Fast Facts About Seasonal Affective Disorder

Far worse than the average “winter blues,” the phenomenon of depressive symptoms cycling with the change of seasons has been studied since the mid-1990’s. As we move into the fall and winter seasons, which are the most common seasons associated with this condition, here are some fast facts that the research has uncovered:

  • About 5% of the US population experiences seasonal affective disorder (SAD) each year, with higher prevalence in northern latitudes.
  • Women are diagnosed with SAD about four times more often than men.
  • Diagnosis of SAD requires the criteria to be met for major depressive disorder, along with a pattern of symptoms coinciding with season changes for at least 2 years.
  • Some symptoms commonly associated with SAD but which are not common for other types of depression, include cravings for carbohydrates, increased eating, and weight gain.
  • Most people with SAD experience symptoms during the winter months, but some experience symptoms during the summer months instead.

Three major types of treatments have been found to be effective for SAD:

  1. Light therapy aims to provide the light that we miss during the shorter, darker days of winter by providing artificial light every morning.
  2. Psychotherapy, specifically CBT tailored for SAD, aims to shift people’s thinking and behavior to combat the symptoms.
  3. Antidepressant medications have been shown to reduce symptoms of SAD, and since many people diagnosed with SAD are also found to have low levels of Vitamin D, taking a Vitamin D supplement may also be helpful, although the research on this has produced mixed results.

Because of it’s recurrent, predictable pattern, there is support for prevention: many people with SAD begin taking prophylactic measures in the weeks before their symptoms typically begin to set in, using light therapy or beginning antidepressant medications, or brushing up on CBT skills.

If you think you might suffer from seasonal affective disorder, talk to your doctor about your symptoms and the patterns you have noticed, and what treatment might be most appropriate for you. Be proactive and get ahead of this condition before the days get any shorter and darker!

Stuart L. Kurlansik, Annamarie D. Ibay. “Seasonal Affective Disorder.” Am Fam Physician. 2012;86(11):1037-1041.

National Institute of Mental Health (2016). Seasonal Affective Disorder. Retrieved September 25, 2018, from