TLR4 and schizophrenia: In addition to the TRIPS (Toll-like receptors in immuno-inflammatory pathogenesis) theory [161], which proposes that schizophrenia risk is associated with neurodegeneration mediated by TLR3 and TLR4 activation, we hypothesise (Figure 1) that stressful events during the neurodevelopmental stage, either due to MIA, childhood trauma, or other insult, results in increased ROS (reactive oxygen species) followed by damage to the cells in the brain, which in turn produces DAMPs and cytokines that are recognised by TLRs on microglia, causing microglial activation.