title: Serum folate levels in schizophrenia: A meta-analysis.
abstract: To clarify the relationship between serum folate and schizophrenia (SZ) risk, the meta-analysis was conducted. PubMed, Embase, and Web of Science were searched without language restrictions. Weighted mean difference (WMD) as a summary statistic was used in this meta-analysis. Subgroup analyses by publication language (English and non-English), ethnicity (Caucasian, Asian, African, Latino, and mixed population), duration (acute, chronic, patients including both acute and chronic SZ, and not mentioned about either chronic or acute), measurement time (before drugs using and after drugs using), gender (male and female) and age (<50 years old and >50 years old) were performed. Power analysis was also conducted to detect the reliability of the meta-analyses' results. In summary, the subgroups which failed to detect significant decreased associations were always with lower statistic power and could not be confirmed. The results supported that decreased serum folate was associated with SZ risk in total studies and subgroups of English publications, Caucasians, Asians, acute SZ patients, measurement after drugs using in SZ patients, and age<50 with the great enough powers, respectively. In conclusion, the present meta-analysis found that folate deficiency is associated to SZ, and subgroups which did not reach enough statistical power need further investigation in the future.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Hebei Medical University, Shijiazhuang 050017, Hebei Province, China; Library, Hebei Medical University, Shijiazhuang 050017, Hebei Province, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Novelty Retrieval, Institute of Hebei Medical Information, Shijiazhuang 050071, Hebei Province, China.
authors.forename: Jun-Xia
authors.initials: JX
authors.lastname: Zhai
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Hebei Medical University, Shijiazhuang 050017, Hebei Province, China. Electronic address: dwliu1956@163.com.
authors.forename: Dian-Wu
authors.initials: DW
authors.lastname: Liu
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D005006:Ethnicity; D005260:Female; D005492:Folic Acid / Q000097:blood*; D005494:Folic Acid Deficiency / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012307:Risk Factors; D012559:Schizophrenia / Q000097:blood* / Q000209:etiology; D012737:Sex Factors; D013997:Time Factors
chemical_list: D005492:Folic Acid
keywords: Folate; Meta-analysis; Schizophrenia; Serum