Distinguishing Reality: A Case of Delusional Misidentification Syndrome in a 39-Year-Old Male.

Capgras syndrome (CS) is a type of delusional misidentification syndrome where an individual is under the impression that a person they know has been switched with an identical imposter. One theory for the development of CS is a disturbance among the frontal, limbic, and temporal areas, which creates an alteration in an individual's ability to recognize a person's face and provoke a response emotionally. The primary risk factors for the development of CS include having a neurological disorder and a diagnosis of schizophrenia. We present a case of a 39-year-old male with a past medical history of traumatic brain injury and familial history of schizophrenia who presented to the Emergency Department with paranoia and the belief that his father had been switched with an imposter. After ruling out organic causes, he was stabilized on olanzapine before discharge to outpatient follow-up. This case highlights the importance of prompt recognition of the symptomatology associated with CS and treatment with olanzapine for a favorable outcome.