21. Cheng CM, Hong CJ, Lin HC, Chu PJ, Chen MH, Tu PC, et al. Predictive roles of brain-derived neurotrophic factor Val66Met polymorphism on antidepressant efficacy of different forms of prefrontal brain stimulation monotherapy: a randomized, double-blind, sham-controlled study. J Affect Disord 2022;297:353-359.