A Brief History of Immunological Research into Psychosis and Pathways for Immune Influence of the Brain

Abstract

Infection and inflammation resulting from a malfunctioning of the immune system have been discussed as pathological factors in psychosis for more than 130 years. The first immune-modulating therapeutic approaches for psychosis were developed more than 100 years ago, but the breakthrough of antipsychotic treatment in the 1950s shifted the emphasis of research to catecholaminergic neurotransmission. In the 1990s, however, the unsatisfactory therapeutic effects of antipsychotics, and the fact that the pathological mechanisms of psychosis were still unknown, reignited the scientific interest in other topics, including inflammation. In parallel, the further development of immunological methods enabled a more sophisticated examination of immunological and inflammatory mechanisms. Psychiatrists' interest in this interdisciplinary field increased as a consequence of encouraging results of psychoneuroimmunological research and broader funding of the field. In the meantime, the benefits of anti-inflammatory treatment in psychosis have been demonstrated in clinical studies and meta-analyses. Future studies are warranted to evaluate the exact immunological mechanisms in the pathophysiology of the disease, optimize the anti-inflammatory treatment approach and develop more targeted, personalized therapies in psychosis.