This document discusses the history and key characteristics of psychological thriller films over several decades from the 1950s to the 2000s. It provides examples of influential psychological thriller films from each decade that helped define the genre, such as Rear Window (1950s), Psycho (1960s), and The Mist (2000s). Common elements of psychological thrillers are discussed, including an emphasis on the protagonist's mental state over plot and a threat stemming from mental rather than physical danger.