Family Aggregation of Schizophrenia: Heredity or Folie a Deux: About Two Cases

Delusion is the predominant semiological entity in psychosis, which can, like many psychiatric or non-psychiatric pathologies, have a family character, assuming in the first place a genetic causal link, but authors have been able to individualize the transmission of delusion between subjects -who are not necessarily all psychotic- through promiscuity, and have called it "folie à deux". Folie à deux or shared psychotic disorder is a rare diagnosis that is subject to controversy concerning its phenomenology, its nosography, and its psychopathology, questioning the nature of delirium and its occurrence outside a psychotic structure as well as the question of the contagion of the symptom in psychiatry. We propose the semiological analysis of two intrafamilial cases of folie à deux, the first case in which the clinical particularity is the shared delusional symptoms without any other psychotic symptoms, and the second case is characterized by the shared delusional and non-delusional psychotic symptoms. From there, we underline the inadequacy of a purely descriptive approach and emphasize the possible link with other more frequent clinical situations with the common point of the transmission of psychic symptoms between two or more persons. Then, we propose a therapeutic reflection involving a non-pharmacological approach and a preventive strategy to avoid the contagion of the said delirium between biologically vulnerable subjects.