CRP and major depressive disorder: In another study, responders (at least a 25% reduction on HAM-D-17) to minocycline on depression was observed specifically within the subgroup of patients with baseline CRP > 3 mg/L and baseline IL-6 predicted treatment response [105], and a different study on minocycline in bipolar depression found that patients with elevated baseline IL-6 levels responded better to minocycline [106].