"Morning Joe" host Joe Scarborough said people on President Trump's campaign had told him and host Mika Brzezinski they had feared Trump's mental health was starting to decline and he was in pre-dementia.

Brzezinski reported on how Trump had posted a video of Speaker Nancy Pelosi, D-Calif., showing her stumbling over her words during her press conference on Thursday. "Wonder what that’s about," she asked.

"Well, we know what it’s actually about," Scarborough said. "The president, of course, during the campaign, we’ve said it, people closest to him told us that they feared that he was in mental decline. People very close to him told us that he feared he was pre-dementia, that he had changed.

"You watch Donald Trump in the late 1980s, you watch him even in the 90s, you watch him now, he is completely changed," he said.

[Also read: George Conway escalates attack on Trump's mental state]

The hosts defended Pelosi, insisting she is "tougher today" and "sharp as a tack."

"The difference between Nancy and Donald, not even close. He knows he’s slipping and so now they’re — it’s incredible, they’re doctoring videos," Scarborough said.

Tensions between Trump and Pelosi has risen after a meeting at the White House — which was supposed to be about infrastructure — was cut short by Trump, objecting to Pelosi saying she believes he "is engaged in a cover-up."