In psychology, some characters are known to drain other people's vital energy, amongst others the narcissists, who often still find willing victims, co-narcissists, which is often shown in the so-called drama relationships, but also in professional life, such dependency relationships between boss and subordinates arise.
In occultism such energy-consuming people are called energy or psychic vampires and this single is about these people.
The text used here is a passage from Anton LaVey's "Satanic Bible", which reads as follows:
"Many people who walk the earth practice the fine art of making others feel responsible and even indebted to them, without cause. Satanism observes these leeches in their true light. Psychic vampires are individuals who drain others of their vital energy. This type of person can be found in all avenues of society. They fill no useful purpose in our lives, and are neither love objects nor true friends. Yet we feel responsible to the psychic vampire without knowing why." -- Anton LaVey
I'm not a Satanist or occultist, but as Timothy Leary said: "Science is all metaphor", you can find useful information in occultism too.
If you want to know more about these so-called psycho or energy vampires, you will find enough information on the net. A reasonably scientific source would be for example Dr. Judith Orloff at the "Semel Institute for Neuroscience and Human Behavior" of the University of California, Los Angeles (UCLA) and at her blog "What is an Energy Vampire?" or the category for energy vampires, unfortunately only in English. It goes without saying that you shouldn't just believe everything there either, at least for me.