Seasonal Affective Dissorder (SAD)

By Josepha Cheong, M.D., Michael Herkov, Ph.D., Wayne Goodman, M.D.
20 Nov 2000
Seasonal Affective Disorder (SAD) is a type of depression that typically occurs in the fall and winter, when days are shorter and provide less sunlight.

Depressive symptoms begin in the fall or winter and persist until the spring.

People suffering from SAD either are unable to function or function minimally during the season in which their disorder occurs.

SAD shares several symptoms with other forms of depression including lethargy, sadness, hopelessness, anxiety and social withdrawal.

SAD sufferers crave additional sleep, experience daytime drowsiness, and gain a good deal of weight, often feeling irresistible cravings for sweets.

Four to six percent of the general population will experience SAD. Women are four times more likely than men to develop SAD.

SAD is more common among the young (ages 20 to 50) with a general decrease in symptoms with age.

Risk of the disease increases significantly with geographic residence (with increased prevalence at higher latitudes). For example, the incidence of SAD among people living in Florida is 1 percent, while those living in northern latitudes, such as Alaska or New Hampshire, have a rate of approximately 10 percent.

Treatment for SAD typically involves a combination of daily light therapy and medication. Exercise and stress management also help to lessen the symptoms of SAD.