Many people chalk up feeling blue in winter as simply a fact of cold weather and lack of sunshine. But 4 to 6 percent of people may have a winter depression which is clinically referred to as Seasonal Affective Disorder.
Another 10 to 20 percent may have mild SAD. SAD is four times more common in women than in men. Although some children and teenagers get SAD, it usually doesn’t start in people younger than age 20. Your chance of getting SAD goes down as you get older. SAD is also more common the farther north you go. For example, it’s seven times more common in Washington State than in Florida.