Psychology in Cinema

Dissociative identity disorder (DID), previously known as multiple personality disorder (MPD), is a mental disorder on the dissociative spectrum characterized by at least two distinct and relatively enduring identities or dissociated personality states that alternately control a person's behavior, and is accompanied by memory impairment for important information not explained by ordinary forgetfulness. These symptoms are not accounted for by substance abuse, seizures, other medical conditions, nor by imaginative play in children. Diagnosis is often difficult as there is considerable comorbidity with other mental disorders. Malingering should be considered if there is possible financial or forensic gain, as well as factitious disorder if help-seeking behavior is prominent. (from Wikipedia)

John Forbes Nash, Jr. (born June 13, 1928) is an American mathematician whose works in game theory, differential geometry, and partial differential equations have provided insight into the factors that govern chance and events inside complex systems in daily life. His theories are used in market economics, computing, evolutionary biology, artificial intelligence, accounting, politics and military theory. Serving as a Senior Research Mathematician at Princeton University during the latter part of his life, he shared the 1994 Nobel Memorial Prize in Economic Sciences with game theorists Reinhard Selten and John Harsanyi.

Edward Norton – The film’s unnamed protagonist. Suffering from insomnia, he tries various methods to aid his sleep until a chance bar fight inspires the eponymous “Fight Club”, which helps him.

...also called schizophrenia, paranoid type is a sub-type of schizophrenia as defined in the Diagnostic and Statistical Manual of Mental Disorders, DSM-IV code 295.30. It is the most common type of schizophrenia. Schizophrenia is defined as "a chronic mental illness in which a person loses touch with reality (psychosis)” 

Meat Loaf – Bob is one of the other group members in the Narrator’s self-help classes. Having abused steroids in the past, Bob has large male breasts, causing him great anxiety. He joins fight club as a form of release, later being shot by a policeman when the club morphs into an anarchist group. Bob is turned into a martyr by the group’s other members.

Brad Pitt – The protagonist’s imaginary friend, Tyler is an idealised version of himself, displaying all the qualities of masculinity and mental aptitude that the narrator wishes he possessed.