AUTHOR=Hainmueller Thomas , Lewis Lambert , Furer Tzvi TITLE=Case report: Anti N-methyl-D-aspartate autoimmune encephalitis following a mildly symptomatic COVID-19 infection in an adolescent male JOURNAL=Frontiers in Psychiatry VOLUME=Volume 14 - 2023 YEAR=2023 URL=https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2023.1270572 DOI=10.3389/fpsyt.2023.1270572 ISSN=1664-0640 ABSTRACT=Background: Antibodies against N-Methyl-D-Aspartate receptors are the most commonly identified cause of autoimmune encephalitis. While predominantly associated with malignancies, cases of anti-N-Methyl-D-Aspartate receptor autoimmune encephalitis have been described after infections with herpes-simplex virus or recently in patients with severe Covid-19 disease.A previously healthy male 17-year-old adolescent acutely developed psychosis with auditory and visual hallucinations, fluctuating mental status, and an isolated seizure five weeks after a mildly symptomatic Covid-19 infection. Symptoms continued to worsen, and catatonia and additional neurological symptoms developed during initial antipsychotic treatment. Diagnostic workup revealed antibodies against N-Methyl-D-Aspartate receptors in the cerebrospinal fluid without other major abnormalities. After establishing the diagnosis, initiation of immunomodulatory therapy stopped symptom progression and led to full recovery within 2 months.The case is remarkable in that Anti-N-Methyl-D-Aspartate receptor autoimmune encephalitis developed shortly after Covid-19 infection in an adolescent despite only having mild Covid symptoms. The diagnosis should be considered in cases of acute-onset psychotic symptoms during or after Covid-19 infection, particularly in individuals without prior psychiatric history who present with atypical psychiatric or neurological features.