causes:

1. Depression is a natural response,with its disappointments, relationship problems and stress.
2. Depression beyond understandable limits is thought to have a largely biochemical cause. depression considered mainly biochemical in orgin is called "endogenous or psychotic "depression.
3. Depression is sometimes the expression of an underlying problem -ALCOHOLISM.depression in young people can occur because of early SCHIZOPHRENIA.
4. Rarely,depression can result from brain disease,such as pralysis or epilepsy.    

SYMPTOMS:

1. depressed individuals get no enjoyment out of life.they feel sad and may tell others how sad they feel.
2. As depression deepens they cry more easily and are increasingly preoccupied by death,decay or bad events.
3. physical symptoms,severly depressed people neglect themselves and lose their appetite. 

TREATMENT:

1. Best way is to give them a psychological support.
2. Drug therapy,it reduces depression and suicide risk rapidly.This treatment is continued for six to twelve months on average.
3. Nutritional therapy,try supplementing B vitamins.reduces the common drpressions.
4. Batch flower remedies-trying mustard if the deprssion comes for no apparent reason may reduce the deression