Daniel Harold Casriel (March 1, 1924 – June 7, 1983) was an American psychiatrist, psychoanalyst and writer from New York City. Dan Casriel's method of group psychotherapy continued. His novel road map to happiness evolved into a framework for the field of relationship education as the relationship roadmap for couples. Dr. Casriel also founded the Daytop treatment centers, which were strongly inspired by the psychotherapy cult Synanon.