4.4. Limitations of This Study
MDD, Alzheimer’s disease
We executed the first pilot RCT nationwide which interrogated the effects of TPS on MDD. We can only, thus, use existing NIBS studies, such as on TMS and tDCS, to act as comparison for our findings. As both TMS and tDCS use non-invasive neuromodulation technology via electrical stimulation, the mechanism is still different from TPS, which uses ultrashort ultrasound waves in its stimulation of the human brain. Thus, our findings need to be interpreted with caution. In addition, there was only one uncontrolled pilot study that used fMRI, which confirmed the significant effects of TPS on cognition, memory, and executive function of patients with Alzheimer’s disease [