 The purpose of this study is to investigate the effect of steady-state telaprevir TVR 750 mg q8h 3 times a day, every 8 hours on the steady-state pharmacokinetics of escitalopram 10 mg q.d. once a day, and vice versa. Steady state is a term which means that the drug has been given long enough so that the plasma concentrations will remain the same with each subsequent dose. TVR is being investigated for the treatment of chronic hepatitis C virus HCV infection. Pharmacokinetics pk means how the drug is absorbed into the bloodstream, distributed in the body and eliminated from the body. 