Inflammation and immunity in schizophrenia: implications for pathophysiology and treatment.

Complex interactions between the immune system and the brain might have important aetiological and therapeutic implications for neuropsychiatric brain disorders. A possible association between schizophrenia and the immune system was postulated over a century ago, and is supported by epidemiological and genetic studies pointing to links with infection and inflammation. Contrary to the traditional view that the brain is an immunologically privileged site shielded behind the blood-brain barrier, studies in the past 20 years have noted complex interactions between the immune system, systemic inflammation, and the brain, which can lead to changes in mood, cognition, and behaviour. In this Review, we describe some of the important areas of research regarding innate and adaptive immune response in schizophrenia and related psychotic disorders that, we think, will be of interest to psychiatric clinicians and researchers. We discuss potential mechanisms and therapeutic implications of these findings, including studies of anti-inflammatory drugs in schizophrenia, describe areas for development, and offer testable hypotheses for future investigations.The work was supported by a doctoral clinical research training fellowship grant from the Wellcome Trust to Golam Khandaker (094790/Z/10/Z; 2010-‘13), grants from the Stanley Medical Research Institute and the National Institutes of Mental Health (grant# MH-94268) to Robert Yolken, and grants from the Wellcome Trust (095844/Z/11/Z & 088869/Z/09/Z), and the NIHR (RP-PG-0606-1335) to Peter Jones.This is the accepted manuscript. The final version is available from Elsevier at http://www.thelancet.com/journals/lanpsy/article/PIIS2215-0366%2814%2900122-9/abstrac