The role of tumor necrosis factor-alpha and other cytokines in depression: what dermatologists should know.

Recent studies have suggested that inflammatory responses may play an important role in the pathophysiology of depression. In fact, depressed individuals have been found to have higher levels of pro-inflammatory cytokines, especially tumor necrosis factor-alpha (TNF-α) and interleukin-6. This appears to be independent of any pre-existing chronic inflammatory disorders. In this article, various studies correlating increased levels of cytokines to depression are reviewed. As much as 60% of individuals with psoriasis also suffer from clinical depression. TNF-α antagonists, frequently used in the treatment of psoriasis, may be helpful in directly reducing depressive symptoms for patients with psoriasis and other chronic inflammatory conditions.