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Seasonal Affective Disorder (SAD): Beating the 'Winter Blues'

Many of us are familiar with the appropriately abbreviated “SAD,” or Seasonal Affective Disorder, a type of depression that is triggered by the seasons of the year. This winter-onset depression affects an estimated 4-6% of Americans each year, and as many as 10-20% of Americans report experiencing milder versions of SAD. Not so surprisingly, it has been found that over 80% of people with SAD report having at least one relative who has suffered from a major depressive disorder or alcohol abuse. (NAMI)

We now know that SAD symptoms likely result from the naturally changing availability of sunlight during the late fall and winter months. Despite this most probable cause of the disorder, many people often attribute their symptoms to the changes in climate, lack of exercise, increased isolation and/or their annual “Holiday weight-gain.” However, these familiar symptoms might actually be a result of SAD, and when added to lowered affect due to lack of natural light, a spiteful, yet easily treated cycle tends to occur.

What are the symptoms of SAD?

While not everyone diagnosed with SAD experiences the same symptoms, winter-onset SAD typically begins in late October, lasts throughout March or April, and is characterized by decreased mood, daytime fatigue, oversleeping, increased cravings for sweets and carbohydrate-rich foods, weight gain, irritability, difficulty concentrating, social withdrawal and increased emotional sensitivity. Summer-onset SAD, which is less commonly reported, is usually characterized by insomnia, irritability or anxiety, decreased appetite and weight loss.

What are the causes of SAD?

It is thought that the photoreceptors in the lower half of the retina are sensitive to changes in light, and that visible light triggers the release of a natural anti-depressant effect in the brain. While the causes of SAD remain uncertain, experts believe that the availability of light in one’s environment directly correlates with the number of people reporting symptoms. Sufferers report their winter depressions to be more severe and longer-lasting, the farther north they live. They also report worsening symptoms during overcast weather or decreased exposure to indoor light.

How can I treat my symptoms?

Light box therapy is the most common method of treatment for SAD, as studies suggest between 50% and 80% of patients treated with the proper amount of light therapy report essentially a complete remission of symptoms. Light boxes for personal use range in cost from $35 to $200+. A bright fluorescent light box that filters out UV rays and a color temperature between 3,000 and 6,500 degrees Kelvin has been shown to be most effective for treatment. The light should sit on a table top at eye-level, for between 20 and 60 minutes daily for best results. The light should be able to produce up to 10,000 lux. (a normal household light produces 150-300 lux.), and be able to adjust downward.

Sufferers of SAD who live in more southern, sunny climates such as Southern California, may be able to experience similar effects to light box therapy by increasing their daily time spent outdoors, or in well-lit indoor environments. Exposure to UV rays from the sun are not linked to improving SAD symptoms, although some experts suggest increasing Vitamin D levels from skin exposure to sunlight might play a role in improving mood and reducing symptoms of depression, anxiety and irritability.

What should I do if I think I have SAD?

If your symptoms are mild – that is, if they don't interfere too much with your daily living, you may want to try light therapy as described above or experiment with adjusting the light in your surroundings with bright lamps and scheduling more time outdoors in winter.

If your depressive symptoms are severe enough to significantly affect your daily living, consult a mental health professional qualified to treat SAD. He or she can help you find the most appropriate treatment for you. To help you decide whether a clinical consultation is necessary, you can use the feedback on the Personalized Inventory for Depression and SAD at (NAMI)


National Alliance on Mental Illness (NAMI) website:

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