New-onset psychosis in children represents a complex presenting symptom. Psychosis can be attributable to a combination of factors and etiologies, and all possible causes must be systematically examined. There is growing evidence that a proportion of psychosis/psychiatric manifestations in children may be immune-mediated, and physicians should consider this etiology in each presentation of first-episode psychosis. Immune-mediated encephalopathies/encephalitis are increasingly being recognized in children with antibodies to N-methyl-D-aspartate receptor, Leucine-rich glioma-inactivated 1 or other central nervous system antigens such as Contactin-associated protein-like 2, glutamic acid decarboxylase, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid or Gamma-aminobutyric acid B. In this study, we describe 3 cases of immune-mediated encephalopathy/encephalitis with prominent psychiatric symptoms at presentation, and suggest a practical diagnostic and treatment approach for children with acute psychosis of an immune-mediated cause. Read more…