As the above post noted, Holden Caulfield often appears to be at odds with other characters and incapable of making correct judgments about his own behavior in Catcher in the Rye. He makes many observations about the behavior of others, particularly with respect to how “phony” almost everybody is, but, as is true in real life, he does not necessarily look at himself as critically.
The author, J.D. Salinger, doesn’t fully disclose Holden’s condition until the very end of the story. Readers can tell that he appears to be unraveling to some extent as he leaves Pencey and makes his way home. But it is not until the final chapter that we find out that he has actually been hospitalized. While he doesn’t say a whole lot about his time in treatment, he does tell us something important:
A lot of people, especially this one psychoanalyst guy they have here, keeps asking me if I’m going to apply myself when I go back to school next September. It’s such a stupid question, in my opinion. I mean how do you know what you’re going to do till you do it? I think I am, but how do I know? I swear it’s a stupid question.
We can see from this statement that Holden is still not able to analyze his own mind very well. This calls into question his reliability as a narrator because we have to wonder how accurate his statements are when he cannot make relatively simple judgments about himself, much less others.
Finally, in the book’s last paragraph, Holden says:
About all I know is, I sort of miss everybody I told about.
The fact that he has, at least to some extent, changed his mind about people who affected him so negatively casts doubt on his original judgments about them. We have to consider the likelihood that his feelings toward these characters were strongly influenced by his own state of mind, which we now have reason to question.
Holden is definitely a character who is presented as being out of control of his emotions at particular stages of the novel. Of course, on the one hand he is very open about this, telling the reader about how he broke the car window with his hand after his brother's death, but at other points the reader is only able to spot that Holden is not being truthful with himself by the reactions of others. A classic example of this comes in Chapter 17 when Holden meets up with Sally and they go iceskating. When Holden makes his somewhat idyllic proposal for them to elope and live in the woods together, he clearly begins to shout and raise his voice. As they are in a public place, Sally asks him to lower his voice. Note how Holden responds:
"Stop screaming at me, please," she said. Which was crap, because I wasn't even screaming at her.
Holden, when he gets into one of his rages, clearly loses the ability to see his own actions and understand how they might be impacting others. This is just one of the examples that show him to be an unreliable narrator.