2 Answers

Noun
Severe despondency and dejection, accompanied by feelings of hopelessness and inadequacy.
A condition of mental disturbance, typically with lack of energy and difficulty in maintaining concentration or interest in life.

In economics, a depression is a sustained, long-term downturn in economic activity in one or more economies. It is a more severe downturn than arecession, which is seen by some economists as part of the modern business cycle.

Considered by some economists to be a rare and extreme form of recession, a depression is characterized by its length; by abnormally large increases in unemployment; falls in the availability of credit, often due to some kind of banking or financial crisis; shrinking output as buyers dry up and suppliers cut back on production and investment; large number of bankruptcies including sovereign debt defaults; significantly reduced amounts of trade and commerce, especially international; as well as highly volatile relative currency value fluctuations, most often due to devaluations. Price deflation,financial crises and bank failures are also common elements of a depression that are not normally a part of a recession.

http://en.wikipedia.org/wiki/Depression_(economics)

A constant feeling of sadness, anxiety, and general feeling of pessimism sets in (the glass is always half empty)The person feels hopeless Individuals can feel restless.The sufferer may experience irritability.Patients may lose interest in activities or hobbies they once enjoyed.He/she may lose interest in sex of energy feel lower, fatigue sets in.Many people with a depressive illness find it hard to concentrate, remember details, and make decisions Sleep patterns are disturbed - the person may sleep too little or too much.Eating habits may change - he/she may either eat too much or have no appetite.Thoughts may occur - some may act on those thoughts.The sufferer may complain more of aches and pains, headaches, cramps, or digestive problems. These problems do not get better with treatment.

Source :http://www.medicalnewstoday.com/articles/8933.php