http://www.psychologytoday.com/blog/the-introverts-corner/200911/introversion-and-the-energy-equationThis is interesting, because I've referred to myself, on occasion, as an emotional vampire - and I didn't know that expression was used by other people as well. It's also interesting that the article talks about energy in relation to social interactions, because when I try to explain my problem with social life to people, I often refer to my available level of energy. I usually say I'm a "low energy person" when it comes to social life.
ETA: Actually, I'm a low energy person in general, I think. There is - usually - only very little energy available in my psyche for social relations, and that means I can be a good friend to one or two people - maybe three; or I can be a bad friend to more. There is only so much energy to go around.
"Emotional vampire" is a very negative term of course, and the description makes it sound like a choice: emotional vampires "tend to like a big return but don't like making such a big investment" - "like" and "don't like", not "need" and "can't". Emotional vampires are, in other words, (somewhat) deliberately exploiting other people. Maybe - well, okay, *certainly* - this is true for some people. But, speaking for myself, this is definitely *not* something I do because I "like" it. Rather, it's something that happens because I have an unfortunate need for deep connection paired with an extremely low energy level available for social interactions.
The situation is exacerbated by the fact that, I think, the same description also fits rather a lot of the people I care about. Which means that none of us can fulfill the other's needs. We all need more from the other than we can give. A lot of the time; maybe most of the time. When I've seen a friend or two, or written an e-mail or two, or made a phonecall or two, that - usually - means I've exhausted my social energy reservoir for the week. I have seriously considered making a schedule of some sort, spacing out social contacts according to some rota so that everyone I care about gets at least *some* attention from me, if only at long intervals. Of course, social life doesn't really work that way.
ETA 2: Sorry, no replies to comments today; awfully busy day, just needed to ramble about this for a moment because it seemed so a propos.