The extensive report has cited more than 45 Republican and Democratic lawmakers and staffers who shared their thoughts on the mental fitness of Mr Biden as he prepares to take on Donald Trump again in November.
The statements from various insiders paint a bleak picture of a President struggling to grasp basic details, becoming increasingly hard to understand, and showing signs of physical deterioration.
One source said of a meeting with Mr Biden: “You couldn’t be there and not feel uncomfortable.”
They said that the President took 10 minutes to greet around 20 people before a meeting on funding for Ukraine.
It was also claimed that Mr Biden let his colleagues do most of the talking.
Another incident involved Mr Biden mixing up the names of two Hispanic cabinet secretaries.
The Wall Street Journal also dissected a public gaffe whereby Mr Biden appeared to not understand his own policy while talking to Republican Speaker Mike Johnson.
The conversation was again about funding for Ukraine, and insiders say Mr Johnson accused the President of “helping Vladimir Putin” with a policy that stops future permits for shipping liquefied natural gas to many countries, including in Europe.
But Mr Biden thought this was only a study, not one of his policies.