NLRP3 and depressive disorder: In this study we (1) present an overview of the literature on peripheral (i.e., human peripheral blood mononuclear cells (PBMC)) activation of the NLRP3 inflammasome in mood disorders; (2) demonstrate the development and validation of an appropriate technical approach using two concurrent detection methods: immunofluorescence and protein levels to study the activation of the NLRP3 system in PBMC; (3) apply this assay in a pilot clinical sample set of adolescent patients with mood disorders, i.e., bipolar disorder (BD) or depressive disorder (DD).