He was a part-time professor, until 2015, for 28 years at Johns Hopkins University Medical School,[3] and is a widely published author of books, and of articles for scientific and other journals.
[3] According to Gartner, Trump's mental handicaps are a mixture of narcissism, paranoia, sociopathy and a measure of sadism.
[10][11] In an attempt to raise public awareness about Trump's apparent cognitive challenges and the extreme danger they represent to the nation if he were to take back the White House in the 2024 United States presidential election, Gartner started a petition at Change.org called "We diagnose Trump with probable dementia: A petition for licensed professionals only".
[12] John Gartner, Harry Segal, and their expert guests, weekly Podcast sessions analyze the psyche of Donald Trump, "documenting his cognitive decline and (...) his malignant narcissism" e.g. at Spotify.
[13][better source needed] Gartner is the author of numerous scholarly articles and several books, including: