High-definition transcranial direct current stimulation (HD-tDCS) as augmentation therapy in late-life depression (LLD) with suboptimal response to treatment—a study protocol for a... oleh Sze Ting Joanna Ngan, Lap Kei Chan, Wai Chi Chan, Linda Chiu Wa Lam, Wan Kei Li, Kelvin Lim, Ego Or, Pui Fai Pang, Ting Keung Poon, Mei Cheung Mimi Wong, Ying King Anna Wu, Pak Wing Calvin Cheng