> We need another word for what is described above. Most people understand ordinary depression, because most people feel down sometimes

No we don't, it's called depression.

What we need is people to realize that depression is not 'people feel down sometimes.' That is feeling down. Depression is not something that you just work through, it is an actual, real thing going on in your brain.

But hell, most people act like armchair psychologists so ya, lets create another term that they'll also misuse.