Tried it once on a different forum. Except a lot of people couldn't seem to detect it cause I was using an unreliable narrator, my character, and everything was from his point of view. I guess my writing wasn't up to par to make people think in the back of their minds that my character wasn't 100% in the mind. I tried to make a Don Quixote-esque character who was suffering from schizophrenia and from delusions/grandiose delusions. However, I tried to make the delusions seem natural and a bit realistic while leaving some small red flags here and there such as reoccurring "NPCs" conveniently showing up one moment and practically disappearing the next. How would you guys try to create a sense of unease and make readers question if the narrator is reliable or not in terms of psychological issues without being obvious?