A negative person is taxing to any normal person, much more with folks with their own serious concerns. I had a friend once who just wore me out when we went out to eat with all her worries. I could feel down for days; I eventually shed my dependent friend, because I needed my emotional strength for my myself as those near and dear to me.

I think they can suck you into their worries and trying to solve their problems, when many times you need that concentration somewhere else. Any solutions i might offer this person went unaccepted and that is really infuriating. Especially if the answer was as clear as the nose on her face. I think she was just high into attention getting.
Don't know if that is what you have in mind or not. hugs, bj