Friday Factoid: The Season of Seasonal Affective Disorder

Rebecca Girlinghouse, MA

WKPIC Doctoral Intern


It’s that time of year again where the sun starts to set sooner and sooner, especially once we hit the end of Daylight Savings Time on November 3rd.  It is around this time of year that many begin to experience the effects of something called Seasonal Affective Disorder (SAD).  Over 10 million Americans each year struggle with this disorder, and another 10 to 20 percent experience mild symptoms associated with SAD (National Institute of Mental Health [NIMH], 2016).  This leaves many of us questioning why exactly the change in the season can have such drastic effects on our mood and what can be done about it.


There may be several reasons why the change in season—especially the change between Summer, Fall, and Winter—can have an effect on our mood.  Studies have found that the decrease in sunlight can affect several chemicals in our brains that affect our mood.  For example, when we have less exposure to sunlight, the levels of melatonin in our bodies change, and so we start to feel sleepier and have less energy. Also, our bodies produce less vitamin D when our exposure to sunlight decreases (NIMH, 2016).  Vitamin D is essential in helping us absorb other nutrients that keep us healthy and happy (Office of Dietary Supplements, 2019).  Additionally, those with symptoms of SAD tend to have higher levels of serotonin (a chemical in the brain associated with mood) during the winter compared to those without such symptoms (NIMH, 2016).


There may be several ways to combat the effects we feel during this time of year.  First, it may be helpful to seek counseling or take Vitamin D supplements.  Another interesting solution to this problem is something called light therapy (Golden, Gaynes, & Ekstrom, 2005).  This involves exposure to light that mimics the sun anywhere from 20 to 60 minutes a day (NIMH, 2016).  Sometimes, people use something called a light box to get the exposure to light they need to feel better.  The best part about using a light box for light therapy is that it can be done at home or even at work.  The light boxes come in all shapes and sizes, and some models are very affordable.  It’s a nice option for those who are not to the point where they need medication, those who are on the go, or those who don’t have a lot of money to spend on expensive treatments.



Golden, R.N., Gaynes, B.N., & Ekstrom, R.D. (2005). The efficacy of light therapy in the treatment of mood disorders: A review and meta-analysis of the evidence. American Journal of Psychiatry, 162, 656-662.


National Institute of Mental Health. (2016). Seasonal Affective Disorder.  Retrieved from


Office of Dietary Supplements. (2019). Vitamin D fact sheet for consumers. Retrieved from

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