Psychotic States brings together a number of the author's papers written between 1946 and 1964 dealing with the psychopathology and treatment of various psychotic and borderline conditions from a psychoanalytic viewpoint. Taking the theories and techniques developed by Melanie Klein in her work with infants and young children, the author investigated their application to a range of psychotic syndromes, including chronic and acute schizophrenia, severe hypochondriasis, drug addiction, severe depression and manic depression, both to determine their possible therapeutic efficacy and to see what light they might shed on the etiology of the psychosis.