title: The role of microbes and autoimmunity in the pathogenesis of neuropsychiatric illness.
abstract: OBJECTIVE
  To illustrate how microbes might participate in the pathogenesis of neuropsychiatric illness by triggering the production of autoantibodies that bind to brain targets.
  
  
  RESULTS
  Some studies link exposure to infectious agents to development of brain disorders; others have identified autoantibodies in individuals with these conditions without finding evidence of pathogens. Neither line of work demonstrates consistent associations between a specific neuropsychiatric disease and a particular environmental trigger or immune marker. Growing evidence suggests that the microbiome conditions host immunity to microbes and xenobiotics, and regulates autoimmune responses that can affect the central nervous system (CNS). The presence of CNS receptors for cytokines and other immune molecules underscores the importance of brain-immune crosstalk in maintaining normal function. An increased prevalence of familial autoimmunity, exposure to pathogens prenatally and postnatally, and findings of antibrain antibodies is common in disorders as diverse as schizophrenia, obsessive-compulsive disorder and autism, and suggests that differences in exposure timing and genetic vulnerability toward autoimmunity are important determinants of neuropsychiatric outcomes.
  
  
  CONCLUSIONS
  Microbes, both pathogenic and commensal, can induce autoantibodies that bind to brain and affect behavior in susceptible hosts. Interventions that correct the microbial balance or diminish autoantibody binding may be effective in diverse neuropsychiatric conditions mediated by autoimmunity.
authors: Department of Epidemiology, Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, New York 10032, USA. mady.hornig@columbia.edu
authors: Mady
authors: M
authors: Hornig
mesh_terms: D001323:Autoantibodies / Q000096:biosynthesis; D001327:Autoimmune Diseases / Q000382:microbiology / Q000523:psychology*; D001812:Blood-Brain Barrier / Q000276:immunology; D003141:Communicable Diseases / Q000276:immunology / Q000523:psychology*; D006801:Humans; D001523:Mental Disorders / Q000276:immunology / Q000382:microbiology*; D064307:Microbiota; D018716:Molecular Mimicry / Q000276:immunology
chemical_list: D001323:Autoantibodies