A typical case report exemplifies existing links between paraphrenia and affective disorders. Kraepelin noted similarities between paraphrenia and manic-depressive illness, particularly between mania and paraphrenia confabulans. Thereafter, the German school has insisted on similarities of symptoms and course of the two entities. The French school, on the contrary, has insisted on the instrumental role of affective disorder in the development of paraphrenia: paraphrenia is considered as a potential evolution of primary psychotic disorders. If cases of post-schizophrenic paraphrenia have been reported, the development of paraphrenia on a background of bipolar disorder seems rarer. Such a case is presented and discussed, supporting the concept and its mechanisms as illustrated by French psychiatrists.