Nitric Oxide’s Involvement in the Spectrum of Psychotic Disorders

Background: Recent findings suggest that dopaminergic abnormalities found in psychotic disorders may be secondary to nitric oxide dysfunctions. Nitric oxide seems to influence glutamatergic and dopaminergic neurotransmission, both of which have been associated with psychosis. Objective: To search and review published works which examined the influence of nitric oxide in psychotic disorders subjects. Method: The research was executed in the on-line collections of Pubmed and ISI Web of Science. The key aspects utilized were “Psychotic Disorders AND Nitric Oxide”, “Psychosis AND Nitric Oxide”,“Schizotypal Personality Disorder AND Nitric Oxide”, “Delusional Disorder AND Nitric Oxide”, “Brief Psychotic Disorder AND Nitric Oxide”, “Schizophreniform Disorder AND Nitric Oxide”, “Schizoaffective Disorder AND Nitric Oxide”, and “Schizophrenia AND Nitric Oxide”. Empirical works utilizing human subjects, published in the last 10 years, in English language were included. Results: Initially, the search yielded a total of 95 studies. Then, 39 were elected according to the inclusion requirements. The selected articles were divided into five groups: biochemical studies (n=15; 38.5%), genetic studies (n=11; 28.2%), postmortem studies (n=6; 15.4%), clinical trials (n=6; 15.4%), and case reports (n=1; 2.5%). The studies evaluated only schizophrenic or schizoaffective disorder subjects. The great majority of them found evidence of nitric oxide dysfunctions in psychosis. Conclusion: The results of the review strengthen the idea that nitric oxide has a key participation in psychotic disorders and deserves deeper investigation as a target for future pharmacological intervention.