You are already dead: Case report of nihilistic delusions regarding others as one representation of Cotard's syndrome.

Background: While the symptom of "I am already dead" is a hallmark of Cotard's syndrome, also known as nihilistic delusions, the symptom of "you are already dead" has been neglected. Case presentation: A woman aged in her 60s diagnosed with schizophrenia was admitted to our hospital for psychotic symptoms, including delusions of reference, delusions of guilt, auditory hallucinations, cenesthetic hallucinations, agitation, depression, suicidal ideation, and catatonia. During hospitalization, her cenesthetic hallucinations progressed to include nihilistic delusions. She described cenesthetic hallucinations along with various delusional descriptions, including the belief that various objects, such as spoons, irons, nails, rulers, bins, and coins, were inside her body and that her body was being burned or in danger of exploding. She also claimed an altered sense of her own body, that her body was larger than normal or reversed. Moreover, she reported nihilistic delusions that her face and body did not exist, that her heart was not functioning, and that she was going to die soon or was already dead. She occasionally refused to eat because of the feeling of being dead. Notably, during a severe episode, she claimed that a doctor in front of her was dead. Clozapine was effective in improving her symptoms. Ultimately, the patient regained her sense of being alive and acknowledged that the doctor was alive. Conclusion: We report the case of a patient presenting with nihilistic delusions regarding both self and others, along with prior cenesthetic hallucinations. Aberrant interoceptive processing could be a potential link between these two forms of nihilistic delusions.