Posted with permission from Newsweek

The ghostwriter of President Donald Trump’s bestselling book The Art of the Deal has suggested that the president may suffer from a personality disorder and said he is “deeply disturbed and utterly untrustworthy.”

Tony Schwartz, who spent 18 months shadowing the businessman in the 1980s, offered his opinion on Trump’s fitness for office ahead of the publication of a collection of essays by 27 psychiatrists and mental health experts assessing the president’s psychological condition.

“The question that this book raises in a number of its essays by psychiatrists is: Is Trump crazy like a fox or is he just crazy?” said Schwartz, appearing on CNN’s Anderson Cooper 360 on Thursday.

“And I think the overwhelming weight of evidence suggests that he’s just crazy, and not crazy, casual crazy. I’m talking about crazy—I’m not a psychiatrist so I actually can get away with saying this—but crazy as a personality disorder.”

Read more: Donald Trump will resign soon to save face, "The Art of the Deal" co-author predicted

The authors of the collection of essays—entitled The Dangerous Case of Donald Trump —concluded that Trump is “the most dangerous man in the world,” and that his role and behavior as president of the United States poses a threat to the safety and wellbeing of American citizens.

Schwartz also said that White House Chief of Staff John Kelly was man-managing Trump in a bid to limit the negative impact the president’s actions could have.

“I do believe John Kelly knows clearly that Trump is deeply disturbed and that he is utterly untrustworthy and he is managing him all the time out of some belief—put aside ideology—out of some belief that it’s better that he be there than he not be there,” said Schwartz.

“I never met anybody who worked for Trump who didn’t know who Trump was within a very short time.”

The question of Trump’s mental fitness has arisen on multiple occasions during the presidential campaign and his first eight months in office. Psychiatrists are generally prohibited from commenting on the mental health of public figures without examining them under the Goldwater rule.

The principle was introduced by the American Psychiatric Association (APA)—the biggest psychiatric group in the U.S. and the world—after a 1964 survey of psychiatrists in U.S. magazine Fact concluded that Republican presidential candidate Barry Goldwater was unfit for the office. Goldwater lost the 1964 election to Lyndon Johnson.

But there have been numerous examples of psychiatrists and mental health professionals bucking the rule after claiming they felt they had a duty to warn the public of the purported danger posed by Trump. In February, a letter signed by 35 mental health professionals and sent to the New York Times said that the “grave emotional instability indicated by Trump’s speech and actions makes him incapable of serving safely as president.”