The black background and red text stands out immediately and shocks the audience, these colours are associated with gruesome things which gives the film a horror feel.
The opening scenes are edited so there are shorts, shocking clips in between the credits in text. The clips make the whole opening sequence look broken and fragmented which represents society and peoples emotions at this time in the film, this all contributes to the audiences knowledge of the kind of horror film this is. Also the clips vary from being played at a fast pace to a slow pace, which builds up tension and almost gives an adrenaline rush feel.
In addition to this with regards to mise en scene, the majority of the costume are ripped clothes and dark colours which suggests to the audience the film is quite violent and associated with death.
The fact that a hand held camera is used shows use of cinematography to create a state of panic as the camera is constantly jaunting. Also the shots are sometimes unclear because of this which creates mystery for the audience as they cannot always see what is happening yet they know it is something bad which creates tension.
Diegetic sounds of screaming and are used which also builds up tension when the audience cannot see what is happening. Screams of terror are often used in horror films to show emotion. Contrastingly, slow music is played in the background, this use of non diegetic sound is used to build up tension. The fact that slow music and flashes of clips are played together, builds up a sense of panic.
Also the heart rate monitor makes the audience associate the film with life and death and what is in between which represents the theme of the film. The colour red is also associated with blood which all relates to horror.
In the opening scenes of the horror film American Psycho cinematography, editing, mise en scene and sound show how the genre is introduced to the audience.
The slow pace of editing makes the sequence seem really sinister as it is mixed with the diegetic sound of him talking in a slow, low tone voice contrasts with the things he's talking about as they turn from OCD-like, perfectionist things to violent, psycho things.
Cinematography is used to zoom in slowly to a close up of his face, which creates intensity and forces the audience to view his perfection. Also the dull colours with a splash of red at the side makes the audience relate to blood and the fact that he might be violent, if not we just get the feeling that something is shocking.
Also a wide angle close up is used to force the audience to focus on how obsessive he is about his appearance which makes them realise its actually not normal. The peeling off the mask represents how he is perfect on the outside but not right on the inside and this is confirmed when he confesses later in the narrative.
The use of narrative tells the audience he is proud of what he does and when he talks about bloodlust as if it is a normal thing the audience know this is a horror/thriller film.
With regards to mise en scene the audience can tell the character is average as he wears normal clothes, we do not see anything abnormal apart from his obsessive morning routine, this builds up tension as it contrasts with the title of the film, the audience are waiting to see something psycho in him.
The whole opening sequence is a juxtaposition as the normality of his voice, looks and actions contrasts with the violent things he says he likes.