How effective are light boxes in staving off winter blues?

Tips for beating the seasonal blues are as numerous as the winter night is long. Light boxes, touted to “uplift people’s spirits” and “improve mood and energy,” offer a New-Agey-seeming solution to propel us into the cold as if it’s the first beautiful day of spring.

But can sitting in front of a light for a few minutes a day actually counteract the dreariest months?

(JOHN D MCHUGH/AGENCE FRANCE-PRESSE VIA GETTY IMAGES) - Light boxes use bright white fluorescent bulbs (or sometimes blue light) that reproduce some wavelengths of the sun’s light.

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Yes, in many cases. Light-box therapy has been shown to alleviate symptoms in people who suffer from seasonal affective disorder, or SAD. Symptoms of this form of depression — they can include lost interest in beloved activities, overeating, loss of energy, disrupted sleep cycles and feelings of hopelessness or guilt — typically appear in late fall or early winter and dissipate in spring.

Women are twice as likely as men to seek treatment for SAD, and those farther away from the equator are more likely to be diagnosed: About 11 percent of Mainers have a clinical SAD diagnosis, but only 2 percent of Floridians report the illness, according to Kathryn Roecklein, an assistant professor of psychology at the University of Pittsburgh.

One tool doctors use to treat SAD is light-box therapy. Light boxes use bright white fluorescent bulbs (or sometimes blue light) that reproduce some wavelengths of the sun’s light. They contain filters to block harmful UV rays and come in various shapes, sizes, light types and price points.

Scientists know that light hitting the retina can directly increase alertness and positive moods and can synchronize circadian rhythms, but they don’t know which of these actions is behind light-box therapy’s effectiveness.

Generally, doctors recommend sitting in front of a light box for 30 minutes each morning, the time when the treatment has been found to be most effective. Most light boxes emit 10,000 lux (a measure of illumination), though some inexpensive models crank out only 2,500 lux. A sunny day measures about 50,000 lux, while light in an indoor room typically measures no more than 400 lux.

Side effects are rare and minor, though those with diabetes and eye problems are at greater risk of eye damage, and some studies suggest an increased risk of manic episodes among those with bipolar disorder.

Light-box therapy typically alleviates symptoms of SAD within a week, but they return if a person stops regularly using the box. Studies show that roughly half to three-quarters of people with SAD report that their symptoms decrease when using light-box therapy. (By comparison, about half of people using antidepressants report a drop in symptoms.)

Doctors might also prescribe medication or use cognitive behavioral therapy tailored for SAD either in conjunction with or instead of light-box therapy. Unlike light-box therapy, cognitive behavioral therapy, which seeks to modify a person’s thought patterns to improve coping, has been found to last through several seasons, Roecklein says.

But what about those whose symptoms stop short of SAD but for whom winter doldrums make it extra difficult to go to the gym or haul themselves out of a warm bed? Light boxes can be effective, but it’s still best to consult a doctor before handing over your credit card. Timing, duration and intensity are all variables in light-box use, and Roecklein says those who try the therapy without first seeing a doctor may not understand how to make it work for them and conclude it isn’t effective.

As with your bedroom lamp and awful office lighting, a tanning bed is a terrible stand-in for a light box. Exposure to harmful UV rays, which aren’t filtered out as they are in most light boxes, greatly increases the risk of skin cancers. Also, as Roecklein points out, tanning-bed users cover their eyes with goggles, blocking what research shows is the pathway to alleviating SAD symptoms.

This is an edited version of a story that appeared in Slate.

 
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