When I was living alone for a few years I would speak out my thoughts rather than in my head. That lead to having conversations with my self and then having conversations with fictional characters. I think also being alone increased anxiety and heightened sense of fear. I always wondered if this would have lead to a form of schizophrenia in the long term if I kept living alone.
I agree with the paranoia thing. I've learned to curb that with developing a mentality of "rolling with the punches, but trying to be prepared for them."