Major depressive disorder 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 which is accompanied by low self-esteem and by a loss of interest or pleasure in normally enjoyable activities.
Major depression significantly affects a person’s family and personal relationships, work or school life, sleeping and eating habits, and general health. Its impact on functioning and well-being has been compared to that of chronic medical conditions such as diabetes.