I think it depends on why you are self disclosing.
If it's to let another person know where you've been and who you are, you really aren't risking as much. if you're making yourself vulnerable and asking for acceptance, you are risking rejection.
I had quite bad depression (set off by pnd) when I first gave birth to Beth. I wasn't myself, had lost the ability to edit, was really all over the place and damaged in ways I couldn't even articulate or understand myself.
I had two best girlfriends at the time who, if you'd asked me prior, I would have said would stick by me and get me through anything.
As it happens I was wrong, and they not only walked away, but openly and brutally rejected me first when all I really needed was them to keep faith in me and wait it out. It broke my heart and sent me spiralling.
I can reveal this here because I have nothing invested and there really is no one to reject me. Revealing my blackest side to the people I thought loved me best at the time left me crushed.
Now that I've come through what I have (as much as anyone, anyway) I have no qualms imparting my knowledge or perspective, but only if it's in context or if I think I can be of use to someone else. But again, those situations don't come up organically very often in my day to day life.
Does that make sense?