Donald Trump keeps breaking all the rules. And leadership being what it is, that is making others break them too. Take the Goldwater Rule.

You've never heard of the Goldwater Rule? Well, back in 1964, when Trump was just 18, his predecessor as Republican presidential nominee was Senator Barry Goldwater.

Though he was a model of virtue and moderation alongside the campaign excesses of recent times, there were fears among the nation's psychiatrists that Goldwater was - how to put it politely? - a few cents short of the dollar. A magazine called Fact polled psychiatrists and enough of them concurred with that view to allow a headline suggesting he was mentally unfit for office.

Goldwater, somewhat Trumpian in his views of the media, sued, successfully, and the magazine closed in the process. But another consequence was that the American Psychiatric Association added the "Goldwater Rule" to Section 7 of its Principles Of Medical Ethics. It makes clear that it is unethical for psychiatrists to give their medical opinion about public figures unless they have treated them personally and have their permission to talk about their diagnosis. However, some of the nation's top psychiatrists are finding it impossible to sit idly by amid fears that their president may be seriously mentally ill.

Barry Goldwater was named the Republican presidential nominee in 1964, his mental health came under much media scrutiny © PA Photos

On the back of Trump's retweeting of hate messages and videos by Britain First (you keep thinking he can go no lower, then he finds a way), the latest to break the Goldwater Rule was Dr Lance Dodes, a former Harvard professor now with the Boston Psychoanalytic Society And Institute.

Trump, he argued, is "a psychopath... an enormous present danger... a very sick man... displaying symptoms of psychosis". On Trump's compulsive tweeting, Dodes said, "The simple explanation for it is that he's not in control of himself. This is what we mean when we say that somebody is becoming psychotic or is briefly psychotic... All of his delusional ideas come up when he is stressed in some way and then he loses track of reality because it doesn't fit what he needs to believe." He also said it was "an extremely dangerous thing" for a position of power to be held by someone who "appears so wantonly unconcerned about the welfare of others and willing to do anything to promote himself".

It's not as though we weren't warned: remember his very first official visit after his inauguration, to the HQ of the CIA? Smart move, I thought: he is going to build bridges after the rows with the intelligence community during the campaign. But no. He stood in front of the wall of stars commemorating CIA officers killed serving the US and created a huge storm about the media reports that there had been bigger crowds for Barack Obama's inauguration than his - which there had. At best, chronic narcissism; at worst, a personality disorder that would be pretty scary in anyone, but frankly terrifying when we are talking about the president of the United States. Which is why the shrinks are refusing to be silent, rule or no rule.

Read more: Could Donald Trump start a nuclear war?