Sixty-one unmedicated adults — 75% female, mean age of 45 years — with major depressive disorder, body mass index > 25 kg/m2, and plasma high-sensitivity C-reactive protein (hs-CRP) ≥ 3.0 mg/L were randomly assigned to receive EPA 1 g/d, 2 g/d, or 4 g/d or placebo for 12 weeks. The EPA 4 g/d demonstrated a medium effect versus placebo. This dose may alleviate MDD in overweight individuals with elevated inflammatory markers. Further, decline in hs-CRP may be correlated with clinical response.