A hallmark of science is the ability of results to be replicated, a criterion that has been increasingly recognized in biological and psychological research.66 The original 2003 report of an interaction between 5-HTTLPR genotype and stress exposure on depression16 has remained controversial due to inconsistent results from replication efforts. Although some researchers have claimed a replication of the hypothesized interaction based on different stressors, different measures of depression, or different genetic models,25, 26 other attempts to replicate the finding have been negative.23, 24, 67 The goal of our study was to rigorously explore the extent to which the original report could be replicated and generalized using a structured collaborative meta-analysis.
