Unmasking the Neuropsychiatric Veil: A Mortality Case of Delayed Diagnosis in Anti-NMDAR Encephalitis Presenting as Acute Psychosis

Acute psychosis, a prominent manifestation of Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, poses a diagnostic challenge as it closely mimics primary psychiatric disorders. Consequently, clinicians may inadvertently initiate antipsychotic treatment, inadvertently exacerbating the underlying pathology. We presented a mortality case of late detection of anti-NMDAR encephalitis in a young man who presented with acute psychosis which developed further deterioration after initiated anti-psychotics. This underscores the inherent risk in misdiagnosing anti-NMDAR encephalitis when acute psychosis is the primary clinical presentation. The delay in recognizing the neurological underpinnings of the symptoms resulted in a detrimental progression of the disease in the young male subject. This illuminates the critical need for heightened clinical suspicion when confronted with acute psychosis, prompting clinicians to consider alternative diagnoses beyond conventional psychiatric conditions. In conclusion, this article contributes to the ongoing discourse on the challenges associated with diagnosing anti-NMDAR encephalitis, particularly when masked by psychiatric symptomatology. It underscores the imperative for clinicians to maintain a high index of suspicion, prompting comprehensive evaluations to avert delayed diagnoses and potential fatalities in cases of this severe neurological condition. Keywords: Anti-NMDAR encephalitis, acute psychosis, antipsychotic, delirium.