Daghlas I, Lane JM, Saxena R, et al. - Researchers herein sought to determine the correlation of genetically proxied morning diurnal preference with depression risk using mendelian randomization. In this 2-sample mendelian randomization study, they performed analysis of data from approximately 840,000 adults of European ancestry. Earlier sleep timing patterns were noted to be linked with lower risk of major depressive disorder. Overall, data indicate correlation of sleep timing patterns with the risk of major depressive disorder. They recommend examining these patterns further in randomized clinical trials of sleep interventions.