The finding that influential pro-inflammatory cytokines IL-6, TNF-α, or IFN-γ were associated with symptoms of depression (self-depreciation and hopelessness) and suspiciousness, but not to hallucinations, delusions, or negative symptoms, is also consistent with finding that inflammatory markers were associated with depressive symptoms in schizophrenia [12, 20]. Here, IL6 is linked to major depressive disorder.