title: Nitric oxide plasma/serum levels in patients with schizophrenia: a systematic review and meta-analysis.
abstract: For the last 40 years, schizophrenia has been considered to be the result primarily of a dysfunction in brain dopaminergic pathways. In this review, it is described and discussed findings concerning nitric oxide-mediated neurotransmission in schizophrenia. Studies were searched in PubMed, SciELO, and LILACS using the terms schizophrenia and nitric oxide plasma levels or nitric oxide serum levels, with no time limit. The reference lists of selected articles were also hand-searched for additional articles. From 15 potential reports, 10 were eligible to be included in the review and meta-analysis. These studies included a total of 505 patients with schizophrenia and 339 healthy volunteers. No significant difference was found between patients and healthy controls regarding total nitrite plasma/serum levels (effect size g = 0.285, 95%CI = -0.205 to 0.774, p = 0.254). However, when studies with patients under antipsychotic treatment were examined separately, there was a significant difference between patients and healthy volunteers (effect size g = 0.663, 95%CI = 0.365 to 0.961, p < 0.001), showing that patients under treatment have higher levels of plasma/serum nitric oxide than controls. These results suggest that antipsychotics increase nitric oxide plasma/serum levels and that the nitrergic pathway would be a fertile target for the development of new treatments for patients with schizophrenia.
authors: Department of Neuroscience and Behavior, Faculdade de Medicina, Universidade de São Paulo, Ribeirão Preto (SP), Brazil. j.p@usp.br
authors: João Paulo
authors: JP
authors: Maia-de-Oliveira
authors: Clarissa
authors: C
authors: Trzesniak
authors: Irismar R
authors: IR
authors: Oliveira
authors: Matthew J
authors: MJ
authors: Kempton
authors: Tatiana M N de
authors: TM
authors: Rezende
authors: Sandro
authors: S
authors: Iego
authors: Glen B
authors: GB
authors: Baker
authors: Serdar M
authors: SM
authors: Dursun
authors: João Paulo
authors: JP
authors: Machado-de-Sousa
authors: Jaime E C
authors: JE
authors: Hallak
mesh_terms: D014150:Antipsychotic Agents / Q000494:pharmacology; D003627:Data Interpretation, Statistical; D036262:Empirical Research; D006801:Humans; D009569:Nitric Oxide / Q000097:blood*; D012559:Schizophrenia / Q000097:blood* / Q000188:drug therapy / Q000503:physiopathology
chemical_list: D014150:Antipsychotic Agents; D009569:Nitric Oxide