Seasonal affective disorder (SAD) is a mood disorder subset in which people who have normal mental health throughout most of the year exhibit depressive symptoms at the same time each year, most commonly in the winter. People may sleep too much or have little energy. The condition in the summer can include heightened anxiety. In the Diagnostic and Statistical Manual of Mental Disorders DSM-IV and DSM-5, its status was changed. It is no longer classified as a unique mood disorder but is now a specifier, called "with seasonal pattern", for recurrent major depressive disorder that occurs at a specific...