The problem with Narcissistic Personality Disorder is....

[Tommy_Carcetti]

.....the people who have it are likely not ones to admit they have it (since it's not in their nature to admit personal weakness), and thus they don't seek out treatment for it.

So given that technically you can't diagnose someone with NPD without having personally examined them, and because people with NPD aren't seeking out treatment themselves, usually you are left merely speculating that someone showing all the telltale signs of NPD has NPD but you can't definitively say that they have it.

In all likelihood, Donald Trump will never admit he has NPD or seek out treatment for it, leaving us to only speculate on what appears to be quite obviously NPD.

It's a big of a paradox.

[Lucinda]

1. However you want to label Trump, he is clearly unfit for the job.

And this is maybe the one time where I am not looking sideways at the armchair diagnosticians.
The dude is dangerous.

[Zambero]

2. He's been characterized as "diagnostically ill"

On the basis of what he says and how he acts day in and day out. Psychiatrists, psychologists, and mental health experts do not necessarily need someone like Trump to lay back in their patient rooms sofas and spill the beans, in order to reach a conclusion as to his mental state.