A Multicenter, Double-Blind, Double-Dummy, Placebo-Controlled, Randomized, Parallel Group Evaluation of the Efficacy and Safety of a Fixed-Dose of Talnetant Versus Placebo Versus Risperidone in Subjects With Schizophrenia

This study will evaluate whether talnetant (200mg, 400mg, 600mg) twice a day is effective compared to placebo and risperidone 1-3mg twice a day in treating the positive and negative symptoms of schizophrenia. Study subjects will be treated with study drug for up to 6 weeks and will then return for a follow-up visit 2 weeks later. About 275 patients with schizophrenia will be enrolled in this study.