Psycho IV: The Beginning, a 1990 prequel to the first film. — Psycho

"Psycho (1960 film), directed by Alfred Hitchcock."

"Psycho (1998 film), a remake directed by Gus Van Sant."

"Psycho II, a 1983 sequel to the first film (unrelated to the novel Psycho II)."

"Psycho (novel), a 1959 novel by Robert Bloch."

"Psycho II (novel), a 1982 novel by Bloch."

"Psycho III, a 1986 sequel to the first film."