A case of folie à deux dissociative (dissociative hysteria) disorder in an 8 and 12 year-old sister and brother is presented. Illnesses of this type are very rare and there is little medical literature on this subject. Our patients, almost simultaneously, abruptly had complete loss of memory, disorientation, loss of awareness about who they were, and much anxiety, which lasted about 15 hours. Both patients were physically well and no abnormalities were found on physical examination, routines laboratory tests and EEG studies. Speculations about the emotional and interpersonal causes of this illness in these two patients are given.
folie à deux; dissociative disorder; hysteria
