Lysergic acid diethylamide (LSD) has been used at Powick Hospital since 1952. During the early years of the treatment it became apparent that many of the dramatic psychic manifestations of the drug, including the vivid hallucinatory experiences, sensory hyperacuity, etc., were of no therapeutic value and that the chief use of the drug lay in its ability to bring into consciousness repressed traumatic experiences and relationships suffered by the patient during childhood. In particular, feelings such as those of parental rejection and hostility, sexual assaults, the sense of loneliness and impending doom engendered by inhalant anaesthetics in a strange hospital environment were repeatedly recovered and abreacted with great release of emotion. LSD appeared to be unique in the ease with which under its influence these deeply repressed memories could be recovered, and analysts using the drug in relatively small doses found that it would produce in one or two sessions unconscious material which would normally only be recovered after some months of analysis.