Just a month away from seating at the highest position in the United States, president-elect Donald Trump faces another dire criticism as three psychiatry professors from leading Universities in the country express their grave concern over the mental stability of the next head of state.

In the letter written for the outgoing president Barack Obama, Psychiatry Professor Judith Herman, M.D. from Harvard medical School expresses her fear that the next president is not mentally fit to assume his elected post. The letter was written by Herman and two other distinguished psychiatry professors: Nanette Gartrell, M.D. and Dee Mosbacher, M.D., Ph.D., both previously taught at University of California, San Francisco.

"We are writing to express our grave concern regarding the mental stability of our President-Elect," the professors wrote in the letter published in the Huffington Post. "His widely reported symptoms of mental instability lead us to question his fitness for the immense responsibilities of the office."

The symptoms of mental stability referred in the letter include "grandiosity, impulsivity, hypersensitivity to slights or criticism and an apparent inability to distinguish between fantasy and reality".

This is not the first time that the Trump was questioned for his mental stability. Numerous mental health professionals claim that Trump satisfied the Diagnostic and Statistical Manual (DSM) Criteria for Narcissistic Personality Disorder. Psychologist Kevin Dutton from Oxford University showed that Trump has more psychopathic traits than Nazi dictator Adolf Hitler based the Psychopathic Personality Inventory - Revised (PPI-R), according to NDTV.

Due to these alarming possibilities of mental instability, many psychiatrist in the U.S. including Herman and company, strongly recommend a full medical and neuropsychiatric evaluation by an impartial team of investigators before Trump assume office.

Psychiatrist fears that a president with Narcissistic Personality Disorder could attack another nation and trigger another world war even for little reasons, including a Tweet or a news report of a foreign leader criticizing or mocking him.