Lurasidone Effects on Tissue Glutamate in Schizophrenia

Inclusion Criteria: * Subject at least 18 years old * Subject meets criteria diagnosis of schizophrenia or schizoaffective disorder. * Subject is not pregnant and is not planning pregnancy within the projected duration of the study. * Female subject who is of reproductive potential agrees to remain abstinent or use adequate and reliable contraception throughout the study * Subject is in good physical health on the basis of medical history, physical examination, and laboratory screening. * Eyesight corrected to 20-40 or better * Able to read, speak, and understand English\* Exclusion Criteria: * Any medications being used as mood stabilizers (i.e., anticonvulsants) * Subject currently has a clinically significant medical condition(s) that would pose a risk to the subject if they were to participate in the study or that might confound the results of the study. * Subject demonstrates evidence of acute/chronic hepatitis which is clinically significant * Subject has a history of malignancy \< 5 years prior * Subject has a history of neuroleptic malignant syndrome (NMS). * Subject has a history of alcohol or substance abuse within 3 months prior to screening or alcohol or substance dependence within 12 months prior to screening * Subject tests positive for drugs of abuse at screening. In the event a subject tests positive for cannabis, the investigator will evaluate the subject's ability to abstain from cannabis during the study. * Subjects diagnosed with type 1 diabetes * Subject has a prolactin concentration \> 200 ng/mL at screening * Subject has a history or presence of abnormal ECG which is clinically significant * Subject has a history of hypersensitivity to more than two distinct chemical classes of drug (e.g., sulfas and penicillins). * Subjects have received depot neuroleptics within 12 weeks prior to randomization. * Subject has a history of treatment with clozapine for refractory psychosis and/or subject has been treated with clozapine within 4 months of randomization. * Subject does not have a stable residence for the 3 months prior to randomization. * Subject requires treatment with any potent CYP3A4 inhibitors or inducers during the study. * Subject has received electroconvulsive therapy (ECT) within 90 days prior to * Subject has been randomized in a prior clinical trial of lurasidone. * History of serious head injury with unconsciousness for \>30 minutes