Q. Do light boxes for seasonal affective disorder (the "winter blues") actually work?

A. About 5 percent of people in the U. S. suffer from seasonal affective disorder, or SAD, the temporary depression that develops in autumn and winter, most often in northern regions, according to the American Academy of Family Physicians.

Research suggests that bright-light therapy helps about 50 percent of people with the disorder, which is linked to the declining hours of sunlight that come with winter.

Some symptoms are similar to those associated with other types of depression: sadness, fatigue, excessive sleepiness, withdrawing socially, and trouble concentrating. But SAD sufferers also tend to move slowly, crave carbohydrates, and gain weight.  

If you have SAD and it’s relatively mild, relief might be as simple as a good long walk to start your day, says Marvin M. Lipman, M.D., Consumer Reports chief medical adviser. And several studies show that doing 60 minutes of outdoor exercise in the morning can be a big boost for people with SAD.

Otherwise, consider trying bright-light therapy, which involves sitting in front of a special lamp that produces up to 10,000 lux of light for about a half-hour every day during the darkest months of the year. You can buy such lamps online and in many drugstores, though it makes sense to talk with your doctor first, Lipman says, to rule out other possible causes of depression.

For those not helped by a light box, research suggests that cognitive be­havior therapy also eases SAD symptoms and might prevent them from recurring the next year.  

If none of those approaches help, talk to your doctor about medication. The antidepressant bupropion (Wellbutrin and generic) is approved by the Food and Drug Administration to treat seasonal affective disorder and to prevent winter depression. To learn more about bupropion and other antidepressants, see our Best Buy Drugs report on those medications.