Psychological

Psychological horror puts the monster inside the skull. The haunting may be real or the narrator may be unwell, and the film sits in that ambiguity for as long as it can hold it. Where a slasher gives you a killer to watch for, this form gives you a person to watch, and asks you to notice the moment they stop being reliable.

The defining move is doubt. The protagonist is under pressure, from grief, isolation, guilt, ambition or illness, and the film shows the world through them while that pressure bends it. You are never quite sure what is a threat and what is a symptom. The form prizes atmosphere over incident and tends to be a slow burn by design, because the fear is about erosion.

The modern form starts with Psycho (1960), which split its horror between a killer and the mind that made him, and with Roman Polanski, whose Repulsion (1965) and Rosemary's Baby (1968) made two apartments into the most frightening rooms in cinema. The Shining (1980) is the form's cathedral: a hotel, a family, a slow descent that the film never fully explains. Jacob's Ladder (1990) brought it to Vietnam veterans, and Audition (1999) and Cure (1997) to Japan, where Kiyoshi Kurosawa made hypnosis and suggestion into a kind of plague. Black Swan (2010) took the form to the ballet and the Academy Awards. The 2010s produced a run of grief and dread films, The Babadook (2014), It Follows (2014), The Invitation (2015), Hereditary (2018), Saint Maud (2019), and the industry started calling them elevated horror, a label the films did not ask for. Split (2016) showed the form could still be a thriller, with a mind as the monster and a basement as the set.

The signature techniques are intimate. The camera stays close to one face. The sound design slips, so you hear what the character hears, including things that may not be there. Mirrors do not quite agree. Sets subtly change between scenes. And the ending refuses to settle the question, or settles it in a way that makes everything before it worse.

Supernatural horror is the nearest neighbor; many of the best films on this page could be filed there, and the ambiguity is the point. Haunted houses is where The Shining lives when you decide the hotel is real. Body horror overlaps when the mind doubts the flesh, as in Black Swan. Serial killers share Psycho and Split, where the mind is the monster. Cults share the grief-driven revival through Midsommar (2019), and home invasion is the opposite pole: no ambiguity at all, just a door.

For deeper cuts, try Cure (1997), Kiyoshi Kurosawa's film about a detective and a young man who cannot remember anything, which spreads murder like a cold. Repulsion (1965) leaves a woman alone in a London flat for a weekend while the walls start to crack, Polanski's first horror and still the purest film about a mind closing in on itself. And Perfect Blue (1997) follows a Japanese pop idol who turns to acting and loses track of which life is hers, animated, and no less frightening for it; it predicted the internet.