Sodium nitroprusside treatment for psychotic symptoms and cognitive deficits of schizophrenia: A randomized, double-blind, placebo-controlled trial

Schizophrenia presents with a broad range of negative, positive, and cognitive symptoms, and comprehensive treatment is still a challenge. Sodium nitroprusside (SNP) has been reported to rapidly reduce psychotic symptoms and improve cognitive functions in patients with schizophrenia, providing a new possible direction for treatment. In this study, we tested whether SNP can improve psychotic symptoms and cognitive function in schizophrenia patients with longer disease history. This was a randomized, double-blind, placebo-controlled trial conducted between May 2016 and April 2017. Forty-two schizophrenia patients aged 18-45 years were recruited from Henan Province Mental Hospital. Baseline psychiatric symptoms were measured using the Positive and Negative Syndrome Scale (PANSS), and baseline cognitive functions were measured using the Wechsler Adult Intelligence Scale. Patients received two SNP or placebo infusions (0.5 μg/kg per min for 4 h) at a one-week interval. We reassessed psychiatric symptoms and cognitive functions using the same tests shortly after the first and second infusions and 4 weeks after the second infusion. We did not find any significant effect of SNP over placebo on psychotic symptoms or cognitive functions, although SNP was relatively well tolerated with a good safety profile.