This is a very wide question which deserves an equally wide answer. To begin however, there are some myths regarding depression which need to be entirely laid to rest. While it is very true that there are various types of depression (endogenous, exogenous, manic and so forth), it is an absolute myth that there are “types” or treatment for each one. Sadly the Internet is responsible for a lot of this and it is a shame, because people who do want a genuine answer tend to walk away with the wrong one. Suffice to state that while you may diagnose a patient with manic depression (now more fashionably known as “bi-polar depression” and can I please state here and now that this is not simply somebody who feels happy one day and sad the next - that is called “normal”), it would be wrong to believe that you can only treat this patient with lithium. There are many approaches and this is the point.