Seasonal Affective Disorder
What is it?
Seasonal Affective Disorder (S.A.D.) is characterized by recurring
periods of depression usually found during winter, although a few
cases have been noted in summer. It is found in about 4 to 10 percent
of the general population. It is a bigger problem for women than for
men. Women are about six times more likely to develop the disorder.
Even though women experience depression more than men, this is far
out of proportion with that difference (female to male overall depression
rate is 2:1). Up to 38 percent of people receiving treatments for
recurrent depression report seasonal changes. Some symptoms of
the illness include overeating with or without carbohydrate craving,
weight gain, and oversleeping.
Causes and Treatments
It is believed that these winter depressions are due to the lack of light
from the shortened days of winter. An effective treatment is
phototherapy. Phototherapy involves the use of bright light. Standard
treatment involves exposure to the bright light source for 2 hours in the
morning. Morning treatments seem to work better than evening
treatments, although it is not understood why. However, the
effectiveness of the treatment increases with increased light intensity
and duration of exposure.
There are many commercial lightboxes on the market to help people
with S.A.D. When purchasing a light box the key feature is that it
should be at least 2500 lux. Lux is a measure of the intensity and
energy of a light. Most products on the market are 10,000 lux. Of
course, this is something one can get without a prescription or doctor's