Do you have a tendency to become depressed around the same season every year? If so, it may be due to seasonal affective disorder. Many people experience the effects of SAD during the winter months, though it can occur during any season.
It is believed that the main cause of SAD is a diminished amount of exposure to sunlight, though research continues to bring further developments.
SAD afflicts women and younger people more, as well as those with a family history of depression, and who live far away (north or south) from the equator.
