in sync is the natural light/dark cycle that drives all life on earth. The general truth of this is well established, but what’s new is an understanding of how light and darkness affect us, which gives us tools to use in creating a built environment that supports our health and well-being.
Shedding light
Recent research tells us that light at the eye not only causes a sensation in the part of the brain where visual images are produced but signals are also sent to a control center in another part of the brain that orchestrates our circadian rhythms. This control center is often called our “circadian clock.” This clock tends to run longer than 24 hours, and in our natural state, the light/dark cycle resets our clock each day so we’re in sync with the natural world.
Residents in long-term care, however, spend their days in the artificial built environment, with little access to bright light. Indoor light levels are quite low compared to sunlight, and lights are often left on at night so caregivers can work. Without a clear signal of daytime and denied darkness at night, the circadian clock can’t tell day from night, and disruption can occur.
Symptoms of circadian disruption include napping during the day, periods of wakefulness at night, being hungry at odd times, depression, and a loss of cognitive ability. Evidence from clinical trials indicates that by providing bright light during the day and darkness at night, we can mitigate these symptoms.
One example of this is found in a rigorous research project conducted by the Netherlands Institute for Neuroscience, which shows that increasing light levels to 100 footcandles at the eye in group care facilities reduced symptoms of disturbed cognition and improved mood, behavior, functional abilities, and sleep.
Depression is a major issue for residents in healthcare facilities, and light exposure can be an effective treatment. Dr. Ritsaert Lieverse was the lead author of a 2011 study published in the Archives of General Psychiatry that looked at bright light therapy to treat major depressive disorder in elderly patients. The study reported improvements to mood, enhanced sleep efficiency, and better outcomes in measures of hormonal synthesis.
In 2003, Sonia Ancoli-Israel, PhD, University of California San Diego, studied the effect of light on dementia patients. The published article concludes with this statement: “If results of this study are combined with results of the previous studies done on the effect of light on rhythms and sleep in dementia, the overall conclusion would be that increasing light exposure throughout the day and evening is likely to have the most beneficial effect on sleep and on circadian rhythms in patients with dementia. Increasing bright light exposure for patients with Alzheimer’s disease might even postpone institutionalization. In addition, it would behoove nursing homes to consider increasing ambient light in multipurpose rooms, where patients often spend much of their days. This, in combination with other behavioral therapies, might be the most efficient approach for improving sleep and circadian activity rhythms in this population.”
In putting the above trials together, the researchers made a number of informed choices that were grounded in knowledge about how people respond to light and darkness. Using design considerations developed from this literature, we can create a lighting environment that will help residents to get back to a more normal circadian rhythm.
Designing light and dark
Quantity and color are the prime considerations when it comes to lighting design in long-term care environments, along with controlling the timing of exposure. Daylight provides the natural quantity and color of light for all living things, but residents often spend their days indoors and don’t have access to the outdoors. The best solution is to design a building with skylights or daylight monitors to provide a high volume of natural light indoors. If the source must be electric light, bright light should be provided by a glare-free source such as a two-lamp fluorescent cove or a well-shielded pendant.
The color of light is also important since the response of the circadian system peaks in a narrow band of light in the blue range of the color spectrum. In order to be sure that the lamps we’re using include this part of the spectrum, we need to dig into the technical specifications published by lamp manufacturers (see resources box for more). In general, lamps that are cool white create more light in the blue part of the spectrum than warm white lamps. Locate the bright light system in high-activity areas where residents are likely to spend a good deal of time so that their circadian clock gets a daily dose of bright light.
Designing for darkness is just as important as designing for light. Working with caregivers, a darkness protocol should be created to help preserve a dark environment in bedrooms and bathrooms at night to ensure the circadian system will get the signal it needs to begin and sustain dark-induced functions. Nighttime lighting in the bedroom should include steplights activated by motion sensors so residents can find their way to the bathroom without switching on overhead lights. Caregivers can also use the steplights to check on residents, using room lights only if needed.
The bottom line
By creating a regular pattern of bright light and real darkness, the environments we create can promote more robust and stable circadian rhythms. The benefits of a stable circadian rhythm include longer and more restful sleep at night, and improved alertness and cognition during the day. Clinical trials using light to treat elderly patients have demonstrated this effect along with reduced aggression and reduced need for medication. These improved outcomes for residents also have implications for staff and the bottom line.
It’s easier and less stressful to care for a patient that is alert and responsive than one who’s difficult to communicate with. Patients suffering from Alzheimer’s often wake during the night and wander from their beds, which requires supervision from caregivers. The risk of falls is also higher at night. However, if patients are asleep for longer periods during the night, caregivers’ workloads are reduced, as is the risk of falls. And reducing the risk of falls pays real dividends by avoiding potential liability. Improved mood could also have an effect on cost: If patients experience fewer aggressive episodes, the risk of injury to themselves and to staff is reduced, lessening the cost of care by avoiding staff sick leave and liability.
While all of this makes good logical sense, there aren’t yet solid numbers to back it up, which presents an opportunity. In fact, efforts are underway to quantify these potential benefits through research in real-world situations.
Michael David White, EDAC, LC, LEED AP, is a senior lighting designer at Schuler Shook (Minneapolis). His current focus is evidence-based architectural lighting for a variety of project types including long-term care facilities. He can be reached at [email protected].
References
- Increased Light Exposure Consolidates Sleep and Strengthens Circadian Rhythms in Severe Alzheimer’s Disease Patients. Ancoli-Israel, S., Gehrman, P., Martin, J. L., Shochat, T., Marler, M., Corey-Bloom, J., & Levi, L. Behavioral Sleep Medicine, 1(1), 22–36. doi:10.1207/S15402010BSM0101_4
- Bright light treatment in elderly patients with nonseasonal major depressive disorder: a randomized placebo-controlled trial. Lieverse, R., Van Someren, E. J. W., Nielen, M., Uitdehaag, B. M. J., Smit, J. H., & Hoogendijk, W. J. G. Archives of General Psychiatry, 68(1), 61.
- Effect of bright light and melatonin on cognitive and noncognitive function in elderly residents of group care facilities. Riemersma-van der Lek, R. F., Swaab, D. F., Twisk, J., Hol, E. M., Hoogendijk, W. J. G., & Van Someren, E. J. W. JAMA: The Journal of the American Medical Association, 299(22), 2642–2655.
- Senior Living Environments: Evidence-Based Lighting Design Strategies. White, M. D., Ancoli-Israel, S., & Wilson, R. R. HERD-Fall-2013.
- Brainard, G. C., Hanifin, J. P., Greeson, J. M., Byrne, B., Glickman, G., Gerner, E., & Rollag, M. D. (2001). Action Spectrum for Melatonin Regulation in Humans: Evidence for a Novel Circadian Photoreceptor. The Journal of Neuroscience, 21(16), 6405–6412.
- For an in-depth discussion on color of light and circadian response: www.lrc.rpi.edu/programs/lightHealth/pdf/spectralsensitivity.pdf
