In this study, our emphasis is on harmonizing the analysis to maximize the number of studies to be included. The hope is that a large sample size will overcome limitations due to heterogeneity in measurements of depression and environment. This assumption is supported by many GWAS meta-analyses and studies which find many more genetic associations even when compromising on phenotyping, e.g. by considering anyone with a clozapine prescription a case, rather than a formal schizophrenia diagnosis (e.g. [44,45]). However, there are limitations to this approach. Although the analysis will be uniform, neither the phenotype nor the environment was measured in a consistent fashion in all studies.
