Given 1) the established safety with short-term or long-term supplementation of Cr, 2) its potential usefulness in improving brain energy metabolism, 3) the reported abnormality in brain energy metabolism in MDD subjects, and 4) plausible association between depression and inflammatory mediators, we hypothesize that oral Cr augmentation will help reduce symptoms in MDD patients as well as normalize a deficit in brain energy metabolism and that improvement of MDD and brain energy metabolism will be correlated with inflammatory mediators changes.