IL6 and mental disorder: The so called “sickness behaviour” induced by pro-inflammatory cytokines such as interleukin-1 (IL-1), interleukin-6 (IL-6) and tumour necrosis factor alpha (TNFα) includes symptoms such as malaise, fatigue, anorexia, cognitive problems and pain (Dantzer, 2009), which, if sustained, align with symptoms of mental disorders.