During the 1964 presidential election, a magazine called Fact ran a poll of psychiatrists on Barry Goldwater, the GOP nominee who was regarded by many as a right-wing kook and an unstable warmonger. The psychiatrists, none of whom had examined Goldwater, largely echoed that sentiment in their responses, and after Goldwater lost, he sued successfully for libel. As a result of the scandal, the American Psychiatric Association introduced the "Goldwater rule," which stated that psychiatrists should refrain from giving their professional opinion on public figures they have not treated. For decades, this was an uncontroversial policy that resulted in scant complaint from psychiatrists.

And then came Donald Trump. Upon his election, some of the foremost psychiatrists in the country began raising alarm bells in letters to (among others) then president Barack Obama, the New York Times, and New York City's Department of Health and Mental Hygiene warning about the paranoia, grandiosity, delusions, narcissism, and abusive, violent, and exploitative tendencies they saw in the country's incoming president.

This April, Bandy Lee, a professor in Yale's psychiatry department, organized a town hall meeting to discuss the Goldwater rule in the age of Trump. Two dozen leading psychiatrists attended, while many others declined to publicly affiliate themselves with the conference but tuned in online.

The argument for condemning Trump—which the attendees agreed with—is that diagnosis is different from an assessment of danger. It's not possible or appropriate to diagnose Trump from afar, but they believe that it's possible to assess his dangerousness. They base this on a 1976 California Supreme Court case, Tarasoff v. Regents of the University of California, in which the judges ruled therapists must warn a potential victim if a "patient presents a serious danger of violence to another." But Lee and those who agree with her are extending that obligation to warn the country about Trump even though he's not their patient.

Needless to say, this is controversial. The American Psychiatric Association vigorously disagreed with the premise, arguing that commentary on public figures by professionals violates the principle that consent and authorization must be given for a psychiatric evaluation to take place, and that public statements about Trump's mental health undermine the integrity of the profession. The Yale departments that initially supported the conference pulled out before it began, though they allowed Lee to hold it. (When I talked to Lee, she made sure to emphasize that she didn't speak for her university.)

But the idea that psychiatrists are publicly questioning the president's mental health obviously struck a nerve. After the conference, a bidding war to publish a collection of essays by the participants broke out between several top publishing houses. The resulting book, The Dangerous Case of Donald Trump (out October 3 from Thomas Dunne), was put together in three weeks.

I recently spoke to Lee, who edited the book, about her views, her disagreement with the American Psychiatric Association, and why she believes you should need to go through a mental health screening to be president.

VICE: The book talks about the distinction between Trump being "crazy like a fox" (saying what he does is for political purposes) and "crazy crazy" (grandiose, paranoid, and disconnected from reality.) Do you think a lot of people think the problem with assessing Trump's dangerousness is that he is "crazy like a fox"?

Bandy Lee: This is when having specialist knowledge helps. People who are "crazy crazy" often wish to present themselves as "crazy like a fox," or "not really crazy," but true illness follows distinct patterns of pathology that eventually give away people who are pretending. I work mainly in correctional settings, and very skillful individuals may deceive some clinicians for a while, but eventually the patterns either fit or do not. Mr. Trump's patterns of pathology have become so consistent and difficult to conceal that it is likely that he is highly impaired—although I refrain from giving a definitive opinion.

The Tarasoff case was about a doctor who had examined a patient. How can that Tarasoff doctrine be justifiably extrapolated to someone who hasn't been examined?

The Tarasoff doctrine is only a specific instance of "the duty to warn" and "the duty to protect" that is the foundation of our practice. The case gave rise to those phrases, certainly, but the duty to protect the health and well-being of patients or the public is a basic principle in all our ethical codes, be it the APA's, the AMA's, the Geneva Declaration, or the Hippocratic Oath.

We have mandatory reporting laws, physician's emergency certificates, and other legal allowances or requirements in addition to the Tarasoff rule. Tarasoff itself has expanded through hundreds of court cases over 40 years, while Goldwater is based on just one, more than a half century ago.

The book includes the suggestion that politicians should be required to submit to a mental health screening at some point in the nomination process. Would that prevent some of the risk you're talking about?

We are advocating that there be procedures in place to evaluate for fitness for duty every presidential candidate and every president, now and into the future, just like any other military officer or civilian serviceperson. It can be very dangerous when the commander in chief is not held to the same standard, and we are seeing those dangers play out now.

How would a fitness for duty test work as part of the democratic process? Who would administer it? Given that half of the population would be disappointed with either outcome, would it be possible for people to believe the administrators of the test were apolitical?

Congress would be in charge of making a legal provision for it. Once a commission is established, it could then be the legal structure for a separate and independent expert panel to offer recommendations to. We recommend that the panel members be nominated by the nonpartisan, nongovernmental National Academy of Medicine to remove conflicts of interest, and that experts serve six-year terms, with each member being rotated off and replaced each year. Once the examinations become annual and routine, there should be no question about bias against any party, and results should be kept strictly confidential unless there is a question about fitness for duty.

When would the test take place? If it took place after the election, or after the nomination, would the results of the election or nomination be invalidated? And what would happen if a president was found to be mentally unfit after having been elected? It seems like there would be a real chance a president-elect's supporters would riot.

The test would take place annually, for all serious candidates, preferably before nomination or election. It should become a requirement, just as it is with other military and civilian jobs. Administering it for the first time will be difficult, especially for a sitting president, and this is why it must be done sensitively and prudently.

Do you worry that raising questions about Trump's mental health could backfire politically? How would you answer critics who think questioning Trump's mental state make liberals look hysterical?

I don't doubt that there will be political backlash. Many mental health professionals have not spoken out for various reasons, but now that we have come to the brink of a devastating nuclear war if not a civil war, we ought to reflect on how our silence has enabled pathology to spread. Given our ordinary norms of practice—mandatory reporting, physician's emergency certificate at the slightest suspicion of danger, and the positive duty to warn and to protect—we are late, rather than hysterical.

We are not all liberals, but we are all professionals who routinely deal with risk assessment, regardless of ideological camp—and denial of real danger is a common trait that should heighten concern, not lessen it.

You told New York magazine around the time of the conference that you were a "pariah in (your) own department." Did you feel this way before the conference, or was it the conference that made you feel this way?

I may have said that word, but the article sensationalized it to the point of being inaccurate. The truth is, my colleagues almost universally agreed with me in secret, but none were willing to come forth. The university supports free speech, and the School of Medicine supported me to the end, allowing me use of its prime auditorium space. I was the one who "released" the school from sponsorship because of the general atmosphere of fear, and I didn't want to embroil my alma mater into a difficult situation. So I took it upon myself to be singled out, but no one forced me. The headlines the next day confirmed my suspicions of politicization: We were called "Democrats" who are "breaking the Goldwater rule" (neither was true) for political reasons, and I was glad I separated out my institution. Although it was still attacked, it could have been worse.

Why do you think the American Psychiatric Association has taken the stance that it has, doubling down on the Goldwater rule?

This is only my guess, but I would not be surprised if the APA was feeling what I experienced when I was organizing the ethics conference at Yale. Most psychiatrists were not staying silent because of the Goldwater rule, but because of the fear of being "targeted," either by a litigious president or his violence-prone followers.

The APA has made a drastic change in its position since this past presidential campaign, going against its previous interpretations of the Goldwater rule, which was becoming more lenient, turning it essentially into a gag order on any comment on public figures at all. I would not be surprised if it did this to allow cover for itself and the profession. It doesn't make sense otherwise that a rule that the APA even considered abolishing not too long ago should suddenly take precedence even over safety and survival. This goes against all other principles of medical practice and the Goldwater rule itself, which encourages educating the public about psychiatric issues related to public figures.

Whatever the reason, modifying an ethical rule in an intense political climate can be dangerous, as when the American Psychological Association modified its ethical rules to allow for torture during the Iraq War. So I cannot agree with the APA, and I know that it has been flooded with letters, protests, and resignations for doing this without consulting its membership. I am a firm believer in the Goldwater rule staying as it was before the modification. Exceptional times all the more require that we abide by the ordinary standards of our practice and not give up our principles.

Correction: An earlier version of this article incorrectly referred to the American Psychiatric Association as the American Psychological Association.