By the 1950s it had around 1,000 patients and major research and experimentation in the treatment of chronic depression and schizophrenia was being carried out. In 1952, after visiting Sandoz in Switzerland and meeting Dr. Albert Hofmann, Dr. Ronald Sandison moved to Powick and began pioneering British work in the psychiatric use of LSD, developing a program he called "Psycholytic Therapy" (literally "mind loosening therapy") for treatment of illnesses such as severe depression and schizophrenia. An LSD treatment unit was established at the hospital in 1958 in which Dr. Sandison administered his therapy until he left the institution in 1964. Medical Superintendent Dr. Arthur Spencer continued the program until Sandoz abruptly withdrew supplies of the drug in 1966, due to the problems of illicit recreational use. Records indicate that 683 patients had been treated with LSD in 13,785 separate sessions before the program was discontinued. In 2002 the NHS agreed to pay £195,000, in an out of court settlement, to 43 former psychiatric patients who were treated with LSD between 1950 and 1970.