Seasonal Affective Disorder (S.
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), also sometimes called Winter Depression affects about 1-3% of people in the temperate climate zone (i.
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, Canada's climate zone).
Although it most commonly occurs in women in their childbearing years, it affects all populations, children included.
Although some claim it is the product of a hypochondriacs imagination, it is recognized in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders.
4th edition.
as a genuine psychiatric condition.
The symptoms of S.
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include lethargy and increased need for sleep, anxiety, depression, lack of interest in previously enjoyed activities, and carbohydrate craving.
The cause of S.
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is unknown, but several theories exist.
Biochemical theories tend to focus on the brain chemicals serotonin and dopamine and the amino acid tryptophan, and suggest that S.
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sufferers have abnormally low levels of these substances.
Another common biochemical theory involves deregulation of melatonin secretion.
Melatonin is the chemical the body secretes in response to darkness.
Melatonin regulates the body's circadian "clock".
Decreased sunlight in the fall and winter months and/or decreased sensitivity of people with S.
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to light have been suggested as possible causes for disrupted melatonin secretion.
Lastly, there exist evolutionary theories for the existence of S.
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that hold the symptoms associated with S.
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may have conferred an evolutionary advantage on our ancestors.
Females, who apparently tended to become pregnant in the summer, by sleeping and eating more and gaining weight in the winter increased their offspring's chances of survival by "nurturing" themselves in this way during pregnancy.
There is general consensus that the most effective means of treating S.
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is light therapy, which is effective in more than 60% of S.
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cases.
Light therapy typically takes the form of sitting in front of a "lightbox", which emits broad spectrum (similar to natural light but without UV radiation) light.
In studies, effective treatment periods range from 30 minutes to 2 hours, with sessions occurring two or more times a week.
There is some evidence that treatments are more effective when performed in the morning.
A regimen of regular exercise can increase the effectiveness of the light therapy.
Although it is generally agreed that a balanced diet is an important in the management of S.
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, there is very little research into nutritional supplements specifically for use in S.
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One study has found that vitamin D supplementation resulted in increased positive mood in S.
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patients.
In conventional medicine, anti-depressant medications are often used as adjuncts in S.
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treatment.
Following this same reasoning, 5-hydroxytryptophan (5-HTP), a dietary supplement that has been used in the treatment of depression and anxiety may be considered as a means of addressing these symptoms in S.
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5-HTP is a product of tryptophan metabolism in the body, and is further metabolized to serotonin, which addresses some of the observed biochemical deficiencies commonly found in the S.
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population.
5-HTP should not be used by people who are pregnant or using conventional medications without first consulting a professional health-care provider.
Possible side effects of 5-HTP use include nausea, vomiting, diarrhea, and anorexia.
St.
John's Wort has been shown to be effective in the treatment of mild-moderate depression, and may be considered in the management of S.
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as well.
It is hypothesized that St.
John's Wort works by much the same mechanism as conventional anti-depressants known as selective serotonin reuptake inhibitors, by allowing serotonin to remain active in the body for longer periods.
St.
John's Wort should not be used by pregnant or lactating women, or by people using conventional medications without consulting a health professional.
Although considered safe if used appropriately, side effects of St.
John's Wort include gastrointestinal discomfort, headaches and photosensitivity (i.
e.
, extreme sensitivity of the skin to light).
Finally, certain lifestyle interventions are important in the management of S.
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Keeping living and work environments well-lit, sitting near a window at work and spending at least some time out of doors, especially on sunny days can help to minimize S.
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's hold on your life.