SIU School of Medicine

Jump directly to a section:

Office of Public Affairs


Seasonal Affective Disorder (SAD)


If this winter you are feeling blue, gaining weight and waking up tired even though you might be sleeping more, you may have seasonal affective disorder. 

Seasonal affective disorder, or SAD, is a type of depression that affects an estimated half million people every winter.  It is caused by a biochemical imbalance due to the shortening of daylight hours and the lack of sunlight in winter.  Ron Zec, Ph.D., associate professor of neurology and psychiatry, at SIU School of Medicine in Springfield, explains the symptoms.

“The typical ones would be the more or less typical symptoms of depression that you’re sad, you're blue, you’re feeling down, you’re lacking in energy, you’re procrastinating, you may socially withdraw or socially isolate oneself, feel less creative, feel helpless, hopeless, worthless, and may even have suicidal ideation.” 

Both men and women can have SAD, but it is more common in women and occurs more in adults than in children.  The disorder is more prevalent in the months of December, January and February when the hours of sunlight are shortest.  Zec explains some treatment options.

“Those who specialize in the diagnosis and treatment of seasonal affective disorder favor proper administration of what’s known as bright light therapy, and there are specially designed lights that deliver a more intense light.  These are not lights that you stare into, but there are lights that you might do some work by in the morning for a half hour or an hour, and then perhaps also in the evening.”

Zec says exercise such as taking a walk in the bright sunlight also can be helpful.  If individuals suffer from seasonal affective disorder and are not helped by bright sunlight and exercise, they should see their physician for evaluation and possible treatment.

Ruth Slottag