Psychological Thrillers

The conventions of psychological thrillers are:
 - Central Theme Of Identity
Mistaken identity, stolen identity, dual identity, doppelgangers, confused identity.
 - Perception Of Reality 
Seeing the narrative from the perspective of multiple characters. A character having a different perspective of what is and isn't real compared to the norm established in the film.
 - Memory
The torture of an individual with a traumatic memory. The trauma of a specific lost memory.
 - Stream Of Consciousness
This is a device often used in psychological thrillers to give an insight to the psyche of a particular character  - usually the main protagonist.
 - Unreliable Narrator
Psychological thrillers often play on the idea of the inherent trust placed in the narrator or the central character that the narrator follows.
 - Technical Devices
Flashbacks & Repetition is editing is common.
 - Imagery 
Eyes are a frequent motif.