How is Bromden's schizophrenia depicted in One Flew Over the Cuckoo's Nest?

In One Flew Over the Cuckoo’s Nest, Chief Bromden displays numerous signs and symptoms of paranoid schizophrenia. It’s important to note that the novel does not outright say Chief Bromden is a paranoid schizophrenic because a key theme of the narrative is the ambiguous nature of sanity. This idea is reinforced by the main character and protagonist, Randle McMurphy, who is faking his insanity in order to remain out of prison.

Two indicators of paranoid schizophrenia are hallucinations and delusions. Chief Bromden hallucinates a fog and thinks a snow-like object is falling on his body. He also believes that society is under the control of a massive machine which he refers to as “The Combine.” He thinks that all hospital staff members are willing participants in “The Combine.”

Paranoid schizophrenics also remove themselves from social interactions. Through years of disguise, Chief Bromden has convinced the staff that is he both deaf and mute, which speaks to the length he is willing to go remove himself from society.

Perhaps the most telling sign comes at the end of chapter 1, when he says “But it’s the truth even if it didn’t happen.” This leaves open the possibility that the entire narrative is a hallucination of Chief Bromden’s, as well as tying back to the overall theme of truth and sanity.

How is Bromden's schizophrenia depicted in One Flew Over the Cuckoo's Nest?

In One Flew Over the Cuckoo's Nest, Chief Bromden demonstrates many classic symptoms of paranoid schizophrenia, including delusions/hallucinations and emotional blunting, which are well-detailed in the earlier posts here.

But you are correct in that the novel offers no concrete proof of Chief's insanity. This is intentional, as the story deals with the nature of sanity, and who gets to judge whether a person is "insane." The protagonist of the novel, Randle McMurphy, feigns mental illness to go to the hospital instead of prison. If he can fool hospital administrators into thinking he's insane, it's possible Chief Bromden could have done similarly. At the end of Cuckoo's Nest, the constant fog that surrounds his vision clears, and Chief stops hearing the whir of the invisible machinery of the Combine, which he thinks secretly runs the world.

This could be read as Chief getting "well," as though his sanity had been restored. This would imply that Chief was sane when he first checked into a psychiatric hospital some 10 years ago, and that the system, as characterized by Nurse Ratchett, turned him into a "paranoid schizophrenic."

Because Chief makes the intriguing disclaimer at the beginning of the novel that the story is true "even if it didn't happen," the ending could also be read differently. All or part of the story might be a long hallucination, in which case Chief is definitely insane. The beauty of the novel is that it walks the line, not tipping its hand, and lets readers muse on the interpretation.

How is Bromden's schizophrenia depicted in One Flew Over the Cuckoo's Nest?

Chief Bromden appears to be schizophrenic because he has several of the symptoms that characterize schizophrenia, including delusions, hallucinations, strange motor behavior, disorganized speech, and lack of emotion and social interaction. He has hallucinations that fog is enveloping him. When he is being subjected to electroshock therapy, he thinks, "They start the fog machine again and it’s snowing down cold and white all over me like skim milk, so thick I might even be able to hide in it if they didn’t have a hold on me." He also has delusions that everyone who works in the hospital and in society at large is working for what he calls the "Combine," a giant machine that controls everyone's behavior. Chief constantly hears the hum of the machinery coming from the Combine. In Chapter 1, he refers to the noise of the Combine as the "hum of black machinery, humming hate and death and other hospital secrets." He is socially withdrawn and does not speak, which are also characteristics of schizophrenia. At the end of Chapter 1, he says, "But it’s the truth even if it didn’t happen." He suggests that the entire story he is about to tell might be a long hallucination. 

How is Bromden's schizophrenia depicted in One Flew Over the Cuckoo's Nest?

As defined in dictionary.com, Schizophrenia is "a severe mental disorder characterized by some, but not necessarily all, of the following features: emotional blunting, intellectual deterioration, social isolation, disorganized speech and behavior, delusions, and hallucinations."

First of all, we know Chief Bromden is deaf, but he has chosen for years not to speak a word.  He has maintained this charade for so long that everyone on the ward, both patients and workers, take it as a fact that he's deaf.  This falls under the sympton of social isolation because he purposely excludes himself from all the other patients.

He also has elaborate and frequently occuring hallucinations that the ward is some giant mechanism that makes this at times ear piercing mechanical noise.  The reader can tell he's delusional because nobody notices it but him.

What was Chief Bromden's diagnosis for schizophrenia in One Flew Over the Cuckoo's Nest?

Chief Bromden was diagnosed with paranoid schizophrenia, but whether he truly was mentally ill has been the subject of spirited debate since the book was published more than fifty years ago.

Chief, who narrates the story, describes living in "a fog," and how a deep state-like "Combine" machine secretly rules the world. He has been in psychiatric hospitals for ten years at the opening of the novel. Whether he was like this when he entered psychiatric care, or became like this while in psychiatric care, remains ambiguous. Chief started pretending to be deaf and dumb as early as age ten, when he narrates a memory of three government visitors talking as if he were not present. By the start of Cuckoo's Nest, he is beaten down. I "used to be be big, but not no more," he says.

Chief's unusual physical size—6'7" or 6'8"—is a central metaphorical theme in the novel. By the end of the story, inspired by protagonist Randle McMurphy, the fog has cleared, and Chief feels "big" again. When he rips up the sink and smashes it through a window to break out, it's a neat physical manifestation of his new-found existential consciousness.

Watching McMurphy one day, the Chief realizes: " . . . maybe he truly is something extraordinary. He’s what he is, that’s it. Maybe that makes him strong enough, being what he is. The Combine hasn’t got to him in all these years; what makes the nurse think she’s gonna be able to do it in a few weeks? He’s not gonna let them twist him and manufacture him."

In the final scene of the novel, Chief is heading back toward his tribe's homeland along the Columbia River, proud again of who he is. He looks forward to going back, to see if anyone is still fishing on the dams, and to find out what's happened. When he ends his narration with "I been away a long time," it resonates literally and figuratively.

What was Chief Bromden's diagnosis for schizophrenia in One Flew Over the Cuckoo's Nest?

Although the Chief is a schizophrenic, he is the narrator of the story, so this presents an interesting challenge to the reader -- how reliable is he as a narrator?

The Chief was diagnosed as a "chronic" schizophrenic (split personality) supposedly as as a result of what he suffered during World War II. Chronic means that his illness is severe and ongoing, with little hope of improvement. He has been treated with shock treatment, which was considered a viable but barbaric last resort treatment for mental illness back in the day. In severe cases of depression, shock treatment is still used, only it is quite different than what was done to the Chief. Although the Chief has been diagnosed as a schizophrenic and has some paranoid delusions (The Combine), he is pretty clever. He pretends to be deaf and dumb. In this way, he can eavesdrop on conversations and find things out without people realizing it.