However, works aimed to study how the host system changes in these types of psychiatric disorders are still lacking. A study involving a relatively small cohort of MDD patients and healthy volunteers reported that NLRP3 mRNA and protein levels are increased in peripheral blood mononuclear cells in MDD patients, as caspase-1 and IL-1β, and normalized to healthy levels upon antidepressant treatment (245). This evidence concerns the gene IL1B and major depressive disorder.