Anti-NMDA Receptor Encephalitis in a Female with Previous Psychiatric Illness

In 2007, a rare form of autoimmune encephalitis was characterized by Dalmau et al. termed as anti-N-methyl-D-aspartate (anti-NMDA) receptor encephalitis. Although it is more common in young females with ovarian teratomas who often present with psychiatric symptoms for the first time, this case reports a female diagnosed with antiNMDA receptor encephalitis in the absence of a neoplasm and diagnosis of major depressive disorder and possibly bipolar disorder many years before the diagnosis of encephalitis. This case further presents multiple relapses of encephalitis, possibly due to absence of neoplasm and lack of treatment in first episode, since these factors have been reported to contribute to an increase in relapse risk rate. It is important to include antiNMDAR encephalitis in the differential diagnosis of psychiatric illnesses such as schizophrenia and major depressive disorder as anti-NMDAR encephalitis is treated with immunotherapy and tumor removal (if applicable) and the role of psychotropic medications is not clear.