By Maureen Williams, ND
Healthnotes Newswire (October 4, 2007)—If you become depressed in the dark winter months, a daily dose of light may help. New research suggests that easing seasonal depression through light therapy could be easier than previously thought, thanks to smaller and more efficient light-producing devices.
People with seasonal affective disorder (SAD) start noticing their mood turning toward sadness and depression in the fall when the hours of sunlight shorten. In northern climes, SAD is more common because the angle of the winter sun is especially low, nights are exceptionally long, and the winter is longer.
Bright light therapy typically involves sitting in front of a light box that emits 5,000 to 10,000 lux for 30 to 60 minutes every morning. Performed in this way, light therapy has been found to be as effective as fluoxetine (Prozac) in relieving SAD. But light boxes are cumbersome and use a lot of electricity, leading some researchers to try designs using light-emitting diodes (LEDs) instead.
LEDs are smaller, lighter, and more energy-efficient than the incandescent and fluorescent light bulbs used in conventional light boxes. They are also able to emit specific light wavelengths in high concentration, while incandescent and fluorescent lights emit the full spectrum of visible light. Because light-sensitive rhythms in humans are most responsive to short-wavelength light, LED devices that emit this spectrum might not need to be as bright as conventional light boxes.
The latest study, published in BioMed Central Psychiatry, used a device called a “Litebook” (produced by the Litebook Company Ltd., Alberta, Canada), which is made with 60 LEDs producing 1,350 lux. The 26 people with SAD who participated in the study were randomly assigned to light therapy or placebo. Those in the light therapy group were instructed to sit facing the device at a distance of 20 inches for 30 minutes every morning; those in the placebo group were given negative ion generators—devices that have been shown to help with SAD—that were disabled and therefore not expected to have any effect.
After four weeks of treatment, about 57% of the Litebook users had no SAD symptoms, compared with 11% in the placebo group. In addition, the average scores on tests used to measure SAD symptoms improved more in the light therapy group than in the placebo group.
“The results of this pilot study suggest that 30 minutes of daily exposure to the Litebook LED device is efficacious in the treatment of SAD,” the study’s authors concluded. “A more convenient form of light therapy might lead to increased use of light for SAD.” This may be the case especially if future studies comparing LED devices with conventional light boxes find them similarly effective.
(BMC Psychiatry 2007;online publication)
Maureen Williams, ND, received her bachelor’s degree from the University of Pennsylvania and her Doctorate of Naturopathic Medicine from Bastyr University in Seattle, WA. She has a private practice in Quechee, VT, and does extensive work with traditional herbal medicine in Guatemala and Honduras. Dr. Williams is a regular contributor to Healthnotes Newswire.
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