Andrew Feldmar is a psychotherapist who has been in the private practice of psychotherapy for over 44 years, in Vancouver, Canada. He was inspired to practice a form of radical (from radix, root) therapy, by R. D. Laing, who was his teacher, therapist, supervisor and later friend and colleague. He was introduced to research with and the therapeutic use of psychedelics in 1967. His interest in entheogen-assisted therapy has never flagged. He has published many books in Hungarian. He lectures, teaches, provides supervision and therapy internationally.