He was one of the founders of modern hypnotherapy and his work notably found use in psychological warfare during the Cold War.
As part of his work for the CIA, he developed techniques of what he called "hypno-conditioning."
[citation needed] In 1969, the California State Board of Medical Examiners found Bryan guilty of “unprofessional conduct in four cases involving sexual molesting of female patients”, and he was given five years' probation.
[2] William Turner and Jonn Christian hypothesized in The Assassination of Robert F. Kennedy that Bryan was responsible for inducing Sirhan Sirhan to fire blanks at Robert F. Kennedy with posthypnotic suggestion.
[3] Bryan was reportedly found dead in a Las Vegas hotel room on March 4, 1977, of a suspected heart attack, and buried in Hollywood.