I suffer from clinical depression, mostly in remission now. I will never be rid of depression, it will always lurk in the background. Depression can still lay me low without enough energy to get out of bed or even eat. It can still trigger self destructive behavior like smoking and drinking to excess. What has changed is now my depressive episodes last hours or a day at most. They used to last for weeks.
It's taken a lot of therapy (thank you Dr. Cooper) and work to get to this point but I have managed to avoid anti-depressants. For those who are on anti-depressants and whom they help, good for you and I wish you the best.
Depression is a very real, debilitating and sometimes fatal illness. No one in the grip of a depressive episode wants to hear 'get over it', 'pull tour self together', 'turn that frown upside down' or any of the many variants of these. Believe me if we could just pull our selves up by our bootstraps we would. We can also mange our illness so we don't need to be treated as useless and fired or not hired because of it.
In the meantime I live with my depression knowing anything or nothing at all can trigger a depressive episode. As Christine Smith says, for us pessimism is easy, it's optimism that's hard.