Communicated insanity, folie a deux and shared psychotic disorder - Different concepts and a case in Mallorca

Following an earlier description of the psychopathological conceptions of " communicated insanity" we focus on a remarkable difference concerning the d evelopment of the historical terminology. The current operationalized defin ition is oriented at the originally French conception of the "folie a deux" which includes an adoption of certain delusional ideas by an intimate othe r. Compared with that, in the German psychopathological tradition those cas es were also included in the conception of the "induziertes Irresein", in w hich the shocking experience of another's psychosis may cause a psychotic i llness of somebody else. In modern psychiatric terminology this kind of "in duction" is rather disregarded. We report a case of an induced psychosis in two women and give particular attention to the German psychopathological t radition because of still existing clinical relevance.