Cao B, et al. - In the current systematic review and meta-analysis, adults with major depressive disorder (MDD) and healthy controls (HC) were compared regarding adipokine levels (i.e., leptin and and adiponectin levels). The possible role of adipokine regulation in the development and progression of MDD was also discussed. Findings suggested MDD be associated with lower adiponectin levels. In addition, males expressing lower adiponectin and leptin levels were at higher risk for developing MDD.