Rhetorical question that I've thought about also. If you believe that loneliness causes depression, then is it your belief or the loneliness that causes the depression? I've seen the articles on the correlation between loneliness and depression, but I'm not convinced of the causation. This is a video by Noah Elkrief on youtube that's a different take on loneliness. He has a few other videos on loneliness and being single.
Yes, and it's also complicated by the idea that loneliness and being alone are the same thing. In this article, some of the suggested antidotes to loneliness are getting a pet, finding a passion, traveling, altruism, and believing in a higher power. In most of those, other people are optional. Loneliness in that case is tied to how people look at themselves. It's the same with depression. It's not clear to me if one causes the other or if they're the same phenomenon with different labels.