Stay Cheerful

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If you’re feeling lethargic, craving carbohydrates and have an overwhelming urge to hibernate, you might be experiencing seasonal affective disorder (also known as SAD), a type of depression that strikes during the fall and winter months. More than 10 million Americans suffer from SAD each year, accounting for about one out of every three cases of depression in the United States. SAD is more common in northern latitudes, and women are four times more likely to develop SAD than men.

SAD is distinguished from other types of depression in that it has a distinct physiological basis. People who suffer from SAD are espec-ially sensitive to the reduced amount of sunlight that occurs during the shorter days of fall and winter. Because the disorder is often misdiagnosed or not diagnosed at all, many people don’t realize they are suffering from SAD. The effects of the disorder, however, can severely disrupt careers, education, relationships, home life and activities.

Do You Have SAD?

The key characteristic of SAD is that the symptoms occur seasonally, generally appearing in the fall and continuing until spring. A clinical diagnosis of SAD requires that the symptoms be experienced for at least two consecutive winters, followed by periods of normal moods in the spring and summer. There also must be no other explanation for the mood changes.

A range of symptoms make up SAD, including depression, anxiety, loss of energy, irrita- bility, changes in sleep patterns (especially sleeping more), changes in appetite (generally a desire for foods high in carbohydrates), weight gain, loss of sexual desire, decreased concentration and creativity, inability to complete tasks and social isolation.

Researchers believe that SAD is a natural physiological response to seasonal light changes and that some people are more negatively affected by these changes than others. The apparent reason for SAD is that when sunlight decreases, the body’s master biological clock has to adjust. The hormone melatonin (produced by the pineal gland), which regulates the sleep/wake cycle (circadian rhythm), increases with darkness and triggers the desire to sleep. Many animals slow down their activities or go into hibernation during the winter months, but obviously, hibernation isn’t an option for humans.

Research also shows that without sunlight, the brain doesn’t produce enough serotonin, which results in symptoms of depression.

Short of moving to a sunnier climate, there are a variety of things you can do to alleviate SAD. For the most part, the following suggestions will help anyone weather the cold and gray of winter with a brighter mood and more energy.

Brighten Your Mood with Light

To counteract the desire to hibernate, one of the most effective treatments for SAD is phytotherapy, or bright light therapy. Bright light suppresses the secretion of melatonin, which decreases the desire for excessive sleep and helps alleviate depression. If you suffer from minor symptoms of SAD, simply making the effort to spend at least 30 minutes outdoors in the sunlight every day can relieve symptoms. For more severe cases of SAD (or if you live in a particularly dreary climate), you’ll probably need to use a light box that produces an intensity of 2,500 to 10,000 lux (the measurement of light level). A light box employs lights that are up to 20 times brighter than normal indoor lighting. Bright light therapy requires sitting one to two feet from the light box for 15 minutes to several hours, depending on the severity of symptoms. Light box therapy is generally safe but can occasionally cause headaches, irritability or eyestrain.