Gale Encyclopedia of Alternative Medicine:
Depression, also known as depressive disorders or unipolar depression, is a mental illness characterized by a profound and persistent feeling of sadness or despair and/or a loss of interest in things that were once pleasurable. Disturbance in sleep, appetite, and mental processes are a common accompaniment. Everyone experiences feelings of unhappiness and sadness occasionally. However, when these depressed feelings start to dominate everyday life without a recent loss or trauma and cause physical and mental deterioration, they become what is known as depression. Each year in the United States, depression affects an estimated 17 million people at an approximate annual direct and indirect cost of $53 billion. One in four women is likely to experience an episode of severe depression in her lifetime, with a 10-20% lifetime prevalence, compared to 5-10% for men. The average age a first depressive episode occurs is in the mid-20s, although the disorder strikes all age groups indiscriminately, from children to the elderly.
