Seasonal Affective Disorder
Seasonal affective disorder (SAD), also known as winter depression or winter blues, is a subtype of mood disorder consisting of recurrent major depressive episodes of varying severity, which occur with a seasonal pattern. The most common type of SAD is winter depression with symptoms beginning in autumn and winter. This is followed by full remission or hypomanic states (mild state of mania) during the following spring and summer.1 A rare form of SAD occurs during the summer.