Choi WJ, Woo YS, Choi W, Lee J, Bahk W.  Defining “High Recurrence” of Depressive Episodes for Predicting Diagnostic Conversion from Major Depressive Disorder to Bipolar Disorder: A 5-year Retrospective Study.  Clin Psychopharmacol Neurosci 2024;22:364-369.  https://doi.org/10.9758/cpn.24.1183