To the Editor: In their meta-analysis, Dr Risch and colleagues1 reported on gene-environment interactions in depressive disorders, focusing on the interaction between the serotonin transporter promoter polymorphism and life events. They stated that “the samples, study designs, measures, and analyses were highly divergent across studies, thereby limiting the comparability of the studies and their evidence regarding replication.” However, the authors did not address 2 other problems arising from the methodology of their meta-analysis.
Schwahn C, Grabe HJ. Gene-Environment Interactions and Depression. JAMA. 2009;302(17):1859-1862. doi:10.1001/jama.2009.1577