Background: Depression is one of the main reasons for treatment withdrawal and failure in chronic hepatitis C patients treated with interferon. Antidepressants are useful for its treatment, but whether they can also be used for prevention has yet to be established. Method: To evaluate the efficacy and safety of escitalopram for preventing interferon alfa-2a-induced depression, we conducted an investigator-initiated multicenter, randomized, double-blind, placebo-controlled trial in 133 chronic hepatitis C patients without baseline mental disorders who were randomly assigned to receive escitalopram or placebo during the first 12 weeks of treatment. Primary efficacy outcomes were the development of DSM-IV major depression and scores on the Montgomery-Asberg Depression Rating Scale (MADRS) and the Hospital Anxiety and Depression Scale (HADS). Primary safety end points were biochemical and virological responses. Patients were recruited between March 2005 and July 2006. Results: Rates of major depression were low (5.4%) and did not differ between placebo (3.2%) and escitalopram (7.6%). MADRS and HADS scores significantly increased during treatment (P < .001 and P = .028, respectively), but there were no differences between treatment groups. Sustained virological response was achieved by 69.2% of patients, 70.4% in the placebo group and 67.9% in the escitalopram group. Conclusions: Findings do not support the use of an antidepressant to prevent interferon-induced depression during the first 12 weeks of treatment in chronic hepatitis C patients at low psychiatric risk. Future studies should be directed to subpopulations of patients at high psychiatric risk. © Copyright 2010 Physicians Postgraduate Press, Inc.