As for antidepressants, it is reported that increased monocyte phagocytosis in depressed patients was reversed upon successful antidepressant treatments.46 Also, levels of pro-inflammatory cytokines, such as IL-1 and IL-6, which are released mainly from monocytes and macrophages, returned to control levels over a 6-week period upon successful antidepressant treatment in major depression patients.49,50 Alternatively, in an in vitro study,35 antidepressants inhibited the stimulated production of IFN-, while increasing the production of IL-10, an anti-inflammatory cytokine, in whole blood of healthy volunteers. Moreover, a variety of antidepressants including imipramine, venlafaxine, and fluoxetine are recently reported to have a common negative immunoregulatory effect by suppressing the IFN-:IL-10 ratio.