Association between resilience and a functional polymorphism in the serotonin transporter (SLC6A4) gene: A meta-analysis.

Resilience is a mechanism used by humans to adapt to adverse situations. It is a protective factor against mental health problems. This process can be influenced by environmental and genetic factors. Several genes have been associated with interindividual differences in resilience levels, but the results are inconclusive. Therefore, the aim of this meta-analysis was to evaluate the effect of a functional polymorphism (5-HTTLPR) in the SLC6A4 gene on resilience levels. A search in PubMed, HugeNavigator and Google Scholar databases was carried out and 16 studies about the association of 5-HTTLPR polymorphism and resilience in humans were identified. The OpenMeta[Analyst] program was employed to perform statistical analysis using a random-effects model. The final analysis included 9 studies, for a total of 4,080 subjects. Significant results were found when the standardized mean differences (SMD) of LL and SL carriers were compared, (SMD: -0.087 (confidence interval: -0.166 to -0.008; I 2 : 0 %); P value: 0.031). A significant result was also found in an analysis comparing SS/SL versus LL genotypes (SMD: -0.231; confidence interval: -0.400 to -0.061, P value: 0.008; I 2 : 0 %). This is the first meta-analysis performed to identify the pooled association of a functional polymorphism in the serotonin transporter gene and resilience. The current results suggest that the L/L genotype is associated with resilience. Further studies are necessary to elucidate the role of genetics on the resilience mechanisms.