A Functional Serotonin Transporter Gene Polymorphism and Depressive Effects Associated With Interferon-α Treatment

Background Interferon-alpha (IFN- α ) treatment frequently induces depression, potentially leading to early dose reductions or a shorter duration of treatment, which can adversely affect outcomes, including quality of life. Objective Defining relevant risk factors for IFN- α -induced depression is essential in order to identify prophylactic treatment strategies. Method The authors examined whether a functional polymorphism (5-HTTLPR) in the gene encoding the serotonin transporter moderates IFN- α -induced depressive symptoms in 1,015 patients with chronic hepatitis C (CHC) receiving pegylated IFN- α and ribavirin. Depressive symptoms were assessed at baseline, 12 weeks, and 20 weeks of treatment Results Depression symptoms increased during antiviral treatment; 5-HTTLPR genotype moderated IFN- α -induced depression symptoms in both non-Hispanic Caucasians and Hispanic patients, although the opposite risk allele was associated with depression in the two populations. Conclusion 5-HTTLPR may moderate risk for the development of depressive symptoms during IFN- α therapy for CHC in a population-specific manner.