Compared to many other treatments, bright light therapy is simple, inexpensive, and easy for patients to administer themselves. It is safe, even for pregnant women and children. More and more research is being done to show the positive affects of light therapy for a wide range of symptoms and conditions.
Sundowning describes the increased agitation and confusion that occurs for Alzheimer's sufferers in the late afternoon and evening and they are often found up in the middle of the night. It’s possible that sundowning occurs because the disease begins to affect the parts of the brain that control the circadian rhythms, the body clock and the sleep-wake cycle.
The combination of damaged nerve pathways and normal ageing eyesight means that usual levels of light are not sufficient to signal that it is daytime. The internal body clock goes off kilter, affecting the wake-up and sleep functions in the body.
Studies show that better and brighter lighting can help improve sundowning behaviour and reduce sleep/wake disturbances. Morning sessions in front of a bright light, for example 2,500 lux lights for an hour, can be particularly effective. Improving overall lighting conditions can also have positive effects. There is some evidence to show that dawn and dusk simulation, for example using
For more information, read the guide to light therapy and Alzheimer's disease.
Studies show that bright light can have positive effects in treating patients who are depressed, even if they do not have SAD. Major depression sufferers treated with blue-white bright light therapy showed reduced depression scores, better sleep and waking and general mood. Their levels of melatonin (the hormone needed for sleep) and cortisol (one that promotes activity) shifted to be more in line with healthy sleep/wake patterns. Some of the benefits lasted even after the trial ended.
These and other studies suggest there is a growing place for light therapy as a treatment for non-seasonal depression, particularly for patients who do not want to take anti-depressant drugs.
Overeating: many people with seasonal affective disorder tend to overeat in the darker winter months or experience food cravings, especially for carbohydrates. Studies have found that light therapy makes a difference to food intake in winter. SAD sufferers who were treated with light during the darker months ate the same amount of carbohydrates as they did in the summer.
Bulimia: research has found that bulimia nervosa can often be seasonal, with sufferers improving in spring and relapsing in winter. One study in Japan found that 40% of bulimia patients suffered from SAD. Researchers suggested that as SAD symptoms can be alleviated by light therapy, then bulimia sufferers may also be helped by light therapy, as it may reduce overeating and food cravings. A trial with a patient with seasonal bulimia found this to be the case.
Anorexia: In another study, anorexia sufferers who received light therapy saw their depression scores improve significantly and increased body mass index sooner than those who were not treated with light.
Jet lag refers to the symptoms that we experience after rapid travel across time zones. The body clock, that drives daily rhythms in our physiology and behaviour, cannot instantaneously shift to the new destination time. The main symptoms are difficulty falling and staying asleep, poor quality sleep, gastrointestinal disturbances, and mental fogginess when awake. The causes are both fatigue and a misaligned body clock.
Light is the most powerful stimulus for resetting the body clock. Exposure to light before and after a flight is critical in determining how long it takes to get over jet lag. Bright light also has instant, short-term effects. It shifts your body clock, while simultaneously enhancing your alertness and mood.
The bright lights shown here are useful before and after your journey though Zest is the only one designed for use when you travel. It's small enough to be used before, during and after your journey, and powerful enough (2,000 lux at 50cm) to deliver the light that will realign your body clock.
Researchers have discovered that bright light therapy as part of post-operative care can adjust the sleep/wake cycle of patients and improve recovery in the days after surgery. Recovering patients exposed to bright light in the days after surgery experienced a quicker return to normal in their co-ordination and concentration. They also tended to show lower levels of autonomic activity and reduced physical activity, which suggests that convalescence was more comfortable, an important factor in the first few days of post-operative recovery.
Post-traumatic stress disorder
Research suggests that light therapy can help reduce post-traumatic stress disorder (PTSD) by regulating and improving sleep patterns. One of the problems of PTSD is a disrupted sleep cycle, playing a precipitating and perpetuating role. In one study, soldiers suffering PTSD who were exposed to 10,000 lux lights for 30 minutes a day showed significant improvements in their sleep cycles, and received beneficial effects on the severity of their disorder.