Under standard assumptions, bivariate score regression produces unbiased estimates of genetic correlation, even in the presence of sample overlap65. Accordingly, to estimate the extent of genetic correlation between each of our phenotypes, and between our phenotypes and other phenotypes related to nicotine and alcohol use, we used standard procedures in LD Score Regression22. To be included in these analyses, variants were restricted to those present in HapMap3 with MAF>0.01. Standard errors were estimated with a block jackknife over all variants.
