Inflammatory markers as predictive factors for selective serotonin reuptake inhibitors (SSRI) antidepressant effect
ntroduction: Data have supported the influence of inflammation in the pathophysiology of depression and also the influence of depression in the development of a pro-inflammatory state. Major depressive disorder (MDD), the core depressive condition, has selective serotonin reuptake inhibitors (SSRI) as its first line pharmacological treatment. Efforts have been made to identify predictive factors for the responsiveness to SSRI. Therefore, we conducted this review to evaluate the hypothesis that baseline levels of inflammatory markers predict the responsiveness of MDD to SSRI treatment. Methods: A search in the PubMed database was made including the keywords (“SSRI” or “sertraline” or “citalopram” or “fluvoxamine” or “escitalopram” or “fluoxetine” or “paroxetine”) and (“cytokines” or “CRP” or “TNF” or “inflammatory”) and (“major depressive disorder” or “major depression”). Results: The search retrieved 245 manuscripts, from which 12 fulfilled our inclusion criteria. The analysis of these manuscripts suggested that high levels of interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α) and c-reactive protein (CRP) at baseline might predict low responsiveness of MDD to SSRI treatment. Confounders such as cognitive impairment, chronicity and severity of depression, melancholic subtype, age and gender were not systematically included in the studies. Conclusion: Findings of this review suggest that high levels of pro-inflammatory markers at baseline might predict low responsiveness of MDD to SSRI treatment. Studies with adequate control for confounders are needed.