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What is Seasonal Affective Disorder?

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Seasonal Affective Disorder (SAD) (also called winter blues, winter depression, etc.) is a type of depression that follows the seasons. SAD sufferers begin to develop symptoms of depression in September or October. The most difficult months for SAD sufferers are January and February, and symptoms begin to subside in April or May, with a full remission of symptoms in the late spring and summer.

Symptoms Include:

  • A change in appetite, especially a craving for sweet or starchy foods
  • Weight gain
  • A heavy feeling in the arms or legs
  • A drop in energy level
  • Fatigue
  • A tendency to oversleep
  • Difficulty concentrating
  • Irritability
  • Increased sensitivity to social rejection
  • Avoidance of social situations

How common is SAD?
An estimated 35 million North Americans have SAD or winter depression. It usually doesn't start in people younger than 20. SAD is more common in northern geographic regions.

Possible Cause of this Disorder
Longer periods of darkness causes an increase in melatonin secretion by the pineal gland, which may increase symptoms of depression.

SAD can be caused by a variety of factors such as:

  • Change of seasons – lessening of day light in fall and winter
  • Change in time/time zones
  • Light deprivation
  • Shift work


  • Get the Sun in your face! Spend time outdoors during the day. Studies have found that an hour’s walk in winter sunlight is as effective as two and a half hours under bright artificial light.
  • Get the Sun in your house! Arrange your home and study area to receive as much sunlight as possible.
  • Phototherapy or bright light therapy has been shown to suppress the brain’s secretion of melatonin. Light boxes are available to replace the natural light of the sun. (See links below.)
  • An antidepressant drug may prove effective in reducing or eliminating SAD symptoms if phototherapy doesn’t work.

Discuss your symptoms thoroughly with your family doctor and/or mental health professional.

For More Information:

ATSU Mental Health Wellness Counseling

MO Campus - 660-626-2424

Thom Van Vleck

Sarah Thomas


AZ Campus - 480-219-6170

Art Davalos-Matthews

Society for Light Treatment and Biological Rhythm

P.O. Box 591687
174 Cook Street
San Francisco, CA 94159-1687

Light Therapy Solutions

(800) 699-1066

SunBox Company

19217 Orbit Dr.
Gaithersburg, MD 20879
Phone: 800-548-3968

National Mental Health Association

2001 N. Beauregard Street, 12th Floor
Alexandria, VA 22311
Phone 703/684-7722
Fax 703/684-5968
Mental Health Resource Center
TTY Line 800/433-5959