What Is Seasonal Affective Disorder and How Is It Treated?

Last Editorial Review: 1/11/2018

Ask the experts

What is seasonal affective disorder and how is it treated?

Doctor's response

Seasonal affective disorder (also referred to as SAD) is a periodic form of depression that tends to occur (and recur) as the days grow shorter in the fall and winter. It is believed that affected persons react adversely to the decreasing amounts of light and the colder temperatures as the fall and winter progress.

While the treatment of seasonal affective disorder can include medications, recent research has found that regular exposure to bright light, particularly fluorescent light, in the morning and evening significantly improved depression in persons with the condition. This form of treatment is referred to as light therapy.

Seasonal affective disorder has not been recognized very long as a medical condition. The term first appeared in print in 1985. Seasonal affective disorder is also sometimes called winter depression or the hibernation reaction.