Clinical depression, also known as recurrent depression, major depressive disorder, or unipolar depression, is a disorder characterized by repeated episodes of depression without any history of independent episodes of mood...
Disruptive mood dysregulation disorder, major depressive disorder, persistent depressive disorder, and premenstrual dysphoric disorder are categorized under depressive disorders in the fifth edition...
During pregnancy, depression can occur prenatally (anytime from conception to birth), during peripartum (the last month of gestation to first few months of delivery), or postpartum (from delivery, up to a year after birth).