Chunk #6 — Bias in a protocol for a meta-analysis of 5-HTTLPR, stress, and depression — Issue 1: “Primary Analysis Plan 2” to study lifetime depression does not allow for establishing temporal order between stress and depression
of life events that occurred after depression. Results showed empirically that unless the stress occurred before the depression, the GxE finding was not observed. Culverhouse et al. carefully and rightly emphasize the importance of matching the design features of a replication analysis as closely as possible to design features of the original publication. However, Plan 2 not only fails to match the design of the original publication, it includes a design feature that the original publication tested and advised against.
