There is a letter to the editor submitted to the New York Times that pushes back against the myriad claims made by psychiatrists that Donald Trump is mentally ill. Specifically, he has been accused of suffering from Narcissistic Personality Disorder.

The letter, by the way, was written by the guy who came up with the criteria for labeling that disorder.

Most amateur diagnosticians have mislabeled President Trump with the diagnosis of narcissistic personality disorder. I wrote the criteria that define this disorder, and Mr. Trump doesn’t meet them. He may be a world-class narcissist, but this doesn’t make him mentally ill, because he does not suffer from the distress and impairment required to diagnose mental disorder.

Mr. Trump causes severe distress rather than experiencing it and has been richly rewarded, rather than punished, for his grandiosity, self-absorption and lack of empathy. It is a stigmatizing insult to the mentally ill (who are mostly well behaved and well meaning) to be lumped with Mr. Trump (who is neither).

The last line – that what these amateur diagnosticians are doing is an insult to those with true mental illnesses – is the most important part here. There are people who legitimately try to function with these illnesses on a day-to-day basis. Using their struggle to explain Donald Trump does nothing but stigmatize them.

This next paragraph is arguably the most important written on the subject of Trump’s mental state:

Bad behavior is rarely a sign of mental illness, and the mentally ill behave badly only rarely. Psychiatric name-calling is a misguided way of countering Mr. Trump’s attack on democracy. He can, and should, be appropriately denounced for his ignorance, incompetence, impulsivity and pursuit of dictatorial powers.

There is no reason to just throw the term out there without actually examining the man and his life on a personal level. You can’t do the kind of analysis needed to diagnose based on speeches and television appearances. Trump isn’t acting like someone with a mental disorder. He’s acting like someone who is full of himself and drunk with power.

The professor, clearly not a Trump fan, can be argued with over lines like “Trump’s attack on democracy,” but he is absolutely correct in his assessment that Trump isn’t mentally ill.