Choi JM, Yang JI, Kang SJ, Han YM, Lee J, Lee C, Chung SJ, Yoon DH, Park B, Kim YS.  Association Between Anxiety and Depression and Gastroesophageal Reflux Disease: Results From a Large Cross-sectional Study.  J Neurogastroenterol Motil 2018;24:593-602.  https://doi.org/10.5056/jnm18069