BDNF and schizophrenia: An exaggerated IRS response is counterbalanced by the activation of the CIRS system (anti-inflammatory cytokines production) and neurotrophic defenses (including antioxidants and brain-derived neurotrophic factor (BDNF) production), but this is relatively inadequate to inhibit IRS activation; therefore, impairments in the CIRS response are correlated with the severity of schizophrenia symptoms and poor clinical outcomes in TRS [4,14,24].