There are several very distinctive examples of his behavior throughout the novel.
First of all, Holden seems to have a serious problem accepting his problem and does not use the appropriate words to describe his condition. He may imply that he has PTSD, but does not admit it at any time in the novel. The following quote displays how Holden uses the word 'hate',for what he is experiencing instead of referring to his condition as 'fear'. "I mean I' ve left schools and places I didn't even know I was leaving them. I hate that...but when I leave a place I like to know I'm leaving it." (p.4) The fact that Holden does not seem to know when he will leave a place, can be quite alarming, because it is human curiosity to have the need to be accepted by a group and understand why you are asked to leave. His ignorance makes the reader believe that he is able to handle things alone.
Another example which displays Holden's disorder would be when he returns to his dorm covered in blood, trips over his roommate's shoe and nearly falls down. It is obvious that he has no patience and gets angry easily. "What the hellya doing, anyway?" (p.46); however, the strangest thing of all is when Holden asks his roommate to play a card game "Ya wanna play a little Canasta or don'tcha? (p.47) as if nothing has just happened between him and Stradlater. He cannot recognize the seriousness of various events and does his best to avoid them. Strangely enough though, soon after he expresses his loneliness "Boy, did I feel rotten. I felt so damn lonesome." (p.48). These sudden mood changes give the reader the impression that he is unstable and is never satisfied.
Furthermore, when Holden is sitting on a bench and starts reading a magazine, it is clear that whatever he reads affects him, making him believe that he is suffering from lousy hormones or even cancer. "So I started getting worried about my hormones. Then I read this other article about how you can tell if you have cancer or not." He does not give himself the chance to filter what he is reading, on the contrary, he simply takes the information in and begins to experience extreme concern. Once again he handles life with negativity and feels that he is doomed.
A final example which helps show just how depressed Holden is the way he dealt with his brother's death.
"I was only thirteen, and they were going to have me psychoanalyzed and all, because I broke all the windows in the garage. I don't blame them. I really don't. I slept in the garage the night he died, and I broke all the goddam windows with my fist, just for the hell of it." (p.38-39) He misses his brother very much, basically because he found refuge in the fact that even though Allie was younger, Holden knew he could depend on him being there for him. Everyone seemed to believe that Allie was an amazing student and person, something that did not threaten Holden, on the contrary, he admired his younger brother as if he were older. So when he lost him, Holden's world caved in and becomes obsessed with
death.
All in all, the protagonist of the novel is struggling with PTSD but does not want to admit it. He pretends that everything is alright the one minute and then loses control the other. He should grow up mentally and come to realize that bad things happen to everyone and negativity is not the proper way to deal with them. Holden is not only struggling with PTSD, he is struggling with life.