Active VNS increases likelihood of meaningful improvement in suicidal ideation with OR 1.43Active vagus nerve stimulation may reduce suicidal thoughts in depression

This randomized controlled trial investigated the efficacy of adjunctive active vagus nerve stimulation (VNS) compared to sham VNS in a population of 463 participants with nonpsychotic major depressive disorder. The cohort specifically consisted of individuals who experienced insufficient benefit from at least 4 adequate antidepressant trials in their current episode, characterizing them as having markedly treatment-resistant depression. A critical component of the study population was the presence of baseline suicidal ideation (SI).

The study design utilized an active VNS plus treatment as usual intervention group compared against a sham VNS plus treatment as usual control group. The evaluation period for primary and secondary outcomes extended over 10 to 12 months, allowing for a longitudinal assessment of the impact of VNS on suicidal ideation.

The primary outcome was the likelihood of meaningful improvement in suicidal ideation, defined as a CSI score change of at least 3 among individuals with baseline SI. The results indicated that active VNS was superior to sham VNS over 10 months of evaluation, with an odds ratio (OR) of 1.43 (95% CI, 1.004-2.021; p <.05). This suggests a statistically significant increase in the likelihood of improvement for those receiving active stimulation.

Secondary outcomes included SI remission, defined as a CSI score of 2 or less between months 10 and 12. In this metric, active VNS was also superior to sham VNS, yielding an OR of 1.67 (95% CI, 1.007-2.763; p <.05). These results indicate that patients receiving active stimulation were more likely to achieve remission from suicidal ideation compared to those in the sham group.

Regarding safety and tolerability, the study reported that VNS did not significantly worsen suicidal ideation in participants regardless of their baseline status. Specific data regarding adverse events, serious adverse events, or discontinuation rates were not reported in the provided documentation. The findings suggest that the intervention is tolerable in this specific population.

While these results are promising for the management of treatment-resistant depression (TRD) with suicidal ideation, the study is characterized as an exploratory study. This classification implies that while the data shows a clear statistical advantage for active VNS over sham, the evidence base is still developing. The findings provide a specific signal for adjunctive therapy in a difficult-to-treat population.

Methodological limitations include the exploratory nature of the trial and the lack of reported data on specific adverse events or discontinuation rates. These gaps mean that while the primary and secondary outcomes are statistically significant, the full safety profile is not fully detailed in this report. Clinical implications suggest that active VNS may reduce SI and potentially induce SI remission in patients with chronic TRD. However, clinicians should note that these results are from an exploratory study and the potential induction of SI remission should be interpreted with caution.

Questions remain regarding the long-term durability of these effects beyond 12 months and the specific nature of any side effects not captured in the primary outcome reporting. Further investigation is needed to establish a definitive clinical protocol for VNS integration into standard care for TRD.