Psychological thrillers may have similarities to gothic novels and detective fiction in the sense of sometimes having a "dissolving sense of reality". The story is often told through the viewpoint of psychologically stressed or distorted characters, revealing their twisted mental perceptions.
Psychological thrillers frequently focus on the complex and tortured relationships between obsessive and pathological characters. They may incorporate elements of mystery, drama, action, and paranoia.
The genre is closely related to and sometimes overlaps with the psychological drama and psychological horror genres, the latter generally involving more horror and terror elements and themes and more disturbing or frightening scenarios. More on Wikipedia