AUTHOR=Wang Yuxia , Li Ou , Li Nana , Sha Zhongwei , Zhao Zhenghao , Xu Jian TITLE=Association between the BDNF Val66Met polymorphism and major depressive disorder: a systematic review and meta-analysis JOURNAL=Frontiers in Psychiatry VOLUME=14 YEAR=2023 URL=https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2023.1143833 DOI=10.3389/fpsyt.2023.1143833 ISSN=1664-0640 ABSTRACT=Study objectives

This meta-analysis analytically reviewed recent studies concerning the potential associations between the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism and susceptibility to major depressive disorder (MDD), with subgroup analyses for race and age.

Methods

Relevant case-control studies were systematically searched for in PubMed, Embase, the Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang, and Sinomed databases. A total of 24 studies were finally identified to have reported outcomes including alleles, dominant genes, recessive genes, homozygosity, and heterozygosity. Subgroup meta-analyses were performed based on participant age and ethnicity. Publication bias was represented by funnel plots. All meta-analyses of the randomized controlled trials included for evaluation were performed using RevMan5.3 software.

Results

The findings revealed no significant association between BDNF Val66Met polymorphism and MDD. However, the Met allele was found to be associated with genetic susceptibility to MDD among white populations on subgroup analysis (OR = 1.25, 95% CI: 1.05–1.48, P = 0.01). In the genetic model, dominant (OR = 1.40, 95% CI: 1.18–1.66, P = 0.0001), recessive (OR = 1.70, 95% CI: 1.05–2.78, P = 0.03), and homozygous (OR = 1.77, 95% CI: 1.08–2.88, P = 0.02) genes were all associated with MDD.

Conclusions

Despite the outcome limitations, this meta-analysis confirmed that the BDNF Val66Met polymorphism is a susceptibility factor for MDD in white populations.