Not many people understand chronic depression. I doubt anything I write here will solve anything, but I think it's important that people recognize the signs of depression and learn to recognize them in themselves and their loved ones.
Most people make the mistake of confusing depression with depression. See, I've just done it myself. One problem for English speakers is that the word for depression (as in a chronic life-threatening mental illness, most often inherited) with depression (as in being sad for a few weeks due to a known cause).