Sunday, December 10, 2006

Your Health: Bright Light Can Banish Winter Blues

This is a good reason to get outside and go for walks on a daily basis if possible in the sunshine. A walk at lunch time can help with the winter blahs and humbugs as well as mild depression.

To your health and fitness,


Your Health: Bright Light Can Banish Winter Blues
By Rallie McAllister, M.D., M.P.H.

'Tis the season to be jolly, but for some folks, the month of December isn't the most wonderful time of the year. With the hectic pace of the holiday season and the arrival of colder weather, it's not uncommon to experience a mild case of winter blues.

Everyone's entitled to feel a little stressed out or down in the dumps in the winter months, but a major mood change is cause for concern. It could be a symptom of a debilitating type of depression called Seasonal Affective Disorder, or SAD for short.

While the exact mechanism of SAD isn't fully understood, it's thought to be related to the shorter days and weaker sunshine of winter. In susceptible individuals, shorter, darker days can cause biochemical imbalances in the brain that lead to depression.

Women in their twenties and thirties are most likely to develop seasonal affective disorder. Symptoms often begin in late November or December, and may not let up until April or May.

People who live along northern latitudes, or in areas that are perpetually cloudy and overcast, are most commonly affected. Residents of New Hampshire, for instance, are significantly more likely to develop SAD than their fellow Americans living in Florida.

Poor lighting conditions at home and at work also can contribute to seasonal affective disorder. If you live in a dark basement dwelling, or if you work in a gloomy, windowless building, you're at greater risk of developing SAD.

Signs and symptoms of the disorder range in severity, but they typically include feelings of sadness and social withdrawal. SAD sufferers frequently lose interest in their normal activities, and often avoid interacting with their friends and families.

Fatigue and excessive sleepiness are two of the most common symptoms. Some SAD sufferers are tempted to crawl into bed and stay there for the remainder of winter.

While seasonal affective disorder robs its victims of energy and enthusiasm, it usually has the opposite effect on appetite. People with SAD often experience an overwhelming desire to eat, and they often crave starches and sweets.

Eating candy, cookies, and other comfort foods may be a natural response to depression, since carbohydrate-rich foods can boost levels of a mood-enhancing brain chemical called serotonin. Many antidepressant drugs, including those used to treat seasonal affective disorder, work by increasing serotonin levels in the brain.

In addition to prescription medications, exposure to bright light can help alleviate symptoms of SAD. Light intensity, measured in units of lux, is typically greatest outdoors in the sunshine.

In fair weather, sunlight may be in the range of 5,000 to 20,000 lux, but it can reach a dazzling 100,000 lux on a sunny beach or snow-covered ski slope. Indoor light is far dimmer, ranging from 100 to 300 lux.

Sitting in a sunbeam or taking a walk outdoors during the sunniest part of the day can help dissipate mild symptoms of the winter doldrums, but more light is necessary for the treatment of SAD.

Physicians often recommend phototherapy, or bright light therapy, for their patients with seasonal affective disorder. When used as directed, phototherapy significantly reduces physical and emotional symptoms in approximately 80 percent of treated patients.

Phototherapy is easy: The patient simply sits in front of a specially designed lamp that emits bright light, ranging from 2,500 to 10,000 lux. Many SAD sufferers begin to feel better after their first treatment.

For patients who are sensitive to phototherapy, symptoms often resolve with a regimen that includes a single, 20-minute session each day. Patients whose symptoms are more resistant to treatment may require two 45-minute sessions daily.

The results of a recent study, conducted by researchers at Oregon Health and Science University, suggest that in addition to bright light therapy, low doses of the dietary supplement melatonin may help alleviate SAD symptoms. While the preliminary findings are promising, more research is needed to determine the optimal dose and timing of the supplement.

Whether treatment includes prescription antidepressant medications, phototherapy, or both, exercise is an important part of the program. As a proven mood-booster, physical activity can reduce the severity of depressive symptoms.

Folks with severe or debilitating symptoms of SAD should work with their doctors to design an effective treatment plan. If you've just got a mild case of the winter blues, on the other hand, a brisk walk in the sunshine might be all it takes to get you back in the holiday spirit.


Rallie McAllister, M.D., M.P.H., is a family physician in Kingsport, Tenn., and author of "Healthy Lunchbox: The Working Mom's Guide to Keeping You and Your Kids Trim." Her Web site is To find out more about Rallie McAllister, M.D., and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate Web page at

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