Story highlights Trump is responding to claims made in a new book by author Michael Wolff

CNN has not independently confirmed all of Wolff's assertions

Washington (CNN) President Donald Trump slammed reports questioning his mental stability in a series of tweets Saturday morning, writing he's a "very stable genius" after the publication of an exposé about his first year as President put the White House into damage-control mode.

"Now that Russian collusion, after one year of intense study, has proven to be a total hoax on the American public, the Democrats and their lapdogs, the Fake News Mainstream Media, are taking out the old Ronald Reagan playbook and screaming mental stability and intelligence ... " Trump wrote, referring to questions raised about the mental fitness of the former President, who disclosed in 1994 that he had Alzheimer's disease.

Now that Russian collusion, after one year of intense study, has proven to be a total hoax on the American public, the Democrats and their lapdogs, the Fake News Mainstream Media, are taking out the old Ronald Reagan playbook and screaming mental stability and intelligence..... — Donald J. Trump (@realDonaldTrump) January 6, 2018

"Actually, throughout my life, my two greatest assets have been mental stability and being, like, really smart," the President continued. "Crooked Hillary Clinton also played these cards very hard and, as everyone knows, went down in flames. I went from VERY successful businessman, to top T.V. Star ... to President of the United States (on my first try). I think that would qualify as not smart, but genius ... and a very stable genius at that!"

....Actually, throughout my life, my two greatest assets have been mental stability and being, like, really smart. Crooked Hillary Clinton also played these cards very hard and, as everyone knows, went down in flames. I went from VERY successful businessman, to top T.V. Star..... — Donald J. Trump (@realDonaldTrump) January 6, 2018

....to President of the United States (on my first try). I think that would qualify as not smart, but genius....and a very stable genius at that! — Donald J. Trump (@realDonaldTrump) January 6, 2018

After his tweets Saturday morning, Trump told reporters at Camp David that Wolff is a "fraud" who doesn't know him.

"I went to the best colleges, or college," he told reporters. "I had a situation where I was a very excellent student, came out and made billions and billions of dollars, became one of the top business people, went to television and for 10 years was a tremendous success, as you probably have heard, ran for President one time and won. Then I hear this guy that doesn't know me at all, by the way, didn't interview me, said he interviewed me for three hours in the White House. Didn't exist, it's in his imagination."

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