Adrenochrome is produced from adrenaline. People make their own adrenaline and adrenochrome when excited. That's why people do thrilling things. Torturing screaming children would certainly get the juices going internally. But eating adrenochrome would not be efficient intake because it would tend to be digested before it got in the bloodstream, plus even a whole tortured baby would hardly have enough to move an adult. I don't doubt people do drink blood and think it has special magic powers: I believe it's an ancient problem and why Jehovah had a lot to say about not eating blood, it was an effort to stop this sort of thing. However, I also believe that the adrenochrome rush is self-created and the belief that it's from consumed blood is an illusion.