IFNA1 and major depressive disorder: Previous studies have shown that treatment-naïve HCV patients treated with RBV and IFN experience a significant PRO impairment.[13,14] In particular, the use of IFN causes substantial side effects, including debilitating ones such as severe depression, which, in turn, affect patients’ ability to sustain treatment long enough to obtain a cure whether through medical discontinuation or through patients’ nonadherence.