Using GCTA-GREML methods46, the SNP-based heritability (h2SNP) estimates in UKB were consistent and significant across MDD subtypes, with h2SNP(SE) estimates of MDD = 0.20(0.04); rMDD = 0.20(0.03); fMDD = 0.22(0.06) and mMDD = 0.18(0.06). Due to the unrelated subset of individuals in GS:SFHS being markedly smaller than the full sample (nmax = 7 795), the heritability estimates were non-significant across all MDD definitions. Results from GCTA-GREML are shown for MDD subtypes in Supplementary Table 15. LDSR yielded lower h2SNP estimates than GCTA-GREML methods (Supplementary Table 16). This is to be expected as LDSR utilizes summary scores, which have usually been subjected to genomic control, as opposed to full SNP data.
