About 1 in 20 people report ongoing difficulties after their psychedelic experience, Dr. Charles Raison, a professor of psychiatry and human ecology at the University of Wisconsin School of Medicine and Public Health in Madison, told CNN in a prior interview. He was not involved in the new research.
“A year later, they say, ‘I had an experience that was so distressing to me that it messed up my ability to function, or alienated me from my family, or gave me post-traumatic stress disorder,’” Raison said.