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What is Seasonal Affective Disorder?

Question: What is Seasonal Affective Disorder?
Answer: Seasonal Affective Disorder (SAD) is a pattern of significant depressive symptoms that occur and then disappear with the changing of the seasons. SAD is sometimes called "Winter Depression" or "Winter Blues". SAD occurs when days get shorter around November and reduce with the onset of Spring. Incidentally, SAD can have a "reverse seasonal pattern" where depression occurs in summer months.

Question: What's the difference between Seasonal Affective Disorder and other forms of depression?
Answer: SAD is a subcategory of Major Depressive Disorder. Symptoms, though, occur seasonally, so symptoms come in cycles..

Question: How many people are affected by SAD each year?
Answer: SAD affects millions worldwide. The illness is more common in higher latitudes (locations that are farther north or south of the equator) because of their distance from the sun. Research also shows that women are more prone to SAD than are men.

Question: What are the symtpoms of SAD?
Answer: Symptoms include many of the same symptoms of depression: sadness, anxiety, lost interest in usual activities, withdrawal from social activities and an inability to concentrate. The difference though, is that these symptoms resolve each Spring and tend to occur again in late Fall.

Question: What is the cause of Seasonal Affective Disorder?
Answer: Melatonin, a sleep-related hormone secreted by the pineal gland in the brain, has been linked to SAD. This hormone, which may cause symptoms of depression, is produced at increased levels in the dark. Therefore, when the days are shorter and darker the production of this hormone increases.

Question: What kind of treatments are available?
Answer: Phototherapy or bright light therapy has been shown to suppress the brain’s secretion of Melatonin. Antidepressants are helpful as well. For mild SAD symptoms, spending time outdoors during the day or sitting in a pool of sunshine indoors are helpful. Studies have shown that an hour’s walk in sunlight was as effective as two and a half hours under bright artificial light. Daily exercise has been shown to be helpful, particularly when done outdoors. Keeping a healthy sleeping and eating pattern is also recommended.

Question: How to Seek Treatment for SAD?
Answer: If you've noticed a pattern to your depression, make an appointment with your physician. Medical tests and exams should be up to date to rule out any other reason for depressive symptoms. Thereafter, a consult with a psychologist, social worker or psychiatrist is necessary. A treatment plan of light therapy, medication, talk therapy or a combination of them may be recommended.


Seasonal Affective Disorder Association:

Society for Light Treatment

The Circadian Lighting Association:


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