I can understand where you're coming from, I think. Tell me if I hit anywhere near the mark with my own musings?

The decision rests on many many factors, but if independence is important to a given person, it's probably easier to maintain that w/ the (moderate) mental illness. I mean, you can't will away depression, but you can (sometimes) will yourself to work and function despite it. If something actually compromises your ability to breathe, walk, etc., then there is absolutely no question about it: you'll need to rely on others sometimes. That situation also means a significant investment of time and money. If hospital stays are involved, it's probably going to add up to a lot more than even weekly therapy/several prescription psychiatric drugs.

But I'm a person who doesn't value independence super highly, at least not so far in life. Also, some of my biggest issues with mental illness involve shame and embarrassment. And I have a high tolerance for physical pain, so much that I often fail to notice when superficial injuries occur. Add that I don't mind doctors/clinics/hospitals much. (I had a fair bit of physical illness as a child, and I was always just neutral about it.) Because of all that, I think I would prefer the physical ailment. At least then I could tell people and not feel ashamed.