For my film students, a list of films to see if you are interested in this particular genre.

Psychological thrillers are a subgenre of thriller. They are defined by their story potentially occurring solely in the protagonist's head: the protagonist becomes an 'unreliable narrator', and we don't know if what we are seeing is real.

Generic conventions: all is not as it seems. Twists, reveals. A character who doesn't exist.
Audience emotion: tension, suspense, shock.

Please feel free to suggest others.