The mental health professionals who were alarmed by candidate Donald Trump’s psychological instability had to deal with the distraction of something the general public had long forgotten about, the Goldwater rule which you may have read about in my Daily Kos stories and elsewhere including this article in Psychology Today where I am mentioned.
The eminent psychiatrist Robert Jay Lifton said in an interview with Bill Moyers:
I think the Goldwater Rule is a little ambiguous. We adhere to that portion of the Goldwater Rule that says we don’t see ourselves as making a definitive diagnosis in a formal way and we don’t believe that should be done, except by hands-on interviewing and studying of a person. But we take issue with the idea that therefore we can say nothing about Trump or any other public figure. We have a perfect right to offer our opinion, and that’s where “duty to warn” comes in. We have a duty to warn on an individual basis if we are treating someone who may be dangerous to herself or to others — a duty to warn people who are in danger from that person. We feel it’s our duty to warn the country about the danger of this president. If we think we have learned something about Donald Trump and his psychology that is dangerous to the country, yes, we have an obligation to say so. That’s why Judith Herman and I wrote our letter to The New York Times. We argue that Trump’s difficult relationship to reality and his inability to respond in an evenhanded way to a crisis renders him unfit to be president, and we asked our elected representative to take steps to remove him from the presidency.
Trump seems to want his own version of the Goldwater rule, not to apply mental health professionals, rather to apply to retired members of the intelligence community.
This is the American Psychiatric Association’s rule informally dubbed as the Goldwater rule.
Section 7, which appeared in the first edition of the APA's Principles of Medical Ethics in 1973 and is still in effect as of 2018, says:
On occasion psychiatrists are asked for an opinion about an individual who is in the light of public attention or who has disclosed information about himself/herself through public media. In such circumstances, a psychiatrist may share with the public his or her expertise about psychiatric issues in general. However, it is unethical for a psychiatrist to offer a professional opinion unless he or she has conducted an examination and has been granted proper authorization for such a statement.
The following is the Trump version. If he gets away with it it may come to be called the Brennan Rule.
On occasion, those hold who a security clearance may decide to express an opinion about the president's fitness for office or use that information to investigate the president. This is forbidden and considered treason punishable by life in prison or the death penalty.