Seasonal Affective Disorder (SAD):SAD is a type of depression that typically emerges as the days shorten during the fall and winter months. It is thought that people with SAD have negative reactions to the reduced daylight and cooler temperatures as these seasons advance. The symptoms of SAD are characterized by recurring depressive symptoms, such as overeating, excessive sleeping, and weight gain, specifically during the fall and winter. Individuals with SAD usually experience a complete recovery from depression during the spring and summer, without any episodes unrelated to the seasons. A strong desire for sugary or starchy foods is also often associated with SAD, distinguishing it from other types of depression.Seasonal Affective Disorder has only recently been recognized as a medical condition, with the term first appearing in print in 1985. It is also sometimes referred to as winter depression or the hibernation reaction.