Depression, depressed mood, or painful, perhaps as an independent disease or a manifestation of many other disorders, such as nerve, and somatic. Low mood and can be perfectly healthy people.
Depression - is, first of all, a reaction to the loss. The loss of a loved one, a break with the native people, the loss of work for fitness programs
... However, it may be a loss of faith or loss of former self. Such a condition often in teenagers: you suddenly start teasing at school; you were an only child, and now you appear younger brother or sister, and so on.
Depression is one of the most common diseases and, incidentally, one of the most successfully treatable mental disorders. One in four women and one out of ten men at least once in their lives need professional assistance in connection with the depression occurred. 90% of people seeking help for depression, completely cured