Here we are, once again.  Winter time. 

Snowy beauty this morning in the mountains as I shoveled the driveway and a path around to the back of the house.  Bernard isn’t able to have these glorious outdoor moments right now, stuck in bed as he is, and I worry about that. 

We all get a lot less sunlight at this time of year, in this part of the world.  The rates of Seasonal Affective Disorder (SAD) run between 2-3% of the population here in Canada, with a milder form of the problem, Subsyndromal Seasonal Affective Disorder up even higher, around 15%.  Even on this bright snow day, clouds cover the sun and prevent it from entering my eyes directly.  Luckily, the snow reflects the available light and I received a good dose of the light stuff.  Bernard is pretty much stuck inside for most of this season, and this could dampen his mood and energy as well as his circadian rhythm.  Researchers think that lack of sunlight can affect our internal clocks, changing the timing of hormones and causing the symptoms of Seasonal Affective Disorder. 

The Canadian Mental Health Association sites the symptoms common to SAD:

change in appetite
cravings for sweet or starchy foods
weight gain
decreased energy
fatigue
oversleeping
difficulty concentrating
irritability
avoidance of social situations
feelings of anxiety and despair

Obviously you should follow the advice of your doctor in treating symptoms  that seem like SAD.  One of the main treatments for these seasonal symptoms, and to correct mussed up circadian rhythms is light therapy.  Last month, in preparation for the winter ahead, I researched and purchased a full spectrum light.

There are a number of companies and types of lamps to choose from (if you’re ordering online).  I went with the ‘Day Light’ from Uplift Technologies, mostly because it was available in town and was on sale.  It’s about 18″ tall by 12″ wide, with three high quality non-flickering flourescent bulbs which emit 10 000 lux at 12″ away, with negligable ultraviolet radiation. 

10 000 lux is generally used for light therapy.  If you use a weaker light, or you are located farther away, then the light is much less effective.  This is because light intensity is inversely proportional to the square of the distance (meaning: if you double the distance, you only get one quarter the light, or lux, and if you triple the distance you only get one ninth!). 

Some examples of illuminance 

• Full moon overhead at tropical latitudes = 1 lux
• Office lighting = 320-500 lux
• Overcast day = 1000 lux
• Direct sunlight = 32,000-120,000 lux!

Our experience with the light has been positive.  Bernard feels it can initially stress him out with its intensity, but that mostly it makes everything brighter and more cheerful.  I’ve been using it mornings while I have coffee and sit at the computer.  And, once I get over the initial shock of brightness, it’s wonderfully refreshing.  I’m a little bit light drunk by the time I’m done.