Mr Conway is a conservative activist and a fouding member of The Lincoln Project, and has been one of the most vocal Republican critics of the one-term president, despite his wife’s job in the Trump administration.
Mr Trump put out a statement through spokesperson, Liz Harrington, in response to a tweet with a picture of Mr Conway from a CNN appearance, asking if the lawyer was “OK?”
“No, he’s mentally ill, a very sick man. I don’t know what Kellyanne did to him, but it must have been really bad. She has totally destroyed this guy—his mind is completely shot!” said Mr Trump.
It is not the first time that Mr Trump has taken a shot at Mr Conway.
In 2019, while still in office, Mr Trump took to Twitter to brand him a “total loser” the day after Mr Conway publicly questioned the then-president’s mental health.
In turn, Mr Conway mocked Mr Trump for ensuring that “millions of more people are going to learn about narcissistic personality disorder.”
Last month, Mr Conway said that he hoped that Vladimir Putin’s successor would release whatever files the Russian government may have on Mr Trump.
“I wonder someday, that maybe we’ll have a president in Russia who actually acts in the best interest of the Russian people and behaves himself before the world… maybe we’ll see the files on Donald Trump,” Mr Conway told CNN.
“I think those would be interesting.”
Ms Conway, the first woman to successfully manage a presidential campaign when she worked for Trump in 201, left the White House in August 202, and said she was doing so in the best interests of her four children.