Efficacy and Safety of AVE1625 as a Co-treatment With Antipsychotic Therapy in Schizophrenia

Inclusion Criteria: * Outpatients with diagnosis of schizophrenia (diagnosed ≤ 35 years of age). * Current treatment consisting exclusively of olanzapine, risperidone/paliperidone, quetiapine or aripiprazole monotherapy for at least 2 months. Exclusion Criteria: * Inpatient hospitalization within past 3 months. * Residence at the current address \< 3 months due to any instability in the disease. * Presence of depressive symptoms. * Past history of clinically significant violent behavior. * Substance dependence or abuse. * Pregnant or breast-feeding women or women not protected by effective contraceptive method of birth control. The investigator will evaluate whether there are other reasons why a patient may not participate.