Seasonal Affective Disorder

With late summer nights long gone and the sun setting earlier every evening, it is common for seasonal depression to start to creep in on some of us this time of year. Less sunshine and more overcast days coupled with damp weather and more time spent inside can be a bit of a downer after a few months of basking in the afternoon rays. Similar to traditional depression, those suffering with seasonal depression can have an increased appetite (often for starches or sugars, leading to weight gain), more hours spent in bed (or difficulty getting out of), irritability, feelings of inadequacy & a general inability to perform daily tasks. Women are four times as likely as men to suffer from SAD, and those between the ages of 20-40 are most affected, up to 25% of the population.

In Canada in particular since we are so much further north than the US (where many more studies are generally done) sometimes the common ‘winter blues’ can be chalked up to a vitamin D deficiency. In colder weather, we tend not to spend much time outside, and even if we do the time frame during which the UV rays from the sun can make it down to the earth is limited (and lets be honest, there are many more overcast days than clear skies anyways). Therefore, supplementing vitamin D in the winter months is a wise idea for all Canadians. The recommended dietary allowance (RDA) as per Health Canada is 600IU (international units) for those aged 9-70 years, though the tolerable upper intake level (/UL) is 4000IU for the same age group. Vitamin D is a fat soluble vitamin (like vitamins A & E) so excess of this vitamin is stored in the body for later use, whereas extra water soluble vitamins (like the B’s & C) will simply be eliminated from the body. It is important not to exceed the upper limit.

Aside from pharmacological antidepressants, a common treatment for Seasonal Affective Disorder is the use of a full spectrum light box (interestingly in one study, researchers found that patients responded best to “sky blue” within the light spectrum). The light was ineffective unless taken in through the eyes, so a patient could spend a few hours in front of a box reading, but not sleeping. A healthy balanced diet & exercise regime are also crucial parts of any depression treatment plan.