Shedding Light on Seasonal Depression

March 11, 2020

It is perfectly normal for bears to hibernate, but not people. But for some, the winter months bring on a kind of hibernating and social withdrawal. Dr. Jenys Allende, Executive Director for Mental Health Staffing with Legacy Treatment Services, said that while you might pass off "winter blues" as a fact of life in winter, it is something you should  plan to speak to your doctor about. 

Seasonal Affective Disorder
Seasonal Affective Disorder (SAD) is a very real thing, according to Dr. Allende. "SAD is a variant of Major Depressive Disorder (MDD), where for at least two weeks you have a depressed mood or loss of interest in things you normally enjoy.  Other symptoms of depression such as changes in sleep, appetite and lack of concentration that significantly impact your ability to function."

The National Institute of Mental Health (NIMH) classifies SAD as a type of depression that comes and goes with the seasons, typically starting in late fall and going away during the spring and summer. Depressive episodes linked to the summer can occur but are much less common than winter episodes of SAD, according to the NIMH. 

Symptoms of Major Depression

  • Feeling depressed most of the day, nearly every day
  • Feeling hopeless or worthless
  • Having a low energy level
  • Losing interest in activities you once enjoyed
  • Having problems with sleeping
  • Experiencing changes in your appetite or weight
  • Feeling sluggish or agitated
  • Having difficulty concentrating
  • Having frequent thoughts of suicide

Symptoms of Winter Seasonal Affective Disorder

  • Having low energy
  • Excessive sleeping
  • Overeating 
  • Weight gain
  • Craving carbohydrates
  • Social withdrawal-feel like hibernating 

Dr. Allende said SAD is a variant of Major Depressive Disorder (MDD), where you are experiencing a depressed mood and loss of interest for at least two weeks. Other symptoms of depression usually accompany it (changes in sleep appetite, concentration, etc.) and significantly impact your ability to function. She indicates that the "winter blues" is a milder form, where you may not have these symptoms all the time. You can function, even if it is a bit more difficult than during the summer.  The research shows that 75% of the patients affected by SAD are women. The psychiatrist cautioned that depression is not something to ignore and think it will pass on its own. MDD has a high risk of recurrence, according to Dr. Allende. There is a 50% chance of recurrence after one episode of MDD and about an 80% chance after a second episode.

Treatment for SAD
Dr. Allende differentiates between SAD and winter blues stating winter blues can be managed by lifestyle modifications such as getting outside, exercising, living a healthy lifestyle and connecting with friends and family. She said SAD generally requires treatment and light therapy has proved to be an effective treatment for SAD.  She added that the needed exposure to light is not a standard light bulb but rather what is recommended is a 10,000 Lux light, which is roughly 20 times stronger than a typical indoor light. The recommended exposure to light is with a light box positioned two feet away at 2 o'clock or 10 o'clock for 20 minutes twice a day or more if recommended. Antidepressants like Wellbutrin help prevent depression, but they do carry a slightly higher risk of nausea and insomnia.

Scandinavia's unique battle with winter blues
Dr. Allende shared a story of Rjukan, a small town in Norway, that sits between two mountains where it is difficult to see the sun. The town came up with a solution and built large mirrors that reflect the sun on the town square, and residents gather to enjoy it. Another example of a town resisting SAD is Tromso, Norway – a community 400 km above the Arctic Circle. Dr. Allende said the people in the community prepare for the long winter and darkness by developing a "winter mindset." To them, it is a cozy time to invite people in and enjoy this time together. They will sled or do other activities outside wearing headlamps. While some innately adapt a “winter mindset” other can use cognitive behavioral therapy (CBT) to adapt coping skills for SAD. CBT is effective in preventing and treating SAD.

In Sweden, they are currently doing studies using bright lights in classrooms with the windows shut. The lights mimic the outdoors and help students avoid lethargy that is associated with winter blues symptoms. The students report improvement in sleep cycle and the hope is their school work will also improve.

The science behind SAD
Dr. Allende said research on SAD indicates that the cells in the eyes are particularly sensitive to blue light and communicate with many areas that feed our circadian clocks, sleep centers and mood regulation center. In mice, bright light at inappropriate times of the day led to decreased interest in activities. The phase-shift hypothesis: with the shortened day, our circadian rhythm falls out of synch with the actual time of the day because of the delay in the release of melatonin. The melatonin levels are suppressed by light and increase at night in response to the darkness. 

Dr. Jenys Allende is the Executive Director for Mental Health Staffing with Legacy Treatment Services. For more information about the services Legacy offers visit or call 800-433-7365.