The biggest issue IMO, is that someone who is mentally ill or depressed can just snap or have a breakdown one day. One day you were married to Rochel, today you’re married to a completely different person. Is that a risk you are willing to take? If so, go ahead. It’s easier to deal with a physical health issue, where the person would mentally be the same, having a great personality after reflecting on life more than others. With a mental health issue, if the problem perks up, the marriage could easily be in shambles, at best.
I was asked about going out with a rich beautiful perfectly religious girl, with a great family. Though mental illness runs strong in the family. I said no, though it was a hard no to say.