Research on racial disparities in health could also benefit from the methodological and conceptual recommendations that have been made to advance future research on gene-environment interactions in general.146, 150 One of the key recommendations is the need for careful replication and meta-analyses. Given the large number of variants examined the probability of chance findings is high. Over the last decade, genetic association studies have created “one of the largest bodies of irreproducible results yet accumulated.”137 A meta-analysis of 370 studies that examined 36 genetic associations for various diseases found that the first published study typically suggests a stronger genetic effect than is found in subsequent studies.151 Sampling biases are potential contributors to this pattern. There has been particular interest in interactions between the serotonin transporter gene (5-HTTLPR) and stress in affecting depression but a recent meta-analysis of 14 studies that examined the interaction between this genotype and stressful life events in predicting depression found that although stress is associated with an increased risk of depression, there was no interaction evident between the genetic trait and stress.152 However, the studies varied
