The Facts
Seasonal affective disorder, or SAD, is a type of depression that seems
to be related to the amount of daylight to which people are exposed. For
most people it tends to be worse in the fall or winter, making it an extreme
form of the "winter blahs."
Every year, as the days get shorter and the weather gets colder, it is estimated
that millions of Americans are affected by SAD. About one third of those affected
have actual SAD and the other two thirds have some symptoms of SAD or "winter
blues." It is three to four times more common in women than in men and
it usually begins when people are in their twenties. Older people are at lower
risk. Children can also experience SAD, although it is far less common. Some
will outgrow it, but it may also last a lifetime.