Adam Crabtree is a psychotherapist in private practice, specializing in dissociative identity disorder and other dissociative disorders. He is on the faculty of the Centre for Training in Psychotherapy and director of the LingYu psychotherapy training program in Toronto.
He is author of Multiple Man: Explorations in Possession and Multiple Personality. He has published the only extensive modern bibliography of mesmerism and its offshoots: Animal Magnetism, Early Hypnotism and Psychical Research, from 1766-1920, an Annotated Bibliography.
His study of the origins of dynamic psychiatry and psychology is titled From Mesmer to Freud: Magnetic Sleep and the Roots of Psychological Healing. He is author of writings in the areas of the history of psychotherapy, hypnosis and psychical research, as well as papers on William James and Charles Sanders Peirce. He wrote Trance Zero: The Psychology of Maximum Experience and is a contributing author of Irreducible Mind: Toward A Psychology for the 21st Century. He has called for a reconsideration and redefinition of hypnosis as a species of trance and has just completed a book manuscript with that theme: Memoir of a Trance Therapist: A Biographical History of an Idea.