Genre research - psychological thriller

Psychological thriller is a specific sub-genre of the broad ranged thriller with heavy focus on the unstable emotional states of characters, in combination with mystery and thriller. However, it often incorporates elements from the mystery and drama genre, along with the typical traits of the thriller genre. In addition to drama and mystery, many psychological thrillers contain elements of, and often overlap with, the horror genre, particularly psychological horror.
Psychological thriller – Characters are no longer reliant on physical strength to overcome their brutish enemies (which is often the case in typical action-thrillers), but rather are reliant on their mental resources, whether it be by battling wits with a formidable opponent or by battling for equilibrium in the character's own mind. The suspense created by psychological thrillers often comes from two or more characters preying upon one another's minds, either by playing deceptive games with the other or by merely trying to demolish the other's mental state
http://en.wikipedia.org/wiki/Psychological_thriller

Is more mentally based, relating to mind processes but focuses on the plot more than the characters.

Themes: Reality, mind, perception, death, identity, existence and black comedy.
These major subgenres help develop the plot of a psychological thriller film, shaping the characters' personalities. e.g. usually character will find the true identity/the devil side of himself/herself in psychological thriller, in which it is one of the archetypes—the loss of innocence.
Two characters usually mess with each others heads and play mind games on each other.

Low key lighting, very tense music and black and white shots(to make shadows stand out) would be an ideal.

Here are a few examples of psychological thriller films The Inside, Don't Say A Word, and A Beautiful Mind.



Here are a few examples of psychological thriller posters Shattered Soul,Orphan, and Abandoned.