A Study of RO4917838 (Bitopertin) in Patients With Persistent, Predominant Negative Symptoms of Schizophrenia (WN25309)

Inclusion Criteria: * Adult patients, aged 18 years and above * Diagnosis of schizophrenia of paranoid, disorganized, residual, undifferentiated or catatonic subtype * Predominant negative symptoms * With the exception of clozapine, patients are on any of the available marketed atypical or typical antipsychotics (treatment with a maximum of two antipsychotics) Exclusion Criteria: * Evidence that patient has clinically significant, uncontrolled and unstable disorder (e.g. cardiovascular, renal, hepatic disorder) * Body Mass Index (BMI) of \<17 or \>40 kg/m2 * Depressive symptoms, defined as a score of 9 or greater on the Calgary Depression Rating Scale for Schizophrenia (CDSS) * A severity score of 3 or greater on the Parkinsonism item of the ESRS-A (Clinical Global Impression, Parkinsonism)