Psychological horror is a subgenre of horror and psychological fiction with a particular focus on mental, emotional, and psychological states to frighten, disturb, or unsettle its audience. The subgenre frequently overlaps with the related subgenre of psychological thriller, and often uses mystery elements and characters with unstable, unreliable, or disturbed psychological states to enhance the suspense, drama, action, and paranoia of the setting and plot and to provide an overall creepy, unpleasant, unsettling, or distressing atmosphere.
Psychological horror usually aims to create discomfort or dread by exposing common or universal psychological and emotional vulnerabilities/fears and revealing the darker parts of the human psyche that most people may repress or deny. This idea is referred to in analytical psychology as the archetypal shadow characteristics: suspicion, distrust, self-doubt, and paranoia of others, themselves, and the world.
The genre sometimes seeks to challenge or confuse the audience's grasp of the narrative or plot by focusing on characters who are themselves unsure of or doubting their own perceptions of reality or questioning their own sanity. Characters' perceptions of their surroundings or situations may indeed be distorted or subject to delusions, outside manipulation or gaslighting by other characters; emotional disturbances or trauma; and even hallucinations or mental disorders. In many cases, and in a similar way as the overlapping genre of psychological thriller, psychological horror may deploy an unreliable narrator or imply that aspects of the story are being perceived inaccurately by a protagonist, thus confusing or unsettling the audience and setting up an ominous or disturbing overarching tone. In other cases, the narrator or protagonist may be reliable or ostensibly mentally stable but is placed in a situation involving another character or characters who are psychologically, mentally, or emotionally disturbed. Thus, elements of psychological horror focus on mental conflicts.