How are depression and chronic depression different?

Common language?: It sounds like your question uses some common language to describe a specific disorder. Depression (really major depression) can be determined to be a single episode (with no prior history of these symptoms). Chronic depression is characterized by multiple episodes or called major depression, recurrent).

Chronicdepression: Depression is defined as several symptoms over a 2 week period. Chronic depression or dysthymia is a lower level of depression symptoms which have been present for a 2 year period. The treatments are similar but the long term course can vary. If you have had significant depression symptoms for over 2 years consult a psychiatrist.