Major depressive disorder (
MDD) (also known as
clinical depression,
major depression,
unipolar depression, or
unipolar disorder; or as
recurrent depression in the case of repeated episodes) is a
mental disorder characterized by a pervasive and persistent
low mood that is accompanied by low
self-esteem and by a
loss of interest or pleasure in normally enjoyable activities. The term "depression" is used in a number of different ways. It is often used to mean this syndrome but may refer to other mood disorders or simply to a low mood. Major depressive disorder is a disabling condition that adversely affects a person's family, work or school life, sleeping and eating habits, and general health. In the United States, around 3.4% of people with major depression die by
suicide, and up to 60% of people who die by suicide had depression or another mood disorder.