A hundred days is the traditional measure of a new presidency. But sufficient for this president is the biblical metaphor for infinite woe. Each day evokes the CAT scan of a disordered brain, encasing President Trump’s psyche in an endless hall of mirrors. And now his maladies are ours:

Grandiosity. Lies. Impulsiveness. Anger. Unreasoning defensiveness. Consuming self-involvement. Craving for admiration. Lack of empathy. An inability to distinguish reality from his own needs. So striking is his behavior that numerous mental health professionals publicly opined that Trump’s mental state “makes him incapable of serving safely as president.’’

Little wonder. According to The Washington Post, two-thirds of his factual assertions have been completely false. Transparently, the concept of objective fact threatens his sense of self. And so Trump pits lies against truth in a Darwinian struggle to reshape our communal reality.

Some of this is risible. Much is not: He claims that 3 million illegal immigrants voted. He demeans our intelligence agencies. He asserts that the media covers up terrorism. He claims that immigrants go unvetted. Little matter if he believes his own lies, or merely wants us to. Trump is transforming the presidency into a soundstage for mendacity and paranoia.

In reprisal for challenging his falsehoods, he casts the media as “the enemy of the American people.’’ But only the media can serve as the purveyor of his lies and validator of his primacy. In the confused and needy tangle of his narcissism, they are the indispensable opponent and enabler. Never has honorable journalism been more essential — or more fraught with challenge and complexity.

This dilemma is captured by Trump’s attack on leaks. Only through anonymous sources do we know about his disturbing connection to Russia: its intrusions on Trump’s behalf in the 2016 campaign; the contacts between his campaign and Russian intelligence; Michael Flynn’s lies about his conversations with the Russian ambassador; or Trump’s concealment of Flynn’s misstatements. The more reality threatens Trump, the more he must obliterate it.

For Trump cannot accept our institutions as separate from himself. Take the courts. First he vilified Judge Gonzalo Curiel for his decision in a fraud case related to Trump University; then James Robart, the “so-called judge’’ who enjoined his seven-country Muslim ban; then the “disgraceful’’ Court of Appeals that upheld him. “If anything happens,’’ Trump announced, “blame him and the court system.’’ Thereby does respect for law erode.

This contempt for larger consequence is pervasive. Does his Muslim ban abandon our friends, strengthen our enemies, and endanger our intelligence personnel? No matter. Is climate change an existential threat? Not to Trump. Are we ignoring our moral obligation to refugees displaced by our policies in the Middle East? We have none. A solipsistic soul perceives no one but itself.

Thus Trump’s White House is a Hobbesian state of nature — warring factions terrified of their abusive leader. The apparatchik Reince Priebus appears powerless to check the novice Jared Kushner, the self-promoting Kellyanne Conway, the rabid Stephen Miller, or the obsequious Mike Pence. At whatever cost, Trump relishes minions fighting for his favor.

The man with no loyalty attracts none, spawning the leaks he deplores. Only the Russophile Steve Bannon thrives in his role as Rasputin to the czar, spreading dissension as he grasps for power beyond his abilities by advancing an ethno-nationalist mysticism that estranges our allies. The chaos spreads to all Trump touches.

To curb his pathology is imperative. For example, we must unearth the truth about Trump and Russia. Was he party to Russia’s efforts to influence our election? Why were campaign officials in touch with Russian intelligence? What are his financial ties to Russia, and why has he withheld his tax returns? Why did Trump hide Flynn’s lies from Pence and Priebus? Is his affinity for Putin psychological — or based on something even more disturbing?

Excepting Senators McCain and Graham, congressional Republicans seem less concerned with investigating these questions than with stifling the leaks that exposed them. In return for helping suppress the truth, they want Trump to sign off on their agenda: gutting Obamacare, entitlements, financial regulation, and consumer protection, while enacting tax cuts for the wealthy — contradicting much of what he promised his blue-collar base. Thus do myopia and narcissism collude.

Often at great cost. A disturbed and amoral leader, history has shown, can sicken a country whose institutions falter. Trump will not save America from himself. Nor will his party or, by themselves, the Democrats. That burden falls on the news media, the courts — and every citizen who cares.

Richard North Patterson’s column appears regularly in the Globe. His latest book is “Fever Swamp.’’ Follow him on Twitter @RicPatterson.