Objective: We present a case of anti-N-methyl D-aspartate (NMDA) receptor encephalitis that illustrates the dilemma that psychiatrists face in evaluating patients with first episode psychosis.
Conclusions: The discovery that acute psychosis can be the presenting feature of autoimmune encephalitis (in particular encephalitis caused by anti-NMDA receptor antibodies) has both practical and theoretical consequences. First, this condition is an important, but often overlooked, differential diagnosis of first episode psychosis.