Since the original publication of this post, some scientific consensus has developed regarding the link between Vitamin D deficiency, brain chemistry and mood disorders. A combination of adequate Vitamin D intake and blue light box therapy may be the most effective means of combatting SAD in addition to other general health maintenance measures.
It's no surprise that many people who live in Northern climes suffer from sunlight deprivation in the Winter. If you happen to work day shifts you may only catch glimpses of the sun rising and setting, or never see the sun at all depending on your latitude. Seasonal Affective Disorder (SAD) is essentially unheard of in those who live near the equator indicating its strong link to lack of daylight exposure. Unfortunately normal indoor lighting is simply not intense enough to have the desired positive physiological effects that sunlight does.
Depression has stalked me off and on for years - negatively impacting relationships, productivity and peace of mind, but I know it has taken a much greater toll in others. I have a close friend with a severe affective disorder dominated by depression who is unable to work, relies on a subsidized income, and has become alienated from family and friends. At his worst he has suffered hospitalization, and bouts of electroconvulsive (shock) therapy to regain some grip on reality and his moods. Obviously, severe depression or SAD can have terrible consequences including suicide, and so we should take every measure to adequately treat milder forms and prevent their progression.
It took many years to realize that my worst bouts of depression were usually in the winter, and more specifically the month of November. Of course SAD explains this pattern nicely. The onset of this SAD is so rapid that within a few days I can go from highly functional to a fairly depressed state as though the shrinking daylight in the fall suddenly triggers a switch in my brain. Fortunately my sister convinced me to start taking antidepressants during one severe November episode a few years ago, and after a few weeks I felt better than I had in years. After being on the drugs for a year or so I decided to stop them because of the side effects, and decided to try other measures to combat depression. Having said that I wouldn't hesitate to use antidepressants again if an episode of depression became too severe, or didn't respond to other measures. My depressive episodes have also been linked to a mild obsessive compulsive disorder, and that also improved with the medication, but again I sought other methods to deal with that. Through better understanding of these conditions, I can now effectively fight off the blues and OCD by getting proper rest, using cognitive behavior therapy, staying active, seeking good nutrition, and more recently by employing blue light therapy to combat SAD. If I am disciplined enough to use my light box regularly at the first signs of SAD I will experience a definite improvement in mood.
Of course like most treatments there can be side effects to light therapy as well(Saeed and Bruce):
Photophobia (eye sensitivity to light)
Hypomania (a mental state characterized by excessive excitability, optimism, hyperactivity, talkativeness, heightened sexual interest, quick anger and irritability and a decreased need for sleep)
Insomnia (if light therapy is used too late in the day)
Possible retinal damage (though this side effect has not been proven)
Despite these considerations I prefer to use light therapy rather than travel the road back down to taking antidepressants again. If you have free time during the day, then going for a walk of reasonable duration is a good alternative to using a light box. If you experience significant "winter blues" that might be related to SAD you should seek a medical opinion. If you are diagnosed with SAD, then your purchase of a light box to treat it might be one of the best investments you ever make. Not all light boxes are created equal though, and you should consider blue spectrum 470 nanometer LED lights as they are probably more effective while using much less light intensity than full spectrum boxes (easier on the eyes with less side effects).
Seasonal Affective Disorder, Depression, Light Therapy, Antidepressants, Obsessive Compulsive Disorder