Well, the Alcubierre drive [1] uses negative energy, but at this point it is not clear whether this type of propulsion is just a mathematical gimmick.
[1] https://en.wikipedia.org/wiki/Alcubierre_drive
Besides, all warp bubble metrics so far are inertial; meaning the ship is unable to accelerate, so they're a gimmick nowadays. I have hopes we find something workable though.
Plenty of people believe that mental problems are all caused by disembodied souls unleashed by Xenu of the Galactic Confederation when he blew them up with A-bombs in Hawaii, back when Earth was called Teegeeack.
What "plenty of people" believe is not important.