What is light therapy?

Indications and Procedures

Light therapy, or phototherapy, treats a variety of disorders. By exposing individuals to different kinds of light (for example, monochromatic, polychromatic, ultraviolet), symptoms can often be delayed, reduced, and eradicated. Immunological, neurotransmitter, and neuroendocrine systems play key roles in response to this type of treatment.

Best known in psychiatry, light therapy serves as a treatment for seasonal affective disorder
(SAD), or winter depression; bulimia nervosa; sleep disorders; and “sundowner’s syndrome,” the late afternoon confusion and agitation sometimes accompanying Alzheimer’s disease. Shift workers can also experience difficulties related to light exposure, and light therapies may provide some relief. Reduced environmental light is a factor in the etiology, onset, or maintenance of these problems. Thus, treatment involves exposing individuals to bright, full-spectrum light for specific time periods. Duration of exposure and light intensity vary by the disorder and the individual treated.

In dermatology and oncology, light therapy treats psoriasis, skin
ulcers, tumors, and esophageal cancers. The type of light and the intensities used, however, vary considerably from those applied for the treatment of psychiatric disorders.

Uses and Complications

The side effects of light therapy are best documented in psychiatry: insomnia, mania, and (less frequently) morning hot flashes have been noted. Persons with other sensitivity to light, such as those prone to migraines, may also need to exercise caution with light therapy in order to avoid undesirable effects. Careful monitoring by medical providers of the patient’s response to treatment is necessary. Additionally, professionals advise morning administrations of light therapy.

Users of light therapy must also be cautioned to adhere closely to recommended doses and intensity of exposure to light. Use of light outside prescribed parameters may be damaging to the eyes.

Light therapy is not effective universally; some patients may experience no improvement. For seasonal affective disorder, evidence suggests that younger individuals whose depression involves weight gain and increased sleep may be most likely to respond to treatment. For psoriasis, complementary treatments, such as psychotherapy, may facilitate a response to treatment.

Perspective and Prospects

Light and dark cycles are a biological reality; thus, it is no surprise that light affects physical, emotional, and mental well-being. As the interest in noninvasive interventions increases, the attention given to environmental treatments such as light therapy is likely to increase as well. Recent developments in the use of light therapy for sleep and behavioral disorders are fueling clinical, research, consumer, and other business interests in this procedure. Experimentation with different frequencies or colors of light, doses, intensities, and sites on the body for the application of light are ongoing and likely to increase the diversity of uses for this type of treatment. Additionally, applications of light-based interventions in the workplace and elsewhere may prove useful in preventing disorders related to light deprivation and in helping to affect productivity, directly and indirectly.

Bibliography

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"Is Phototherapy Right for Your Psoriasis?" PsoriasisNet. American Academy of Dermatology, Jan. 2010.

Jacobs, Jennifer, ed. The Encyclopedia of Alternative Medicine: A Complete Family Guide to Complementary Therapies. Rev. ed. Boston: Journey Editions, 1997.

Kastner, Mark, and Hugh Burroughs. Alternative Healing: The Complete A-Z Guide to over 160 Different Alternative Therapies. New York: Henry Holt, 1996.

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Rosenthal, Norman E. Winter Blues: Everything You Need to Know to Beat Seasonal Affective Disorder. 4th ed. New York: Guilfod Press, 2013.

Safer, Diane A., and Michael Woods. "Phototherapy." Health Library, Nov. 26, 2012.