Polygenic scores in sleep research

Dear Editor, We read with attention the recent publication entitled “Genetic Risk Scores, Perceived Neighborhood Disorder, and Sleep Duration” by He et al. [1]. This is an interesting study with many strengths and an appealing and inspiring perspective from a socioecological standpoint; however, we would like to raise several important methodological considerations that may limit and temper the interpretation of its findings. First, the authors do not provide direct effect size estimates for their polygenic scores (PGS), which hampers the ability of the reader to evaluate the relevance of their results. While the results are highly significant due to the large sample size, the magnitude of the effects should also be evaluated. Based on the coefficients reported in Table 2, we estimate that the PGS for sleep duration explains approximately 0.15 percent of the variance in that model and 0.049 percent in the case of neighborhood disorder (see calculations below).