BACKGROUND: Psychology and psychiatry have long been influenced by the phenomena their practitioners study. A variety of ideas about the mind and its pathology were developed in the context of studies of hysteria, double and multiple personality and hypnotic phenomena. OBJECTIVES: In this study we argue that mediumship influenced both psychology and psychiatry in different ways. The study of mediumistic phenomena such as trances and written or verbal messages claimed to come from deceased spirits contributed to the development of several important concepts during the nineteenth century and later on. METHODS: We have reviewed the historical psychiatric and psychological literature relating to mediumship to identify discussions about mediumship. RESULTS: Mediumship was used to defend a variety of ideas about the subconscious mind by figures such as William B. Carpenter, Frederic W.H. Myers, and Joseph Grasset. Both Pierre Janet and Théodore Flournoy used mediumship to illustrate forms of dissociation. Similarly, psychopathology was related in different ways to the practice of mediumship, as discussed by Jean-Martin Charcot, Pierre Janet and Gilbert Ballet. CONCLUSIONS: While mediumship was just only one factor affecting concepts of the subconscious, dissociation and psychopathology, its influence needs to be more recognized than it is currently done in the historiography of psychology and psychiatry.
Mediumship; psychiatry; psychology; spiritism; psychical research; psychopathology
