Table 1.
Summary of the phenotypes and summary genetic data used in each direction in the Mendelian randomization (MR) analysis
| Phenotype | Sample size | NSNPsa | Units | Data source |
|---|---|---|---|---|
| Effect of MDD on MS | ||||
| MDD (exposure) | 2,114,426 (660,937 cases) | 98 | odds of MDD, adjusted for sex, age, genotyping array, and genetic PCs | Howard et al. (full meta-analysis) |
| MS (outcome) | 41,505 (14,802 cases) | 98 | – | IMSGC (discovery cohort) |
| Effect of MS on MDD | ||||
| MS (exposure) | 115,803 (47,429 cases) | 178 | odds of MS, adjusted for genetic PCs | IMSGC (full meta-analysis) |
| MDD (outcome) | 500,199 (170,756 cases) | 178 | – | Howard et al. (UKB and PGC only) |
| Multivariable MR | ||||
| BMI | 322,154 | 74 | SD increase in BMI, adjusted for age, age squared, sex and genetic PCs | GIANT consortium |
a
Number of independent SNPs included in the analysis after filtering.
BMI = body mass index, MDD = major depressive disorder, IMSGC= International MS Genetics Consortium, MS = multiple sclerosis, PCs = principal components, SNPs = single nucleotide polymorphism, SD= standard deviation, UKB = UK Biobank