Association between Catechol-O-Methyltransferase Val158Met (158G/A) Polymorphism and Suicide Susceptibility: A Meta-analysis

Background: Common functional Val158Met polymorphism in the Catechol-O-methyltransferase (COMT) gene may have an impact on an individual’s susceptibility to suicide, but individually published results are inconclusive. Therefore, we performed this meta-analysis to provide a more precise estimation of the association between COMT 158G/A (COMT Val158Met) polymorphism and suicide susceptibility. Study design: A cross-sectional study. Methods: This systematic review and meta-analysis is a comprehensive literature search of PubMed, Scopus, Web of Science and Google Scholar databases was conducted on case-control studies published up to Mar 2017. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Results: We identified 14 eligible case-control studies, including 2353 suicide attempters and 2593 controls. The pooled results indicated that COMT 158G/A (COMT Val158Met) polymorphism was not significantly associated with increased overall suicide risk. The same results were revealed based on ethnicity, Hardy–Weinberg equilibrium (HWE) status and genotyping technique. However, there was significant association between COMT Val158Met polymorphism and suicide risk among females under the homozygote (AA vs. GG: OR=1.829, 95% CI=1.158-2.889, P=0.010) and recessive (AA vs. AG +GG: or = 1.787, 95% CI=1.195, 2.671, P=0.005) models, but not among males. Conclusions: COMT 158G/A (COMT Val158Met) polymorphism was associated with suicide susceptibility only in females.