Systematic Reviews
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Psychiatr. Mar 22, 2015; 5(1): 154-159
Published online Mar 22, 2015. doi: 10.5498/wjp.v5.i1.154
Brain-derived neurotrophic factor levels in first episode of psychosis: A systematic review
Alba Toll, Anna Mané
Alba Toll, Anna Mané, Institut de Neuropsiquitria i Addiccions, Parc de Salut Mar, 08003 Barcelona, Spain
Alba Toll, Anna Mané, Fundació Institut Mar d’Investigacions Médiques, Hospital del Mar, 08003 Barcelona, Spain
Anna Mané, Centro de Investigación Biomédica en Red de Salud Mental, 08003 Barcelona, Spain
Author contributions: Toll A and Mané A performed the systematic review and wrote the manuscript.
Conflict-of-interest: The authors decalre they do not have any conflict of interest regarding the present article.
Data sharing: Technical appendix, statistical code, and dataset are available from the at Dryad repository, who will provide a permanent, citable and open-access home for the dataset.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Alba Toll, Privat, MD, Fundació Institut Mar d’Investigacions Médiques, Hospital del Mar, Passeig Martítim 25-29, 08003 Barcelona, Spain. 61048@parcdesalutmar.cat
Telephone: +34-93-2483000 Fax: +34-93-248354
Received: September 29, 2014
Peer-review started: October 1, 2014
First decision: November 27, 2014
Revised: January 8, 2015
Accepted: January 30, 2015
Article in press: February 2, 2015
Published online: March 22, 2015
Processing time: 174 Days and 16.3 Hours
Abstract

AIM: To systematically review studies measuring peripheric brain-derived neurotrophic factor (BDNF) levels on first-episode psychosis patients and variables related to them.

METHODS: A systematic search was made of articles published in the Medline database from 2002 up to June 2014. Included are original studies that report enzyme-linked immunosorbent assay measurement of BDNF levels in serum or plasma in patients with a diagnosis of first episode psychosis (FEP) and age- and gender- matched healthy controls.

RESULTS: Of the initially identified 147 articles, only 18 satisfied the inclusion criteria. Of this, 15 found a significant reduction in patients with FEP compared with age- and gender - matched controls.

CONCLUSION: Peripheral BDNF levels are generally reduced in FEP patients. There are some factors that may influence BDNF levels that need to be further studied. Furthermore, a future meta-analysis in this topic is needed.

Keywords: Brain-derived neurotrophic factor; Psychosis

Core tip: Brain-derived neurotrophic factor (BDNF) has an important role during brain development and various studies have reported altered peripheral BDNF levels in schizophrenia, but findings are inconsistent. Some studies have been carried out specifically in first episode patients to address this issue. In the present study we have systematically reviewed studies measuring BDNF levels in first episode psychosis (FEP) patients compared to healthy controls and variables related to them. Most studies report reduced BDNF levels in FEP patients but some factors that may influence BDNF levels need to be further studied.