Depression is a common condition with a lifetime risk of 8.12% in males & 20-26% in females. It may be mild, moderate or severe. The risk of severe depression in a lifetime is about 8%. Clinically, significant depression is often referred to as major depressive disorder (MDD). It is major cause of suicide and disability. It is difficult to differentiate it from a medical condition because it has somatic as well as psychological symptoms.
The typical depression episode is characterized by significant loss of appetite resulting in weight loss, early morning awakening, loss of interest, loss of reaction to pleasant happenings, withdrawal from friends and family, anger, anxiety, loss of concentration, feelings of guilt, pessimism, thoughts of suicide and/or lack of enthusiasm.
Depression associated with a medical condition aggravates any associated disability, diminishes adherence to medical treatment and may even shorten one’s life span.
Bipolar mood disorder is a relapsing mood disorder which may involve periods of major depression mixed with periods of high mood and activity. The relapse rates are very high, though patients seems perfectly normal between the episodes.