Light therapy is exposure to sunlight (or, where necessary, synthetic lighting tuned to similar wavelengths). It can be used for management of several skin conditions. However, there are also several mental health benefits of light therapy, including regulating sleep cycles and easing winter depression, or seasonal affective disorder (SAD). More radical claims from alternative health practitioners suggest that light therapy may have other benefits as well, including treatment of depression.
When used for mental health purposes, light therapy often makes use of a device called a light box. This box allows a person to be exposed to a controlled amount of light, typically in a particular spectrum of wavelengths, such as those between blue and green. Philips, for example, manufactures special LED light panels which can be useful for light therapy.
The first use of light therapy was to manage circadian rhythm, or a person’s natural (but sometimes disrupted or abnormal) cycle of waking and sleeping. Timed exposure to bright lights, particularly directly after waking up, can be used to regulate when people wake up, helping sufferers of disorders such as delayed sleep phase syndrome or circadian rhythm sleep disorder, which causes people to have abnormal sleeping and wakeful periods. People with this disorder may be unable to fall asleep for most of the night, and once asleep, find that their normal sleep cycle takes them abnormally late into the day (such as noon, or later). Light therapy can simulate dawn lighting and try to “trick” the body into an altered sleep cycle.
In addition, medical researchers have confirmed that light therapy can be helpful in treating seasonal affective disorder (SAD). SAD is a type of depression related to seasonal change, in the northern hemisphere during the winter, when there is reduced sunlight. Very bright green or blue light, experienced in a controlled setting such as a lightbox, has been shown to assist in overcoming this depression. Although many may find this a strange remedy, even a “quack” cure, the evidence does show that light therapy is very effective. Moreover, it is hardly the strangest remedy for SAD – in the mid-20th century, for instance, houses in Canadian Arctic communities were all painted very bright colors in an attempt to cheer people up during the long, cold, dark winter months.
Alternative medicine practitioners have suggested there may be other mental health benefits of light therapy, as well. For instance, University of California psychiatrist Daniel Kripke has argued that people with other forms of depression, not just SAD, can benefit from light therapy. These claims are newer and, at least for the time being, less supported by clinical research.