Higbee DH, Granell R, Hemani G, et al. - This study was intended to ascertain whether lung function or risk of COPD causes reduced cognitive function using Mendelian randomization (MR). Researchers used single nucleotide polymorphisms from genome-wide association studies of lung function and COPD as exposures. The study analyzed their effect on general cognitive function in a sample of 132,452 individuals. They further conducted multivariable MR, analyzing the effect of lung function before and after conditioning for covariates. There was no evidence that reduced lung function or COPD causes reduced cognitive function. Previous observational studies probably affect residual confounding. As per the findings, research efforts should focus on shared risk factors for reduced lung function and cognition, rather than lung function alone as a modifiable risk factor.