When I moved to California, my life changed completely. I experienced tremendous personal growth and my career advanced more than satisfactorily. I came out of my shell. Old friends would look at me and comment "You've changed." without being able to tell me how I'd changed. Then I moved to Michigan and started backsliding. I began to exhibit behaviors that I thought I had outgrown. I'd get cranky and irritable for no discernible reason. I'd experience periods of listlessness where I could just barely get myself off the couch and couldn't work up any enthusiasm even for projects about which I was excited. I started going back into my shell. Now, before California, I thought that was how life was, and that I was just, well, imperfect. After California, however, I suspected that it wasn't me. I mean, I couldn't be ungrowing the growth I'd experienced in California.
After a while, I heard about this thing called "SAD." At first, I thought nothing of it, but, gradually, I started thinking that there might be something to it. Of course, deep down, I felt that I couldn't have it. I mean, I control my own behavior, don't I? I couldn't possibly be different because of a silly thing like changes in light. I grew up in the North! In winter, I went to school in darkness and came home in darkness! Sometimes the street lights would be on all day! Your activities change in winter, but you don't! Then I met my friend, Judy, who had been diagnosed with SAD and was being treated for it. She suggested that I read a book by one of the researchers who had done seminal work on SAD. I did. I cried. Literally. Here was what I had tried telling people all my life. Finally, someone understood.
So, I bought a light box. By January, the two hours a day I could manage to spend in front of it weren't enough. I tried anti-depressants. They made me feel dreadful. I wasn't depressed. But I wasn't happy. I felt as though I were in an emotional box with neither room to stand up or sit down. And, they cut into my stamina. I had been swimming an easy 2-3000 yards, now a 1000 was an effort. I tried St. John's wort. That worked well emotionally, but, again, cut into my stamina. (Not that I swim competitively, but I don't like messing up one thing to fix another. Who knows what else is getting messed up?)
Meanwhile, Judy and I had been attending a weekly dance class. Every week, we'd compare notes and found that our ups and downs were identical. "Wasn't Saturday just awful?" "Oh, Thursday, was great, I got so much done!" One day, in February, after we'd had a couple of days of actual sunshine, I went to class. Before I had even changed my shoes, Judy came bouncing over, chattering a mile a minute. After having seen the two of us moping about, struggling to find words all winter, the class could not shut us up! That made it clear to me: SAD is very very real and I have it.
I decided that there was no reason for me to live that way and got out of Michigan. It took about a year to recover from four years there. In December, I visited the mid-West, including Michigan. Nearly everyone I saw, and nearly every Christmas card I received from people I'd seen in the previous few months, commented on how well I looked and how happy I seemed. I will never again live in a sun-challenged area. Not only is it too taxing emotionally, it is also socially isolating: When the sun is gone, I'm moping at home. Everyone else goes off to work. When the sun comes out, I settle down to work. Everyone else goes off to play.
One of the reasons that it was so difficult for me to diagnose and believe that I have SAD is the asymmetry of my response to light. It takes days of deprivation for depression to set in, but only hours of exposure to prevent or begin to clear it. Now, of course, I am sensitized and can feel both when I need to go catch some rays and when I've had a sufficient dose. Unfortunately, you can't stock up for more than a day or two. I use St. John's wort when I travel.
Seasonal Affective Disorder (SAD) is a mood disorder in which seasonal variation in an environmental factor¾most commonly light intensity¾causes clinical depression. Most sufferers have winter SAD, which means that they become depressed as a consequence of insufficient exposure to light. (In contrast, summer SAD sufferers become depressed because of too much light.) Upon hearing about SAD, many people will respond "Oh, I have some of that." Probably about 90% of people have winter blues: they experience mood changes with varying light levels. However, estimates are that maybe up to 10% have SAD: they become clinically depressed. SAD typically sets in around puberty. In pre-menopausal age groups, women are four times more likely to have SAD than men. This difference disappears in older age groups.
The causes of SAD are unknown, but it seems to be related to serotonin levels and the production of melatonin. These are associated with the regulation of the body's daily clock, and many SAD sufferers are particularly sensitive to time changes such as jet-lag or daylight savings. One theory is that sufferers of winter SAD are less sensitive to light, so need higher levels to trigger melatonin production. SAD often runs in families and is suspected to have a genetic factor. (Although my sister doesn't have even a trace of winter blues: She spent five years on Greenland, 300 miles North of the Arctic circle, and functioned normally the entire time.) Ethnic populations from Northern regions exhibit a higher incidence, which seems counter-intuitive until you think about natural selection. (Whose genetic material is more likely to be propagated? That of someone home in bed all winter, or that of someone out wrestling polar bears?) The effects of SAD are cumulative, in both the short and the long term, that is, the depression worsens as periods of low light lengthen, and occurs faster with successive annual cycles. Fortunately, while SAD-induced depression may leave sufferers unable to function normally, it is rarely suicidal. (You just feel like a slug that doesn't quite have enough energy to hibernate.)
There is no means of clinical diagnosis. If you respond to the treatment, you've got it. The most effective treatment for winter SAD is high-intensity light, such as strong sunshine. A variety of light-boxes are available that emit high-intensity light with the harmful rays filtered out. (The key is light intensity, not spectrum.) These are typically designed to be placed in front of someone seated or worn (as in a visor). Symptoms of SAD can be treated with anti-depressant medication, but dosages have to be adjusted constantly to allow for varying levels of light. Note that, while all depressions are bio-chemical imbalances, SAD-induced depression has physiological roots. Unlike depressions with psychological roots, it can't be overcome by psychological means. Telling someone with a physiologically based depression to "Pull yourself together and snap out of it" is like telling someone with a broken leg to "Stop whining and walk." (I remember sometimes thinking "Why am I so depressed? I'm not in the mood to be depressed. I don't feel like being depressed.")
And, no, SAD is not contagious. It would probably be easier to live with if it were.