Concept-based therapeutic communities emerged out of the informal group meetings of Charles Dederich and a number of former Alcoholics Anonymous members in California in the late 1950s. The model was exported worldwide and has not only become the most widely used approach to residential treatment but has proved enormously influential in the development of many other treatment approaches; both residential and ambulatory. Concept-based therapeutic communities are hierarchical, and the staff and residents form a chain of command. Staff are often qualified for their work by virtue of having been...