Dr Bandy X Lee, who has worked at the Yale School of Medicine and is a consultant for the World Health Organisation, was concerned about the lack of mental health checks for future US leaders.
The forensic psychiatrist stated that further wellbeing checks were desperately needed due to the tremendous strain a leader can be under.
She told Express.co.uk: “I still recommend that all presidential and vice-presidential candidates take fitness tests before assuming office.
“It is an incredible omission that a commander-in-chief is not required to take even the routine test that all military officers, law enforcement personnel, and even those performing mundane jobs such as toxic waste removal must take.
“Yet positions of power disproportionately attract individuals who are dangerously disordered.”
“The last is resignation and quitting.”
Dr Lee detailed her full conclusions about the US leader in her new book Profile of a Nation: Trump’s Mind, America’s Soul.
She was deeply fearful of President Trump being reelected – something she claimed could bring about mass public outrage.
Dr Lee said: “American democracy will surely be destroyed, the country will descend into violence and chaos.
“It would begin a very dark time for the nation as well as the world, since brutal dictators and fascist regimes will flourish everywhere.”
Dr Bandy X Lee’s work can be read online here.