Seasonal Affective Disorder: Winter Is Coming

The seasons are changing, which can trigger our moods.

Posted Nov 03, 2020

The temperatures are dropping, the leaves are changing, and the days are becoming shorter—all of these changes from summer to fall means that winter is just around the corner. Many individuals look forward to winter because of the holidays and the beauty of the snowfall. For others, the change from summer to fall can be trigger depression. The "winter blues" can be just around the corner. 

What is SAD?

Seasonal affective disorder (SAD) or seasonal depression is a type of depression that comes with the seasons. Seasonal affective disorder is most common during the winter months, but oddly enough, it also appears in the summer, although it's not nearly as prevalent. According to research, "A small share of people with SAD show the reverse pattern, being sensitive to summer's longer days. The very existence of opposite winter-summer patterns suggested to researchers that this mood disorder stems from a problem in adapting to the physical environment." 

Individuals with seasonal affective disorder must meet major depressive disorder criteria with symptoms coinciding with the specific seasons and lasting for at least two years. 

Who is at risk of developing SAD? 

Researchers believed that SAD's typical appearance in the winter had a high correlation with the lower exposure to light. The obvious next step was to lengthen exposure to light intensity to mimic the outdoors. By 1998, researchers were studying light treatment variations as a treatment for SAD. 

Individuals who live further from the equator are more at risk for developing seasonal affective disorder than individuals who live closer to the equator. One percent of individuals who live in Florida have SAD, whereas nine percent of individuals who live in Alaska have SAD. Females are more at risk of developing SAD compared to males, and individuals who have a history of depression or bipolar disorder are also at an increased risk of developing SAD. Individuals who have an increased level of melatonin and decreased serotonin and vitamin D levels are also at a higher risk for developing SAD. 

"Sunlight plays a critical role in the decreased serotonin activity, increased melatonin production, disrupted circadian rhythms, and low levels of Vitamin D associated with symptoms of SAD," according to a study published in Depression Resistant Treatment

Light therapy to treat seasonal depression

Not any type of bright light is known to treat individuals with SAD. There are certain light therapy boxes that filter out UV light that are used to treat SAD. Lightboxes that have UV rays are used to treat certain skin disorders. Below are key points to keep in mind when using phototherapy to treat your seasonal affective depression. 

  • Use a lightbox that is 10,000 lux, which is 20 times the strength of typical indoor lighting. 
  • You can order a lightbox online. 
  • Use a lightbox that blocks out 99% of UV rays. 
  • Position the lightbox above your head to mimic natural outdoor lighting. 
  • Use the lightbox in the morning for 20 to 60 minutes.
  • Use the lightbox daily from early fall through winter. 
  • Ask your doctor about using your lightbox if you are on certain medications that cause photosensitivity. 
  • Monitor your mood weekly by journaling about your emotions to assess whether light therapy is working. 
  • Phototherapy should also be combined with other therapeutic approaches such as cognitive behavioral therapy and anti-depressants if you do not see an improvement in your mood.