We found strong evidence that a serotonin transporter promoter polymorphism (5-HTTLPR) moderates the relationship between stress and depression, with the less functional short (s) allele associated with increased stress sensitivity. Our results differ from the results of the two other meta-analyses that have explored this specific association. To test whether this difference in results was due to the expanded set of studies that we included or the different meta-analytic technique utilized, we applied our meta-analytic technique to the sets of studies used in the previous meta-analyses. With these limited set of studies, our meta-analytic technique produced the same non-significant results as the previous meta-analyses, suggesting that the difference in results between meta-analyses was due to the different set of included studies.
