A Study in Schizophrenic Patients

Inclusion Criteria: * Diagnosis of schizophrenia as defined in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR; APA 2000) (Disorganized, 295.10; Catatonic, 295.20; Paranoid 295.30; or Undifferentiated, 295.90) and confirmed by the Structured Clinical Interview for DSM-IV-TR (SCID) * Non pregnant female participants who agree to use acceptable birth control * At entry to the study must be considered moderately ill in the opinion of the investigator * 1 year history of Schizophrenia prior to entering the study * At study entry participants with a history of antipsychotic treatment must have a lifetime history of at least one hospitalization for the treatment of schizophrenia, not including the hospitalization required for study based on the investigator's clinical judgment. Participants who have never taken antipsychotic treatment may enter the study even without a history of hospitalization * At study entry participants with a history of antipsychotic treatment must have a history of at least one episode of illness exacerbation requiring an intensification of treatment intervention or care in the last 2 years, not including the present episode of illness. Participants who have never taken antipsychotic treatment may enter the study without a past history of illness exacerbation and intensification of treatment in the last 2 years * At study entry participants must have experienced an exacerbation of illness within the 4 weeks prior to entering the study, leading to an intensification of psychiatric care in the opinion of the investigator. If exacerbation occurs in participants who are presently hospitalized, the participants must not have been hospitalized longer than 60 days at entry of the study Exclusion Criteria: * Participated in any clinical trial with any pharmacological treatment intervention for which they received a study-related medication in the 6 months prior to visit 1 * Previously completed or withdrawn from this study, or any other study investigating LY2140023 or any predecessor molecules with glutamatergic activity * Have any known history of receiving treatment with clozapine at any dose, as determined at baseline * Have received treatment with a depot formulation of an antipsychotic medication within the 6 months prior entering the study * Participants who are currently suicidal * Females who are pregnant, nursing, or who intend to become pregnant within 30 days of completing the study * Participants with uncorrected narrow-angle glaucoma, uncontrolled diabetes, certain diseases of the liver, renal insufficiency, untreated thyroid condition or other serious or unstable illnesses * Have a history of one or more seizures, except for those who experienced a single simple febrile seizure between ages 6 months and 5 years * Participants are excluded if their biological father, mother, brother, sister, or child has a history of idiopathic epilepsy * Within 1 year of study enrollment, participants have a history of central nervous system infection, uncontrolled migraine, transient ischemic attack (TIA), or head trauma with loss of consciousness or a post-concussive * Participants are excluded if they have a lifetime history of any of the following: * head trauma, stroke, or central nervous system (CNS) infection with persistent neurological deficit (focal or diffuse); * brain surgery; * an electroencephalogram with paroxysmal (epileptiform) activity, or * brain structural lesion, including developmental abnormalities, as determined by examination or previous neuroimaging studies that are consistent with a diagnosable neurological disease or syndrome * Electroconvulsive therapy (ECT) within 3 months of entering the study or who will have ECT at any time during the study * Leukopenia * Medical history of Human Immunodeficiency Virus positive (HIV+) status * Higher than normal blood prolactin levels * Certain electrocardiogram results