<unk>  <unk>  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 winter. Common symptoms include sleeping too much, having little to no energy, and overeating. 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<unk>  pattern", for recurrent major depressive disorder that occurs at a specific time of the year and fully remits otherwise. Although experts were initially skeptical, this condition is now recognized as a common disorder. However, the validity of<unk>  has been questioned by a 2016 analysis by the Center for Disease Control, in which no links were detected between depression and<unk> ity or sunlight exposure. Video explanation In the United States, the percentage of the population affected by<unk>  ranges from 1.4% of the population in Florida, to 9.9% in Alaska.<unk>  was formally described and named in 1984 by Norman E. Rosenthal and colleagues at the National Institute of Mental Health.
Seasonal affective disorder
Major depressive episode
Major depressive disorder
Depression 
Late life depression
Premenstrual syndrome
Secondary mania
Postpartum depression