I believe, and this is just a belief that there are two types of depression. One is called situational depression which has a clear reasonable cause ie a loss of job of a career, or a loss of a loved one. Then there is the type that many of us have which makes you sad with no energy when there is no logical reason for us feeling that way.

I agree and the second type of depression you mentioned the one that is not situational I believe from what I've read but then again I'm not a doctor it's due to the chemical imbalances in the brain and that is the one that I believe cannot be cured just managed by therapy and or medicine. I hope this didn't violate any of the guidelines site I'm not very good at those but situational depression is often able to either get better or go away from what I've heard again I'm not a doctor

My previous Psych.,the best Dr. I've ever had, said my condition (Bipolar 1) would be with me my whole life and that I would probably have to be on meds. my whole life as well.

Yes I had doctor told me same thing I guess though with some people may only be a temporary thing.