Nature Reviews Neuroscience 9, 46-56 (January 2008) | doi:10.1038/nrn2297

From inflammation to sickness and depression: when the immune system subjugates the brain

Robert Dantzer1,2, Jason C. O'Connor1, Gregory G. Freund1,2, Rodney W. Johnson1 & Keith W. Kelley1,2  About the authors


In response to a peripheral infection, innate immune cells produce pro-inflammatory cytokines that act on the brain to cause sickness behaviour. When activation of the peripheral immune system continues unabated, such as during systemic infections, cancer or autoimmune diseases, the ensuing immune signalling to the brain can lead to an exacerbation of sickness and the development of symptoms of depression in vulnerable individuals. These phenomena might account for the increased prevalence of clinical depression in physically ill people. Inflammation is therefore an important biological event that might increase the risk of major depressive episodes, much like the more traditional psychosocial factors.

Author affiliations

  1. Integrative Immunology & Behavior, Department of Animal Sciences, College of Agricultural, Consumer and Environmental Sciences, University of Illinois, Urbana-Champaign, Illinois 61801, USA.
  2. Department of Pathology, College of Medicine, University of Illinois, Urbana-Champaign, Illinois 61801, USA.

Correspondence to: Robert Dantzer1,2 Email: