In spite of the numerous studies on schizophrenia, its etiology and physiopathology remain unknown. Evidence suggests a possible implication of nitric oxide (NO) in schizophrenia. NO is a gas with unique chemistry and influences the release of neurotransmitters, learning, memory and neurodevelopment. Recent studies that investigated the role of NO in patients with schizophrenia found evidence that points to a disruption in NO-mediated neurotransmission in schizophrenia. Accordingly, we believe that the administration of sodium nitroprusside, an NO donor, will ameliorate schizophrenia symptoms.

Inclusion Criteria:

• Clinical diagnosis of schizophrenia
• Patients in an acute psychotic episode requiring full hospitalization

Exclusion Criteria:

• Significant medical conditions (heart, kidney, liver, thyroid or neurological diseases, hypovitaminosis B12, hyponatremia)
• Pregnancy
• Breastfeeding
• Previous hypersensitivity to sodium nitroprusside
• DSM-IV diagnosis of drug abuse or dependence