Stimulation techniques, such as vagus nerve stimulation, are a promising new approach for treatment-resistant depression. Most international studies have used fixed stimulation parameters or have varied the stimulation frequencies. Our retrospective examination of 2 parallel groups of 10 patients each compared low-strength/high-frequency vagus nerve stimulation parameters (≤1.5 mA, 20 Hz) with high-strength/low-frequency ( >1.5 mA, 15 Hz) parameters. We found a significant decrease in the Hamilton Rating Scale for Depression scores in patients who were treated using the low-strength/high-frequency stimulation parameters. In contrast, the scores of the patients treated with high-strength/low-frequency stimulation did not change.