Table 1 summarizes the nine published genome-wide association studies for MD. GWASs are typically carried out in two stages: a discovery phase, in which the entire genome is screened, and a replication phase, in which a subset of SNPs are tested in an independent cohort. Some studies report the replication and discovery results separately; others combine the p values of all studies (including the discovery sample) in a meta-analysis. Information on sample sizes for the two phases is shown in Table 1.Table 1Summary of Genome-wide Association Studies of Major DepressionSample OriginSampleCasesControlsSNPsPhenotypeMarkerORp ValuePositionLewis et al., 2010UKDiscovery1,6361,594471,747RMDrs94167420.7191.30 × 10−7chr10:60542444UKMeta1,4181,918––rs6061491.2482.57 × 10−6chr1:193921298Muglia et al., 2010EuropeMeta (two samples)1,3591,782494,678RMDrs42380100.585.80 × 10−6chr12:4118067Sullivan et al., 2009NetherlandsDiscovery1,7381,802435,291MDrs27151480.797.70 × 10−7chr7:82449785NetherlandsReplication6,0795,893––rs2715148NA8.20 × 10−1chr7:82449785Shyn et al., 2011U.S.Discovery1,2211,636382,598RMD 901; MD 735rs124628860.761.73 × 10−6chr19:29263440U.S.Meta3,9573,428––rs11066341.2956.78 × 10−7chr8:20065799Shi et al., 2011U.S.Discovery1,0201,636671,421RMD 1,000; MD 20rs170774501.611.83 × 10−7chr18:65285279Wray et al., 2012Australia/Europe/U.S.Discovery2,4313,6731,251,157RMD 1,145; MD 1,286rs1823580.788.80 × 10−6chr1:97462900Australia/Europe/U.S.Meta5,7636,901––rs124469561.221.10 × 10−6chr16:73501786Ripke et al., 2013bAustralia/Europe/U.S.Discovery9,2409,5191,235,109RMD/MDrs115799640.8461.00 × 10−7chr1:224538690Australia/Europe/U.S.Replication6,78350,695––rs19692531.0494.79 × 10−6chr3:183876262Kohli et al., 2011Europe/U.S.Discovery353366365,676MD/RMDrs15458432.845.53 × 10−8chr12:84563818Europe/U.S.Replication3,73810,635––rs15458431.3151.40 × 10−9chr12:84563818Rietschel et al., 2010GermanDiscovery6041,364491,238MDrs27654931.452.26 × 10−7chr1:157797750GermanMeta1,0131,905––rs77139170.751.48 × 10−6chr5:78828999This table gives the number of cases and controls for each GWAS and summarizes results. The sample sizes listed
