of, relating to, involving, or inducing psychotic alteration of behavior and personality
About the word:
This word from psychotic + mimetic (meaning "imitative") first appeared in 1956, as mind-altering drugs began catching on with the public.
The word's unpleasant association with psychosis inspired Dr. Humphry Osmond to coin the synonymous psychedelic. That shifted the emphasis to examining how the agent might help enlarge the vision or explore the mind.