I'm looking for an alternative for "paranoid/paranoia" that doesn't relate to mental health.
For use in the context of games, movies and other media that seek to induce a sense of fear and vigilance. Media where a threat, implied or real, keeps the viewer on their toes, forcing a state of constant vigilance and second-guessing.

The word "paranoid" always pops up, and I don't want to use that term.