Adjunctive vagus nerve stimulation for treatment-resistant depression: a preliminary study.

BACKGROUND: This study is the first to assess the safety and therapeutic efficacy of vagus nerve stimulation (VNS) as an adjunctive treatment for Chinese patients suffering from treatment-resistant depression (TRD). METHODS: A total of seven patients with TRD underwent surgical implantation of a VNS device were followed over a 9-month period. The 24-item Hamilton Rating Scale for Depression (HAMD-24) and the 14-item Hamilton Anxiety Scale (HAMA) were used to assess depressive and anxiety symptoms, respectively. Neurocognitive function was measured with the Wechsler Adult Intelligence Scale (WAIS) and the Wechsler Memory Scale (WMS). RESULTS: After 3 months of treatment with VNS, the antidepressant response and remission rates were 42.9% and 28.6%, respectively. After 9 months of treatment with VNS, the response and remission rates increased to 85.7% and 57.1%, respectively. Significant time main effects were identified for HAMD-24 scores, HAMA scores, the WMS memory quotient, and the full intelligence quotients measured with the WAIS (all ps < 0.05). The most frequent adverse effects of VNS treatment were voice alteration (100%) and cough frequency increase (71.4%). CONCLUSION: This preliminary study indicated that adjunctive VNS was effective and safe in treating Chinese patients who were suffering from TRD, and its efficacy increased with time.Key pointsThere is positive evidence to support the role of VNS as an adjunctive treatment in Chinese patients with TRD.The antidepressant efficacy of adjunctive VNS for Chinese patients with TRD increased with time.The most frequent adverse effects of VNS treatment were voice alteration and cough frequency increase.

Adjunctive Vagus Nerve Stimulation for Treatment-Resistant Depression: a Quantitative Analysis.

Vagus nerve stimulation (VNS) has been increasingly studied in treating treatment-resistant depression (TRD), but the findings have been mixed. This updated meta-analysis was conducted to examine the efficacy and safety of adjunctive VNS for TRD. Controlled studies reporting on the efficacy and safety of adjunctive VNS for TRD were screened, identified and analyzed. Standardized mean difference (SMD), risk ratio (RR) and their 95% confidence intervals (CIs) were analyzed using RevMan version 5.3. Three controlled studies with a total of 1048 patients with TRD compared VNS (n = 622) with control (n = 426) groups. Only one study was rated as 'high quality' using the Jadad scale. Adjunctive VNS was significantly superior to the control group regarding study-defined response [SMD:1.96 (95%CI:1.60, 2.40), P < 0.00001, I2 = 0%]. Patient-reported voice alteration occurred more frequently with adjunctive VNS for patients with TRD. No significant group differences were found regarding discontinuation due to any reason [RR:0.50 (95%CI:0.12, 2.09), P = 0.34, I2 = 85%]. Adjunctive VNS appeared to be effective and relatively safe treatment for TRD. Further randomized controlled trials are needed to confirm the efficacy and safety of VNS for TRD.