Seasonal Affective Disorder: What You Need to Know

For some people, the shorter days of the fall and winter months bring with it an increase in depressive symptoms.  This type of depression has been called Seasonal Affective Disorder (SAD). It usually impacts people during the change of seasons when there is a decrease in light, and it lessens or stops when the seasons change again, bringing additional light. 

Studies showing the numbers of people with SAD vary from about half a million people (4-6% of the population) up to 10-20% of the population in the U.S.  

Symptoms of SAD include:

  • being sluggish/low energy/ fatigue; reduced sex drive
  • losing interest in activities that once were pleasurable
  • decrease in social interactions
  • experiencing difficulty concentrating
  • sleep problems
  • gaining or losing weight
  • feeling depressed most or all of the day, almost every day
  • feeling worthless or hopeless
  • having frequent thoughts of suicide
  • The symptoms occur for more than two weeks and recur during the same time of year

What Causes SAD?

The exact cause of SAD is still to be determined, however most theories attribute the disorder to the lessening of daylight hours.  This can disrupt circadian rhythms (the body’s internal clock), increases the production of melatonin (causing sleepiness, the body’s way of telling us when it is time to go to bed), and decreases the production of serotonin (which helps to regulate mood).

It’s more prevalent in the northern than southern States.   Not everyone gets treatment for SAD as it is typically attributed to the “winter blues” or “cabin fever” and there is an expectation to just ignore it, endure it or “man up”. 

Now, the good news. SAD can be treated. 

First, if you feel you may have SAD, after looking at the symptoms listed above, it is recommended that you see your doctor to determine whether it is due to a medical cause (i.e.: hypothyroidism or another medical condition) and a therapist to assess if symptoms are due to SAD or another diagnosis (Depression, Bipolar disorder or trauma).  During the therapist’s assessment you might be asked to fill out the Seasonal Pattern Assessment Questionnaire or a depression questionnaire.  These will help determine the cause of your symptoms. 

Next, depending on the symptoms and their severity your doctor may prescribe medication, light therapy and CBT therapy. 

  • Medication: Selective Serotonin Reuptake Inhibitors (SSRIs) for depressive symptoms.
  • Light box therapy: A prescribed therapy using light to reset circadian/ biological rhythms. Work with your doctor due to changes in length of time, intensity and type of light used.
  • Cognitive Behavioral Therapy – To change the pattern/thoughts/ behaviors leading to the symptoms.

If you are diagnosed with SAD there are a number of things that you can do.

  • Educate yourself and your family about SAD and any treatments.
  • Increase the amount of light you get each day by: going outside, allowing natural light to shine inside, rearranging work areas, going without sunglasses, sitting in the sunshine or next to a window in classrooms, restaurants, and other places.
  • While it is light out, avoid dark areas. This increases the level of melatonin.
  • Exercise outside or facing a window to maximize the amount of sunlight.
  • Be aware of the temperature and dress warmly due to sensitivity to cold.
  • Putting a timer on lights so that the lights go on one half hour or more before awakening. This has made it easier for some people to wake up in the morning.
  • Keep a daily record of energy levels, moods, appetite/weight, sleep times and activities to track biological rhythms.
  • Stay on a regular wake/sleep cycle to increase alertness and decrease fatigue.
  • Postpone making major decisions in your life until the season is over and symptoms abate.
  • Share experiences/treatment with others who have SAD.

For those who are still interested in learning more about SAD please read the following articles:


Author: Cynthia Booker-Bingler, LCSW, Health Affiliates Maine

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