What is SAD?

Seasonal affective disorder is a type of depression that is related to changes in seasons. It usually begins with less hours of sunlight in the fall and eases in spring when days gets longer. Interestingly, a small proportion of people do experience SAD in the summer. Due to the seasonality of SAD, it is commonly known as seasonal depression. Although anyone can get SAD, women experience it four times more frequently than men. At this point, it’s unclear why women are more at risk for SAD than men. Since the disorder is caused by changes in day length, the further away from the equator you live, the higher the risk of experiencing it.

 How many people have it?

Studies indicate that as many as 20% to 40% of people living at approximately the same latitude as Michigan experience some degree of SAD in the winter. However, this number could easily be reduced through lifestyle adaptations, including spending more time outside and using light therapy.