A term I believe was coined by Anton Le Vey, author of "the Satanic Bible". It is used to describe people who feed off of other people emotionally. The Satanic Bible points out how when you must constantly endure the verbal self pity of others in their attempt to induce your sympathies for them, you begin to feel tired and depressed.

Another source..a FAQ on *spit* Vampires, floating around somewhere on the internet had a bit more of a dramatic view of things. They try to make psychic vampires "Magical Creatures" and even go as far as making them into evil spirits. I think thats a rather moronic view. Chronic whiners are not magical. Here is an excerpt:

"A psychic vampire is a living person who "drains" others emotionally.
Depending on the version, this may be an empathic drain (i.e., literally feeding on the emotions or 'life-force' of others) or it may be a metaphorical drain (someone who "takes" emotionally without giving anything back; a "user"). The victims of a psychic vampire become lethargic and depressed, and, should they be drained too much, may become suicidal.
The psychic vampire itself is generally represented as fairly normal except for its ability; depending on who you ask, psychic vampires may or may not be aware of what they do, and along the same line, they may feed in different ways. It has been described by some as reaching out with your astral self to tap into a living person and draining them of their energy and then transforming, or processing, that gained energy into life force of some sort. Others say that they reach out with their aura and leech away energy from the auras of other people. Like many things, it depends on who you talk to and what their experiences have been. There is no way of telling who is right and who is wrong, and there is the possibility that all of them are right and they merely feed in different ways."

If you pick out the crap, it has some valid points.