Based on significant and robust heritability estimates (h2 z>4), 1,457 traits from available GWAS summary statistics were sufficiently powered to assess genetic correlation with MDD-META. After multiple testing correction (p = 0.05/1,457 trait pairs = 3.43×10−5), 669 phenotypes were significantly genetically correlated with MDD-META (Figure 2 Lower Panel, Supplementary File 1). The most significant phenotypic correlations with MDD-META from each depressive trait category were: (i) depressive symptoms (Social Science Genetic Association Consortium, SSGAC) rg =0.943±0.029, p=1.76×10−228, (ii) depression medications (FinnGen) rg =0.890±0.063, p=6.22×10−45, (iii) major depressive disorder (Psychiatry) rg =1.02±0.017, p<1.39×10-, and (iv) frequency of tiredness/lethargy in last 2 weeks (UKB Field ID 2080) rg =0.684±0.018, p<1.39×10-300. No brain imaging phenotype met corrected significance criteria for genetic correlation with MDD-META; the most significantly genetically correlated brain imaging phenotype, using data provided from the Oxford Brain Imaging Genetics (BIG) project,14 relative to MDD-META was left subcallosal cortex grey matter volume (BIG Field ID 0078) rg =0.205±0.061, p=9.00×10-4.
