Objective: Major depression (MD) is a condition associated with both hepatitis C virus (HCV) infection and pegylated interferon (IFN)-α treatment. IFN induces a depressive syndrome that is associated with an inflammatory profile. We aimed to investigate whether there is any specific alteration in plasma biomarkers associated with MD. Methods: HCV-monoinfected patients, with and without IFN treatment, were followed up for 18 months and went through structured psychiatric evaluation. We assessed plasma levels of brain-derived neurotrophic factor, tumor necrosis factor (TNF) and its soluble type 1 and type 2 receptors (sTNFR1 and sTNFR2, respectively), and adipokines (adiponectin, leptin and resistin) using ELISA. Results: Among the 50 patients included in the study, 14 were treated with IFN during the follow-up. Being older, not married, presenting higher body mass index, higher liver inflammatory activity, lower baseline adiponectin levels and use of IFN were associated with MD development. Higher levels of sTNFR1 during IFN treatment were associated with sustained virological response. The lack of a control group without HCV infection did not allow any assumption of a biomarker change exclusively due to the infection itself. Conclusion: Adiponectin may be a resilience biomarker for MD in HCV-infected patients.