Holden Caulfield, a paradoxical figure

Holden's mindset is marked by the dichotomy between adulthood and childhood.
He despises the superficiality of adulthood. Then again, he desires to be free of the shackles of adolescence.

He ultimately a very confused figure, dislocated from society, unable to bridge this chasm between childhood and adulthood.

Think about the 1950s society. Even today we find mental health problems can be stoically hidden and remain shunned and misunderstood.

After the war, many young men were coming back from war, thrown back into a world of uniform suburbia. Increasingly Americans were subscribing to a collectivist ethic, no longer a form of rugged individualism. No wonder so many men and women felt 'dislocated' in this mass corporate culture.

Prescriptions for tranquilisers were given out slapdash. There was a general ignorance towards mental health issues. Either they were ignored or treated like a physical illness.

The Catcher in the Rye is full of evidence that Holden is depressed.
'I thought I'd just go down down down'
'You can't imagine'... (Direct address to reader, increases sense of pathos)
'I was sort of disappearing' ... minimisation of language, playing down/masking his emotions, a form of self protection? Or a denial of how dire his mental state is?

His red hunting hat is a symbol for this paradox.

It indicates he needs protection. 'My hunting hat really gave me quite a bit protection, in a way'
HIS NEED FOR COMPANIONSHIP AND HELP

But in another way, it is a symbol of his self alienation. It advertises his uniqueness. His need for isolation.
He is self conscious of it... he takes off his hat 'as not to look suspicious' before going to his home.
It is significant that Phoebe gives him his hat back at the end of the novel. It is a reciprocal interaction. About the only one in the novel. He says that when people give him gifts they always end up 'making me sad'. In this instance of giving Holden feels happy. [I believe he is guilt ridden. He says his brother was very intelligent. He feels inferior to his brother. Perhaps he feel guilty that isn't 'good enough'.] But this interaction is, in a way, Phoebes indicting that its okay that he needs like form of protection. An approval.