title: Is there any association between Toxoplasma gondii infection and bipolar disorder? A systematic review and meta-analysis.
abstract: The relationship between Toxoplasma gondii infection and the development of bipolar disorder (BD) has long been investigated, yet to date it is still poorly understood and documented. The aim of this review is to derive a summary estimate of the strength of the association between infection with T. gondii and BD from the available published studies.
  
  
  
  A systematic review was performed using PubMed, LILACS, PsycINFO, and Embase databases. Studies which included a proportion of seropositive BD patients and controls were further examined in a meta-analysis.
  
  
  
  One hundred eighteen citations were initially retrieved. Thirteen studies were included in our systematic review. Eight out of these thirteen studies were included in our meta-analysis. Statistical analyses showed that T. gondii infection is associated with with BD (OR=1.26).
  
  
  
  Small sample size was the major limitation among the studies that carried out serological analyses. In addition, the available studies did not have enough information on disease status/severity or type of bipolar disorder. Also, it was not possible to analyze pregnancy status or perinatal infection. Future studies addressing the aforementioned topics are clearly needed.
  
  
  
  Despite heterogeneous results, patients with BD are more likely to be infected by T. gondii than controls. Early T. gondii infection might predispose the development of BD. T.gondii infection is becoming clinically relevant in psychiatric disorders and future mechanistic studies are required to elucidate the underlying pathophysiological mechanisms.
authors.affiliation: Biology Department, The College of Idaho, Caldwell, Idaho, USA; Neuroscience Division, Interdisciplinary Laboratory of Medical Investigation, School of Medicine, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: João Luís Vieira Monteiro
authors.initials: JLVM
authors.lastname: de Barros
authors.affiliation: Neuroscience Division, Interdisciplinary Laboratory of Medical Investigation, School of Medicine, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Izabela Guimarães
authors.initials: IG
authors.lastname: Barbosa
authors.affiliation: Neuropsychiatry Program, Department of Psychiatry and Behavioral Sciences, McGovern School of Medicine, University of Texas Health Science Center, Houston, TX, USA.
authors.forename: Haitham
authors.initials: H
authors.lastname: Salem
authors.affiliation: Neuroscience Division, Interdisciplinary Laboratory of Medical Investigation, School of Medicine, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil; Neuropsychiatry Program, Department of Psychiatry and Behavioral Sciences, McGovern School of Medicine, University of Texas Health Science Center, Houston, TX, USA.
authors.forename: Natalia Pessoa
authors.initials: NP
authors.lastname: Rocha
authors.affiliation: Neuroscience Division, Interdisciplinary Laboratory of Medical Investigation, School of Medicine, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Arthur
authors.initials: A
authors.lastname: Kummer
authors.affiliation: Neuropsychiatry Program, Department of Psychiatry and Behavioral Sciences, McGovern School of Medicine, University of Texas Health Science Center, Houston, TX, USA.
authors.forename: Olaoluwa O
authors.initials: OO
authors.lastname: Okusaga
authors.affiliation: Neuropsychiatry Program, Department of Psychiatry and Behavioral Sciences, McGovern School of Medicine, University of Texas Health Science Center, Houston, TX, USA.
authors.forename: Jair C
authors.initials: JC
authors.lastname: Soares
authors.affiliation: Neuroscience Division, Interdisciplinary Laboratory of Medical Investigation, School of Medicine, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil; Neuropsychiatry Program, Department of Psychiatry and Behavioral Sciences, McGovern School of Medicine, University of Texas Health Science Center, Houston, TX, USA; Harris County Psychiatric Center, Department of Psychiatry and Behavioral Sciences, McGovern School of Medicine, University of Texas Health Science Center, Houston, TX, USA. Electronic address: Antonio.L.Teixeira@uth.tmc.edu.
authors.forename: Antonio Lucio
authors.initials: AL
authors.lastname: Teixeira
mesh_terms: D001714:Bipolar Disorder / Q000150:complications / Q000453:epidemiology / Q000523:psychology*; D005260:Female; D006801:Humans; D011247:Pregnancy; D014123:Toxoplasmosis / Q000150:complications / Q000453:epidemiology / Q000523:psychology*
keywords: Bipolar disorder; Immunology; Inflammation; Toxoplasma gondii