President Trump. (Justin Lane/European Pressphoto Agency)

Maybe I’m doing this all wrong.

For five years, I’ve been identifying Donald Trump, now president of the United States, as a nutter. I’ve called him crazy, daft, a madman, barking mad and mad as a March hare, and I’ve “diagnosed” him — I’m not a mental-health professional and have never examined the president — with narcissistic personality disorder and more. To that list, I feel compelled to add a few more technical observations: He also seems off his rocker, ’round the bend and a few fries short of a Happy Meal.

The belief that the commander in chief is barmy has become commonplace. Just this week two prominent senators, Jack Reed (D-R.I.) and Susan Collins (R-Maine), were caught on a hot mic discussing Trump.

“I think he’s crazy,” Reed said. “I mean, I don’t say that lightly and as a kind of a goofy guy.”

“I’m worried,” Collins replied.

(Senate Appropriations Committee)

Now I’m worried, too. If the president really is — gulp — insane in the clinical sense and not just in the goofy sense, then perhaps we shouldn’t be ridiculing him. Maybe I, and other critics, should approach him calmly, speak in hushed tones and treat him with compassion.

For advice, I turned to the recognized authority on such matters, the Internet. It turns out that, when it comes to best practices for dealing with serious mental disorders, I’m doing a lot of the “don’ts” with Trump but not the things I should be doing.

Don’t use sarcasm. Avoid humor. Don’t criticize, accuse or blame. Avoid sounding patronizing or condescending. Don’t assume they are not smart. Be respectful. Be aware that the delusions they may experience are their reality. Stay calm. Minimize distractions. Turn off the TV. Simplify — one topic at a time. Stick to present issues. Acknowledge what the other person says and how they feel, even if you don’t agree.

All good advice, no doubt. Certainly, our patient would benefit from turning off the TV and minimizing distractions. He does much better when issues are simplified. He reacts poorly to criticism and accusation. And, unnervingly, he seems to believe the many false things he says.

But what works with troubled friends or family members doesn’t work quite so well when dealing with world’s most powerful man. You can’t just smile reassuringly when he tells you millions of people voted illegally in the election but he has no evidence that Russia interfered.

Both Reed and Collins have, quite rationally, softened their hot-mic conversation about Trump’s irrationality. A Collins spokeswoman said that the senator’s worry about Trump was a reference referring to his handling of the budget. Reed, in an interview, told me he thinks Trump’s troubles are more the result of inexperience than any neuropathology.

We’re seeing “somebody who has operated basically his whole life without anybody to check him,” with no concept of the “highly structured governmental sphere with checks and balances and legal restraints in terms of who does what,” Reed said.

Trump, he said, has a “moment-to-moment” way of thinking, without an orderly, long-term strategy. When it comes to strategic thinking, “it’s difficult to discern who’s doing that,” said Reed, an Army veteran and top Democrat on the Armed Services Committee, who — incredibly — Trump has not once consulted.

Reed said he was encouraged that Trump has delegated, somewhat more than previous presidents, to figures such as Jim Mattis at the Pentagon and the commanders. He also sees growing willingness in Congress to defy the president on matters ranging from Russia sanctions to the budget.

That is encouraging, but it’s insufficient. Consider the list of irrational actions coming from the White House over the past week alone:

●Trump’s new communications director alleged that the president’s top strategist attempts an anatomically improbable sex act to himself, called White House Chief of Staff Reince Priebus a paranoid schizophrenic and accused him of a felony. Priebus, one of Trump’s only tethers to mainstream Republicans, quits.

●Trump attacked Republican senators such as Lisa Murkowski (R-Alaska) whose votes he needed but failed to get on the GOP health-care bill, dealing it yet another defeat.

●Trump publicly attacked his own attorney general and threatened to fire his health and human services secretary.

●The Boy Scouts had to apologize after Trump gave a hyper-partisan speech to children.

●Trump caught the Pentagon by surprise when he announced he’s kicking transgender people out of the military, after botching the facts on Hezbollah while meeting the Lebanese prime minister.

And he jokes about being chiseled into Mount Rushmore.

It all brings to mind one more piece of advice I found online for dealing with people with serious mental-health issues: It may be necessary to lower your expectations.

Twitter: @Milbank

Read more from Dana Milbank’s archive, follow him on Twitter or subscribe to his updates on Facebook.