Major depressive disorder, commonly referred to simply as depression, was a mental disorder characterized by an all-encompassing low mood accompanied by low self-esteem, loss of interest and/or pleasure in normally enjoyable activities and lack of energy. Depression could be caused by many things, including having a bad life, loss, abuse, and remorse; remorse being the most prominent feeling that lead to depression. Depression led to suicidal tendencies, though it only rarely led to murder.