Understanding Seasonal Affective Disorder

When the temperature drops and the amount of sunlight we see each day gets shorter and shorter, it’s understandable that most people experience the winter blues. For some people, however, the winter blues is actually something much more serious: Seasonal Affective Disorder, or SAD.

SAD is a specific type of depression that typically strikes in late fall or winter in relation to the lack of sunlight during that time of year.  An estimated ten million Americans are affected by SAD, and another 1-2 million suffer from a mild form of it, meaning that it affects a total of one in every thirty people in the United States. Since SAD is related to sunlight, it’s more common the farther north you live; prevalence reaches 9.7% in New Hampshire, but it’s only 1.4% in Florida.

No specific diagnostic test exists for SAD; instead, it’s diagnosed through a patient’s history of seasonal depressive episodes. The disorder has been observed to run in families, so a genetic component seems likely; along the same lines, 55% of SAD sufferers reported a close relative with a severe depressive disorder, while 34% reported a close relative with an alcohol addiction. In addition to a lack of light exposure, SAD may be associated with low vitamin D levels in the blood.

There are several common myths surrounding SAD. For example, SAD is more than just a lack of energy or other negative feelings felt during the winter; milder conditions like that are commonly treatable by increasing physical activity. Also, the definition of SAD means that you only experience depression seasonally, during the last two consecutive winters; therefore, people who believe they have SAD do not suffer from other depressive conditions like clinical depression or bipolar disorder.

Some common symptoms of SAD include:

  • Tiredness
  • Fatigue
  • Irritability
  • Trouble concentrating
  • Poor sleep quality
  • Decreased activity level
  • Depression
  • Crying spells
  • Body aches
  • Loss of sex drive
  • Overeating and associated weight gains



If you’re suffering from these symptoms and think you may have SAD, you don’t just have to wait for winter to be over. Instead, try one of the treatments for SAD. For example, phototherapy is the exposure to natural or artificial (typically fluorescent) light for a certain amount of time every day, and 80% of SAD sufferers benefit from phototherapy and show quick improvements after beginning treatment. You may also be able to temporarily or permanently relocate to a more sunlit climate, and traditional therapy may help as well.