CCL2 and COVID-19: In a meta-analysis of studies conducted on major depressive disorder, which included data derived from 45 longitudinal studies and more than 1500 depressive patients, the results showed that antidepressants in general, and selective serotonin reuptake inhibitors (SSRIs) and serotonin–norepinephrine reuptake inhibitors (SNRIs) in particular, reduced the plasma levels of several proinflammatory cytokines, including IL-6, TNF-α, and CCL-2, which could be involved in the pathogenesis of the cytokine storm observed in severe COVID-19, as previously noted [56].