Paul Ryan spoke to a doctor and extensively researched how to deal with someone with narcissistic personality disorder after Trump won: book

• Paul Ryan studied up on how to deal with someone with narcissistic personality disorder after Trump won the 2016 election.
• According to a new book, Ryan also spoke with a New York doctor about it and read about it "for weeks."
• Ryan, then the House Speaker, was reportedly caught off guard when Trump defeated Clinton.

Then-House Speaker Paul Ryan started studying how to interact with people with narcissistic personality disorder after Donald Trump won the 2016 election, according to a new book by The Washington Post's Bob Woodward and Robert Costa.

Insider obtained an early copy of "Peril," which is set to be released next week.

According to the book, Ryan was caught off guard when Trump won the election in an enormous upset over Democratic nominee Hillary Clinton. Republicans controlled the House and Senate, and Ryan, realizing that he would have to work with Trump, started researching how to deal with someone who is "amoral and transactional," the book says.

A wealthy doctor in New York, who was also a Republican donor, contacted Ryan later and told him, "You need to understand what narcissistic personality disorder is," according to the book.

"What?" Ryan asked, at which point the doctor sent the Wisconsin Republican an email detailing his "thoughts on how to best deal with a person with anti-social personality disorder," Woodward and Costa reported. The email also included links to articles about the topic in The New England Journal of Medicine, and information from the International Statistical Classification of Diseases and Related Health Problems, 10th edition.

The book said that "Ryan studied them for weeks, convinced Trump had the personality disorder."

Trump and Ryan's relationship was fraught with tension throughout the latter's tenure as speaker of the House. Among other things, Ryan butted heads with Trump after he publicly defended the neo-Nazis who sparked a deadly riot in Charlottesville, Virginia in 2017.

"We must be clear," Ryan tweeted after the riot. "White supremacy is repulsive. This bigotry is counter to all this country stands for. There can be no moral ambiguity."

According to "Peril," Trump called Ryan afterward and blew up at him over the statement, shouting, "You're not in the foxhole with me!"

"Are you finished?" Ryan reportedly yelled back. "May I have some time to speak now? You're the president of the United States. You have a moral leadership obligation to get this right and not declare there is a moral equivalency here."

But Trump refused to back down, saying, "These people love me. These are my people. I can't backstab the people who support me," according to the book.

When Ryan pointed out that there were white supremacists and neo-Nazis in the crowd, Trump conceded, "Well, yeah, there's some bad people. I get that. I'm not for that. I'm against all that. But there's some of those people who are for me. Some of them are good people."

The two men also found themselves at odds in early 2018 after Congress sent a $1.3 trillion omnibus package to Trump for his signature. The president wanted to veto the bill and, according to the book, shouted at Ryan during a White House meeting that "this is a terrible deal!"

"Who signed off on this piece of shit?" Trump asked, the book said. "This is a piece of shit, a bad fucking deal."

Ryan eventually got Trump to sign the bill by dispatching then Defense Secretary James Mattis to the Oval Office, saying, "If you're standing there, he'll do it."