We identified seven cohorts that used a range of methods to ascertain cases with major depression (described in detail in Table 1, Supplementary Tables 1–3). The methods used by these cohorts were extensively reviewed drawing on the breadth of expertise in the PGC, and we assessed the comparability of the cohorts using genomic data. We use “MDD” to refer to directly evaluated subjects meeting standard criteria for major depressive disorder and use “major depression” where case status was determined using alternative methods as well as to the phenotype from the full meta-analysis.
