it's not uncommon for people to make glib judgments about the mental health of others, because we think that we understand what disorders entail. when i was working in offices, i noticed a lot of this: an immature and garrulous employee being labeled and partially excused because others were certain he had adhd, or a moody and indecisive boss dismissed as bipolar. [as you can imagine, that one struck me as particularly ignorant and, since i was the audience, ironic.] but in the case of trump, even professionals are weighing in on the subject. no fewer than twenty-seven psychiatrists have collaborated on a book called the dangerous case of donald trump. up to now, it's been understood that medical professionals don't comment on the cases of people they haven't evaluated themselves, for obvious reasons. when psychiatrists appear in the media to talk about someone's mental health, it's generally to explain what a condition is, what the warning signs are, or how it's treated, and most will be quick to point out that they are not going to address questions of a particular person's mental state.
the book's authors are very conscious of the fact that they are placing their footprints on a professional moon here, but their rationale is that there comes a point where the warning signs are so abundant that it would be more irresponsible to remain silent. one doctor has even said that the president's mental state is an imminent threat to the nation.
one can also argue that the interdiction against indirect diagnosis is one that doesn't necessarily apply to the modern world, or at least that it doesn't apply to the example of someone like donald trump. after all, no one has done more to cause concern over trump's mental health than the man himself, whether it's his desperate tweets about how smart, successful and well-loved he is, or his tendency to drift aimlessly from one idea to another within the course of a single sentence. social media and the non-stop news cycle has already given us more insight into the minds of public figures than we've ever had, but trump pushes that much further; he completely rejects any idea that he should present a front that is in any way presidential, gracious, or polished. furthermore, he is incapable of remaining silent on any subject, so that we are constantly drowning in a river of sewage gushing forth from his addled brain.
the two most common diagnoses given by observers are that trump suffers from narcissistic personality disorder, or that he shows signs of dementia. he does fall, broadly speaking, into the risk group for both: narcissistic personality disorder is diagnosed more frequently in men than women by a 3 to 1 margin, while his age increases his risk of dementia the same as it does for everyone. that, combined with his bizarre and very public behavior, is enough for many to ring alarms.
these two fallback explanations for trump are very different things: some level of dementia affects between 5 and 8 percent of people over 60 worldwide, making it pretty common. although it's far more common among poorer people, it isn't something that's unknown in the white house: reagan showed marked deterioration in his second term and did indeed develop alzheimer's. [the extent of reagan's deterioration in office is still hotly debated.] the condition is degenerative and will absolutely affect trump's ability to do his job. it's something that disqualifies him from being president because there is no predicting how far or how fast it will progress, only that it will do so.
a personality disorder is something more ephemeral. it's hard to predict what will happen, how it can be treated and how it will affect the person with it. the nature of personality disorders in general isn't well understood, and it's compounded by the fact that some of them seem "gendered", being applied far more often to either men or women, depending on the exact criteria. trump's ridiculous self-aggrandizement, his seeming inability to feel empathy and his willingness to justify anything in his past do seem like the hallmarks of a narcissist. and some have been able to make a compelling case that his statements do form a roadmap of the npd checklist.
i'm not anywhere near qualified to question psychiatrists' evaluations of trump, since they're more versed than i'll ever be. but i do have an uneasy feeling about the public desire to explain trump's "eccentricities" by saying they're caused by a mental disorder. it's not just that i get uncomfortable with the idea of non-professionals [which most of the opinion-givers are] making calls based on incomplete or flawed information. what worries me more is that, by trying to explain trump's behaviour, we're actually excusing it.
dementia doesn't explain why trump and his father were brought up on charges for refusing to sell their properties to blacks. it doesn't explain why the man who makes such a show of adoring the military refused to serve in it. it doesn't explain why he was able to stick to a very consistent claim that president obama wasn't born in the united states.
likewise, it's easy to confuse someone who has narcissistic personality disorder with someone who is a narcissist. not every narcissist has a disorder. and, for what it's worth, one of the people involved in establishing the clinical definitions of personality disorders says that trump doesn't meet the criteria. first and foremost, his point is that suffering from a mental disorder involves... suffering. trump, on the other hand, pursues his narcissist's agenda in order to get personal rewards. people with mental disorders have a compulsion to act the way that they do. acting badly because it can generate gains is a matter of forethought.
the other danger is that we start to equate mental illness with being unable to perform jobs like that of president: ones with great power and responsibility. but even if donald trump does suffer from narcissistic personality disorder, he'd hardly be the only president to have spent time in office fighting demons. it's well-established that abraham lincoln suffered from major depression for years. no one is saying that he was unfit for the job.
if trump is unfit, it is not because he has a mental disorder, but because he is incompetent on every requirement necessary for the job.