Capgras Syndrome with Delusion of Negation

The coexistence of Capgras syndrome and Cotard’s syndrome is exceptionally rare, particularly in individuals without identifiable stressors or comorbid psychiatric conditions. Capgras syndrome involves the delusional belief that familiar persons have been replaced by impostors, whereas Cotard’s syndrome is characterized by nihilistic delusions, including beliefs of being dead or decaying. We present a case of a 28-year-old female with an 8-month history of symptoms consistent with both syndromes, despite having a low Positive and Negative Syndrome Scale score (<30) and no evidence of schizophrenia, mood disorders, or other psychiatric illnesses. The absence of precipitating factors makes this presentation diagnostically challenging and clinically significant. This case emphasizes the importance of recognizing isolated delusional syndromes and maintaining a broad differential diagnosis, as early identification and intervention are crucial even when typical psychiatric comorbidities are absent.