IL1B and major depressive disorder: Rats that were subjected to chronic mild stress (CMS) for 12 weeks showed obvious depression and anxiety‐like behaviors; in addition, the activation of microglia in the hippocampus was detected, NLRP3 was also activated, and the expressions of IL‐1β, IL‐6, and other inflammatory mediators were upregulated, suggesting that neuroinflammation induced by microglia activation may play an important role in the pathogenesis of CMS‐induced depression‐like behavior.37