Plasma levels of adiponectin and tumor necrosis factor-alpha in patients with remitted major depression receiving long-term maintenance antidepressant therapy

Adiponectin, an adipose tissue-specific plasma protein, is involved in insulin sensitization and has anti-atherosclerotic properties, whereas tumor necrosis factor-α (TNF-α), a pro-inflammatory protein, plays important roles in inflammatory endothelial injury and atherosclerotic changes. It has been reported that adiponectin and TNF-α inhibit each other's expression and production in adipocytes. Several in vitro studies indicated that antidepressant medications decreased the production of pro-inflammatory cytokines including TNF-α, but the effect of antidepressants on the expression of adiponectin is still unknown. We examined the plasma levels of TNF-α and adiponectin in patients with remitted depression receiving maintenance antidepressant therapy for longer than half a year, and compared the levels with those in healthy controls. The plasma levels of TNF-α and adiponectin in the remitted depression group were significantly lower and higher than those in the control group, respectively. This preliminary cross-sectional study suggests the possibility that maintenance antidepressant therapy may have anti-inflammatory effects and prevent the development of atherosclerosis.