Sleep disorders are very common in the elderly, especially a pattern of early wakening and evening drowsiness, called Advanced Sleep Phase Syndrome. The American Psychiatric Association reported in 1990 that more than 50% of people over 65 have chronic sleep disturbance, and that approximately half of the prescriptions for medications such as benzodiazapines, used to treat sleep disorders, are written for elderly people. Unfortunately, these medications often have significant side effects for older people, including paradoxical responses and negative interactions with other medications. Even when these drugs provide some benefit, which they frequently do not, it is typically short-term - two weeks or less.
Research done at medical centers and universities worldwide since 1983 has demonstrated that light treatment, using the type of lightbox initially designed to treat Seasonal Affective Disorder (SAD), is a highly effective intervention for people suffering from many types of sleep disorders. As lightboxes have been improved it has become possible to achieve therapeutic results very rapidly.
Citation: M Terman et al. Journal of Biological Rhythms, 10: 2, 135-147, 1995
Studies in the US and Japan have shown that evening bright light treatment is an effective intervention for Alzheimer's patients. In 1992, researchers from Harvard Medical School, reported significant improvement in 8 out of 10 patients with severe "sundowning" (defined as a syndrome of recurring confusion in the late afternoon or early evening) after one week of treatment with only moderately bright light for two hours in the early evening. Light treatment stopped the late afternoon agitation, pacing, yelling and restlessness of these patients. Their sleep patterns also improved dramatically, with fewer nighttime awakenings and less daytime napping.
Citation: A Satlin et al. American Journal of Psychiatry, 149: 8; 1028-1032, 1992
In 1994, a Japanese research group observed the effects of light treatment in 14 geriatric inpatients with vascular dementia, using a control group of non-demented people of the same age. They found that four weeks of bright light treatment in the morning significantly increased sleep time (total sleep time and nighttime sleep) and diminished the behavioral disturbances (wandering, violent behavior, restlessness, etc.) of the inpatients.
Citation: MK Okawa et al. Acta Psychiatrica Scandinavica: 89: 1-7, 1994
Bright light provides therapeutic benefit in two ways. First, light is intrinsically activating and has an immediate and short-term effect on attention, mood and cognitive functioning. Second, bright light is the easiest and most natural way to set the body's biological clock, thereby treating the underlying sleep disorder of these patients. The master clock, located in the hypothalamus of the brain, consists of 6 proteins that switch genes on and off over a 24 hour cycle, coordinating all of our body's daily rhythms: the sleep/wake cycle, body temperature, blood pressure, and hormones. Natural daylight is called "the pacemaker of the body" because it the primary regulator of the biological clock.
Without a bright light signal in the morning, the biological clock tends to get deregulated, causing a variety of biological rhythm disorders. For example, most of us have experienced the acute distress and inconvenience of jet lag which results from traveling rapidly across several time zones, when our body clock cannot adapt as quickly as our plane can fly us to our destination. And workers in health facilities and factories are regularly subjected to sleep deprivation when they work long or variable shifts, which is known to put them at increased risk for job-related accidents. (Learn more about light therapy for jet lag and shift work.)
S.A.D., and its milder form, "winter blues", is a biological rhythm disorder. It is common at the latitudes where we live, because for several months each year the intensity of light is insufficient to set the biological clock. Dawn light in Boston on December 21 is literally hundreds of thousands of time weaker than dawn light on June 21, and the day is almost twice as short. Roughly one quarter of the population in New England suffer from this "atypical" mood disorder. The defining characteristics of SAD are "atypical" depressive symptoms: an increased desire for sleep, lethargy, carbohydrate cravings and, often, weight gain. SAD is a sleep disorder (Delayed Sleep Phase Syndrome) characterized by trouble getting up in the morning as the fall progresses. It is common in adolescents, who may tend to stay up later and later at night until the sleep wake cycle is almost reversed from what is considered normal. The recommended and most effective way to treat SAD is with twenty minutes of morning bright light daily using a lightbox.
The sleep disorders of the elderly- healthy or not - have many physical causes. Cataracts block the retina's ability to take in light. Clinical depression is all too common. The process of aging may in itself disrupt the smooth regulation of the biological clock. But as people age they tend to get dramatically less light exposure due to external factors, such as poor interior lighting, confinement due to illness, or restricted physical mobility. Fortunately, even moderate increases in the amount of light exposure can dramatically improve sleep, cognitive functioning and mood.
Light treatment is safe and there are no serious side effects. If it is not well tolerated, the solution is simple: decrease the intensity by sitting further from the lightbox, switch off some tubes (if possible), use it for a shorter time period, or turn it off. Light treatment has enormous potential for helping manage patients with dementia and for improving the sleep and quality of life for anyone whose ability to get outdoors is restricted.
As clinicians, we can allay fears about light treatment, help in dealing with resistance to using bright light or light hypersensitivity, and provide information about possible contraindications.