The decision of how indirect a replication attempt can be in order to be included in a review or meta-analysis is critical for gauging whether a finding has been supported in the literature. With respect to the interaction of 5-HTTLPR and stressful life events on depression, a meta-analysis by Munafo et al. (38) and subsequent meta-analysis by Risch et al. (5) examined results and/or data from 14 overlapping but not identical replication attempts and failed to find evidence supporting the original interaction reported by Caspi et al. (17). However, a much more inclusive meta-analysis by Karg et al. (39) looking at 56 replication attempts found evidence that strongly supports the general hypothesis that 5-HTTLPR moderates the relationship between stress and depression. Karg et al. argue that these contradictory conclusions were mainly caused by the different sets of studies included in the three analyses. Karg et al. included studies that Munafo et al. (38), Risch et al. (5), and we, in this report, consider to be indirect replications. For example, Karg et al. included studies investigating a wide range of alternative
