title: Inflammatory mechanisms in major depressive disorder.
abstract: OBJECTIVE
  As the 'monoamine hypothesis of depression' fails to explain all aspects of major depression, additional causes are being investigated. Several observations suggest that inflammatory mechanisms pay a role in the cause of major depressive disorder (MDD). This article reviews their role in major depression.
  
  
  RESULTS
  Recent studies support the concept that inflammatory mechanisms play a crucial role in the pathomechanisms of major depression. Major depression shares similarities with 'sickness behavior', a normal response to inflammatory cytokines. Elevations in proinflammatory cytokines and other inflammation-related proteins in major depression were found in plasma and cerebrospinal fluid (CSF) as well as in postmortem studies. Elevated levels of proinflammatory cytokines persist after clinical symptoms of depression are in remission and can also predict the onset of a depressive episode. Antidepressant treatment can lead to a normalization of elevated cytokine levels in major depression. Finally, we understand how inflammatory mechanisms affect the metabolism of tryptophan and how nonsteroidal antiinflammatory drugs (NSAIDs) can interfere with the effects of antidepressants.
  
  
  CONCLUSIONS
  Further studies are needed to fully understand the role of inflammatory mechanisms in major depression and the potential treatment implications.
authors: Department of Psychiatry, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada. thomas.raedler@albertahealthservices.ca
authors: Thomas J
authors: TJ
authors: Raedler
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D000928:Antidepressive Agents / Q000627:therapeutic use; D016207:Cytokines / Q000378:metabolism*; D003865:Major Depressive Disorder / Q000188:drug therapy / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007249:Inflammation / Q000378:metabolism
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000928:Antidepressive Agents; D016207:Cytokines