For those who are concerned about the appropriateness of using psychiatric diagnostic tools to assess the mental fitness and dangerousness of President Trump the following:
It apparently is totally legitimate, even legally required, for mental health professionals to warn targeted people and society at large for the dangers a troubled person or group of persons might exhibit in their words, actions and plans. Such a warning is not a psychiatric diagnosis and therefore does not break the APA’s Goldwater Rule  against professionals making a distant diagnosis of a public figure. A very important footnote to the introduction of the recently published anthology “The Dangerous Case of Donald Trump”  reads as follows:
“Assessing dangerousness requires a different standard from diagnosing so as to formulate a course of treatment. Dangerousness is about the situation, not the individual; it is more about the effects and the degree of impairment than on the specific cause of illness and it does not require a full examination but takes into account whatever information is available. Also, it requires that the qualified professional err on the side of safety, and it may entail breaking other, ordinarily binding rules to favor urgent action.” 
The legal duty to warn others was initially encoded in an influential court case and is known as the Tarasoff Doctrine.  The plaintiffs in the case were the parents of a murdered female student who found out that the murderer, who was a fellow student and her ex-boyfriend, had confessed to his therapist that he intended to kill her. The parents sued the university for having failed to warn her of the possible danger she might have been in. “The court ruled that when a therapist determines, or should have determined, that a patient presents a serious danger of violence to another, the therapist has a “duty to protect” that other person.” 
Though some mental health professionals have deliberately decided to break the Goldwater Rule and make very precise statements about Trump’s mental health, many others abide by the rule but still feel compelled by the Tasaroff Doctrine to sound the alarm loud and clearly and warn the world that Trump is truly a danger to minorities, domestic peace and and is too close to the nuclear button, which he might push when cornered by his critics, political opponents or the legal system.
For the sake of the civilizational process and project and for the sake of the good fight against authoritarian conservatism bordering on an American variation of fascism, mental health professionals and other academics will have to share their insights with the public, and not merely to inform them but more importantly to increase the pressure on the political system to take care of this problem by either impeachment, invoking Article 25 or outright institutionalization. Their insights might also lead to diminishing the amount of people strangely mesmerized by the self-aggrandizing serial liar now occupying the White House. .
. A. The Goldwater Rule. B. “On Trump: Diagnosing 301.81 and the Goldwater Rule“. Alpheus. 21 Feb 2017.
. Lee, Bandy, M.D. (Ed.). 2017. “The Dangerous Case of Donald Trump: 27 Psychiatrists and Mental Health Experts Assess a President“. New York: St. Martin’s Press.
. Lee, Bandy. 2017. “Introduction” to “The Dangerous Case of Donald Trump”, p. 14.
. Simone, Simone & Fulero, Solomon M., PhD, JD. 2005. “Tarasoff and the Duty to Protect”. Journal of Aggression, Maltreatment & Trauma. Vol. 11, Iss. 1-2.