SEASONAL AFFECTIVE DISORDER

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. 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 friends and family. 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 can have the opposite effect on appetite. People with SAD often experience an overwhelming desire to eat, and they often crave starches and sweets. Eating cakes, biscuits, and other comfort foods may be a natural response to depression, since carbohydrate-rich foods can boost levelsof a mood-enhancing brain chemical called serotonin. Manyantidepressant drugs, including those used to treat seasonal affective disorder, work by increasing serotonin levels in the brain.

In addition to prescription medicines, 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.

Doctors often recommend phototherapy, or bright light therapy, for 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 a straightforward treatment .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 can be resolved with a course that includes a single, 20-minute session each day. Patients whose symptoms are more resistant to treatment may require two 45-minute sessions daily.

Recent studies have suggested 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. People with severe or debilitating symptoms of SAD should work with their doctor 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 on course.