Influence of fluvoxamine on plasma interleukin-6 or clinical improvement in patients with major depressive disorder

OBJECTIVES The etiology of depression remains unknown. There is, however, a growing body of evidence that cytokines are involved in the pathophysiology of depression. The aim of this study is to investigate the effects of fluvoxamine on plasma interleukin-6 (IL-6) levels and on clinical improvement of the depressive state. SUBJECTS AND METHODS Thirty patients who met the DSM-IV criteria for major depressive disorder (MDD) were enrolled in the study. Thirteen were male and 17 were female, and their ages ranged from 26 to 70 years (mean ± standard deviation 45.0±14.2). The patients were treated with fluvoxamine for 8 weeks. The dosages of fluvoxamine varied among the patients and, based on ethical considerations, were not fixed. RESULTS The fluvoxamine doses were positively related to plasma fluvoxamine levels (r =0.8798, P<0.001). A significant correlation was observed between the patients' plasma IL-6 levels and their 17-item Hamilton Rating Scale for Depression (HAMD17) scores (r =0.4555, P=0.0010). A positive correlation was found between the delta plasma IL-6 (week 0-week 8) and the delta HAMD17 (week 0-week 8) (r =0.5226, P=0.002). CONCLUSION Effect of fluvoxamine on IL-6 is partially associated with its clinical efficacy for MDD.