Psychiatric symptoms including depression and anxiety are commonly reported in CHC patients treated with IFN, which is a major reason for discontinuing IFN therapy (Zdilar et al., 2000; Dieperink et al., 2003; Horikawa et al., 2003; Kraus et al., 2003; Gleason et al., 2007). This evidence concerns the gene IFNA1 and cryohydrocytosis.