text: Our findings suggest an @GENE$ of allelic variation in 5-@DISEASE$(1A) receptor expression on the development of interferon alfa-induced depression during antiviral treatment of chronic hepatitis C. Prediction models of interferon-induced depressive symptoms based on HTR1A variation offer a perspective for an antidepressant selective serotonin reuptake inhibitor prophylaxis in patients genetically at risk for interferon-induced depression.