When examining the studies for the possibility of heterogeneity of effect—consistent with Figure 2, eTable 2, and eTable 3 available at http://www.jama.com)—we found no evidence of heterogeneity for the genotype alone (P=.68); however, we did find a significant degree of heterogeneity for life events alone (P<.001). Heterogeneity of the interaction was also not significant (P>.05), and none of the individual interaction coefficients was significantly deviant from the overall average.
