It's related exclusively to other people, and sufferers view all other humans as potential threats who may at any point, for no reason, hurt or demean them. But the reality of a particular kind of personality disorder is a more complex one: paranoid personality disorder (PPD) isn't related to delusions about aliens or malevolent secret 'forces' in the world.
Our concept of 'paranoia' from films and television is centered around usually-comedic characters who think people are poisoning the water or reading their minds.
