@biteme Very detailed analysis and not boring at all.

When it comes down to it, vampires like all monsters, are really useful as screens on which people can project their particular fears, and as those fears change over time. While mental illness has certainly been a fear for many people & still is, I don't think personality disorders are what most people think of in those terms. And I don't think the vampire was a very useful figure for those particular fears. Mr. Hyde certainly represents a fear of mental illness, but he isn't really very schizoid--maybe manic and certainly sociopathic.
True, I think a lot of the motivation behind literature (as well as other art forms) is a way to sublimate fear and put it in a format in which it can be more easily understood, controlled, sort of a way of facing one's fears so that the fears lose power.
I think the vampire has probably represented different things over time. As Exempt said, in the current times it seems to represent addiction.
I also agree with Bewitched that it does seem to align more with BPD now that I think about it more, well, maybe not BPD per se, but with a desire to possess a person, their body and soul, if you will. Which probably comes from fear of abandonment.
As Mobzie said, a lot of people seem to associate vampires with people who are driven and charismatic. I hadn't had that association, myself. I think of them as reclusive and secretive, but people can interpret art and literature in different ways, I suppose. Perhaps projecting some of their own psychological traits onto the characters, or "monsters" ? (especially if those psychological traits are suppressed)
I may be wrong, but I believe the story of the vampire has been around since biblical times. The origins of the vampire were the children of Cain, were they not? So they seem to represent outcasts. At least, from my own interpretation they seem to represent that.