Major depressive disorder (also known as recurrent depressive disorder, clinical depression, major depression, unipolar depression, or unipolar disorder) is a mental disorder characterized by an all-encompassing low mood accompanied by low self-esteem, and by loss of interest or pleasure in normally enjoyable activities.

The term “major depressive disorder” was selected by the American Psychiatric Association to designate this symptom cluster as a mood disorder. The general term depression is often used to denote the disorder. Major depression is a disabling condition which 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 commit suicide, and up to 60% of people who commit suicide have depression or another mood disorder.

Look at the following statistics:

2003 National Comorbidity Study, sponsored by the National Institutes of Health says 16% of the population that is nearly 35 million Americans suffer from severe depression.

National Institute of Mental Health indicates that 19.1 million Americans and of age group 18 to 54 years-old suffer from anxiety disorders.

National Institute of Mental Health also says that 9.5% of the adult population that is nearly 18.8 million American adults suffer from clinical depression.