"Truly dangerous." What you should do if you come across a 'Donald Trump' type of narcissist.

When describing the narcissism of Donald Trump, Dr John Gartner compares him to a malignant tumour.

Because Trump, like many politicians, is a narcissist, according to psychologists. But they also believe he is a malignant narcissist, and that is so much worse.

Dr Gartner is a US psychologist and one of the contributors to 2017 book The Dangerous Case of Donald Trump, which contains essays from 27 psychologists, psychiatrists, and mental health professionals on the “clear and present danger” that US President Donald Trump’s mental health poses to the “nation and individual well being”.

Listen to Mamamia’s daily news podcast The Quicky on Donald Trump and narcissism. Post continues after audio.

He is also the president of Duty To Warn, an association of mental health professionals who believe Trump is psychologically unfit for office.

Consequently, these professionals have deviated from the American Psychiatric Association’s Goldwater rule, which holds that it is unethical for psychiatrists to give professional opinions about public figures without examining them in person.

Speaking to Mamamia‘s daily news podcast The Quicky, Dr Gartner explained that the experts believe that in the case of Trump, their duty to warn – where they can break confidentially if there is a clear danger to a person – is greater than the Goldwater rule.

"We felt as mental health professionals knowing what we know about psychology, we had a duty to warn the general population that Donald Trump shows the severe, dangerous character pathology that really predicts that he would be dangerous, and in fact that has proven to be the case," he told host Clare Murphy.

To diagnose narcissistic personality disorder, patients must display at least five of nine characteristics:

1. Grandiosity with expectations of superior treatment by others.
2. Fixated on fantasies of power, success, intelligence, attractiveness, etc.
3. Self-perception of being unique, superior, and associated with high-status people and institutions.
4. Needing constant admiration from others.
5. Sense of entitlement to special treatment and to obedience from others.
6. Exploitative of others to achieve personal gain.
7. Unwilling to empathise with others' feelings, wishes, or needs.
8. Intensely jealous of others and the belief that others are equally jealous of them.
9. Pompous and arrogant demeanour.

Dr Gartner said all of these traits are observable behaviours, so it is possible to diagnose the disorder of a public figure.

But, he warned, Trump exhibits behaviour far worse than typical narcissism. He displays a rare form of Narcissistic Personality Disorder called malignant narcissism.

"[This] combines narcissism with paranoia - all of his crazy conspiracy theories, his projections of evil on the press and to minorities and anyone who disagrees with him, his constant sense that he's a victim - and antisocial personality disorder which is the personality disorder of criminals, people who lie and have no conscience, who violate and exploit the rights of others and have no remorse about it.

"And finally the fourth component is sadism, which as it sounds, is taking pleasure in harming, humiliating or degrading other people."

This combination makes for a grim diagnosis: "When you put these four traits together, you have the most dangerous type of leader that it's possible to have," Dr Gartner said.

"That's why there was such a duty to warn people. It's not just that he's narcissistic, we certainly have many narcissistic politicians, it's that he's truly dangerous.

Dr Gartner explained that the release of Special Counsel Robert Mueller’s report on Russian interference in the 2016 election, which did not find President Donald Trump committed a crime, may embolden the President even further.

What makes matters worse is that there is no way to treat malignant narcissism.

"The person who trained me is now the living world's expert on malignant narcissism and the way he trained us is: If you're able to diagnose so that a patient has all four of these components... You should essentially run away because they're untreatable.

"They'll only exert a destructive influence on your life as the psychotherapist. This is an untreatable disorder... There's not a lot to feel good about."