Depression is as much a clinical fact as influenza, arthritis or a peptic ulcer. In most cases the depression is very mild and soon passes. In a few cases there may be a need for treatment. What is known as 'bipolar illness' or 'manic depression' refers to the more severe variety. A large number of people suffer from mild depression.
Now it may be that no one will want to acknowledge depression because it may be seen as a sort of stigma and a barrier to promotion. At the same time it is useful to have a code which allows someone to acknowledge depression in a straightforward manner.

This particular code may even be more useful in domestic and non business situations than in business. Once again, the code signals that the mood is real but that it is not the fault of anyone.