Inclusion Criteria:  Having a DSM-V diagnosis of Schizophrenia or schizoaffective disorder with <5 years from the onset of psychosis Having up to 2 years of lifetime exposure to antipsychotics Having total score of >65 on the Positive and Negative Syndrome Scale (PANSS) with a score of >4 on 1 or more PANSS items (delusions, conceptual disorganization, hallucinatory behavior, suspiciousness, or unusual thought content) Having English proficiency Being competent and willing to give informed consent  Exclusion Criteria:  Having substance dependence or abuse within the past 6 months Having history of retinal disease; myopia >4.0 diopters; symptomatic orthostatic hypotension Any change of psychotropic medications within the previous 4 weeks Currently taking clozapine Having prior history of intolerance to Sodium Nitroprusside Having treatment with medications that may interfere with the metabolism or excretion or effects of Sodium Nitroprusside Being pregnancy/breast feeding Having unstable major medical (renal, hepatic, or cardiac) or neurologic illness Having significant inflammatory or immune conditions Having treatment with anti-inflammatory drugs, hormones or immunosuppressant agents in the 6 months before study entry.