CXCL8 and major depressive disorder: Higher baseline proinflammatory cytokine (IL-6 and IL-8) levels and poorer antidepressant responses have been found in BD.[16] However, other findings indicate that improvement in symptoms of depression and anxiety after treatment is not associated with changes in inflammatory markers.[17] Elevated levels of the acute phase reactant C-reactive protein (CRP) are a very sensitive marker of acute inflammatory reactions.