During his time in the Trump administration as chief of staff, John Kelly purchased a book written by a former Yale psychiatrist in an effort to understand his boss’ “psychoses.” That’s according to a new book out next week called The Divider, written by The New York Times’ Peter Baker and The New Yorker’s Susan Glasser, a copy of which The Daily Beast has obtained. “Among those who secretly bought a copy of the psychiatrists’ book was none other than John Kelly, who sought help to understand the president’s particular psychoses and consulted it while he was running the White House, which he was known to refer to as ‘Crazytown,’” the duo writes. The book Kelly reportedly bought was written by now-fired Yale psychiatrist Bandy Lee and called The Dangerous Case of Donald Trump, which explored Trump’s alleged mental stability. Kelly further said to others that Trump’s “inflated ego was in fact the sign of a deeply insecure person,” Baker and Glasser write. The Daily Beast couldn’t reach Kelly for comment on Thursday evening.