The primary features of schizophrenia and schizoaffective disorder are characterized by positive (inability to think clearly and distinguish reality from fantasy) and negative symptoms (reduction or absence of normal behavior or emotions). Other symptoms include reduced ability to recall and learn information, difficulty in problem solving or maintaining productive employment. Asenapine is an investigational drug that may help to correct the above characteristics of schizophrenia by altering the inbalance of brain hormones such as dopamine and serotonin. This is a 12-month trial that will test the efficacy and safety of asenapine using an active comparator (olanzapine) in the treatment of patients with schizophrenia. Patients who complete the 12-month trial will have the option of continuing on drug until the treatment code for the 12-month trial is unblinded.