Correlation investigation between BDNF (Val66Met/rs6265) polymorphism and attention deficit hyperactivity disorder susceptibility in Chinese mainland population: a meta-analysis

This meta-analysis evaluated the association between the Val66Met polymorphism of brain-derived neurotrophic factor (BDNF) and the susceptibility to attention deficit hyperactivity disorder (ADHD) in the Chinese mainland population. Eligible documents were selected from online databases including PubMed, Embase, Cochrane Library, CNKI, Wanfang and CBM (updated to 15 October 2023). The evaluation of study quality was conducted according to guidelines of Newcastle-Ottawa Scale. Basic features of patients, OR and 95% CI were retrieved to assess the correlation between ADHD susceptibility and Val66Met polymorphism in four genetic models: allele genetic model (mutation (A) vs. wild-type (G)), additive genetic model (AA vs. GG and AG vs. GG), recessive genetic model (AA vs. AG+GG) and dominant genetic model (AA+AG vs. GG). This study included totally four studies for subsequent meta-analysis. The results indicated that the correlation between ADHD susceptibility and Val66Met polymorphism in A vs. G (OR = 0.8840, 95%CI: [0.6696-1.1672], p = 0.3846), AA vs. GG (OR = 0.8436, 95%CI: [0.5432-1.3102], p = 0.4490), AA+AG vs. GG (OR = 0.8602, 95%CI: [0.6497-1.1391], p = 0.2933), AG vs. GG (OR = 0.9132, 95%CI: [0.7810-1.0679], p = 0.2556) and AA vs. GG+AG (OR = 1.0315, 95%CI: [0.8789-1.2105], p = 0.7044) was not significant. Egger's test and sensitivity analysis demonstrating the reliability and stability our conclusions, respectively. BDNF Val66Met polymorphism did not contribute to the susceptibility of ADHD in Chinese mainland population.