In the movie "Fight Club," the character Tyler Durden, portrayed by Brad Pitt, is not explicitly diagnosed with any specific mental illness. However, it is implied that he exhibits symptoms consistent with dissociative identity disorder (DID), previously known as multiple personality disorder.
Dissociative identity disorder is a complex and rare mental health condition characterized by the presence of two or more distinct identities or personality states within an individual. These different identities may take control of the person's behavior and consciousness at different times, leading to gaps in memory and a sense of detachment from oneself.
Throughout the film, it becomes apparent that Tyler Durden and the protagonist, played by Edward Norton, are two distinct personalities within the same individual. The protagonist's dissociation from reality, his lack of awareness of Tyler's actions, and the presence of significant memory gaps suggest the possibility of DID.
It's important to note that "Fight Club" is a work of fiction, and while it offers a portrayal of dissociative identity disorder, it may not be entirely accurate in its representation. Additionally, the character of Tyler Durden is a complex and symbolic figure that serves various roles within the narrative. The depiction of mental health in the movie should not be taken as a clinical or definitive representation of the condition.