Elsevier

Biological Psychiatry

Volume 58, Issue 5, 1 September 2005, Pages 364-373
Biological Psychiatry

Original article
A One-Year Comparison of Vagus Nerve Stimulation with Treatment as Usual for Treatment-Resistant Depression

https://doi.org/10.1016/j.biopsych.2005.07.028Get rights and content

Background

Previous reports have described the effects of vagus nerve stimulation plus treatment as usual (VNS+TAU) during open trials of patients with treatment-resistant depression (TRD). To better understand these effects on long-term outcome, we compared 12-month VNS+TAU outcomes with those of a comparable TRD group.

Methods

Admission criteria were similar for those receiving VNS+TAU (n = 205) or only TAU (n = 124). In the primary analysis, repeated-measures linear regression was used to compare the VNS+TAU group (monthly data) with the TAU group (quarterly data) according to scores of the 30-item Inventory of Depressive Symptomatology–Self-Report (IDS-SR30).

Results

The two groups had similar baseline demographic data, psychiatric and treatment histories, and degrees of treatment resistance, except that more TAU participants had at least 10 prior major depressive episodes, and the VNS+TAU group had more electroconvulsive therapy before study entry. Vagus nerve stimulation plus treatment as usual was associated with greater improvement per month in IDS-SR30 than TAU across 12 months (p < .001). Response rates according to the 24-item Hamilton Rating Scale for Depression (last observation carried forward) at 12 months were 27% for VNS+TAU and 13% for TAU (p < .011). Both groups received similar TAU (drugs and electroconvulsive therapy) during follow-up.

Conclusions

This comparison of two similar but nonrandomized TRD groups showed that VNS+TAU was associated with a greater antidepressant benefit over 12 months.

Section snippets

Methods and Materials

Table 1 lists similarities and differences between the VNS+TAU and TAU studies. Treatment resistance for both the TAU and VNS+TAU studies was defined for the current MDE with a modified Antidepressant Treatment History Form (ATHF) (Oquendo et al 1999, Prudic et al 1990, Prudic et al 1996, Sackeim 2001a, Sackeim et al 1990, Sackeim et al 2000).

The TAU group was studied at 13 sites, 12 of which had participated in the VNS+TAU study. An additional 9 sites participated only in the VNS+TAU study.

Results

Table 2 presents the clinical and demographic features of the two evaluable samples (VNS+TAU, n = 205; TAU, n = 124). The VNS+TAU evaluable 12-month sample (Rush et al 2005b) excluded 3 participants who did not meet continuation criteria, 4 who had no long-term assessments, and 21 sham-control participants whose new baseline HRSD24 score at stimulation initiation was below the cutoff of ≥18. The TAU evaluable sample excluded three participants who did not provide data after the baseline

Discussion

This study compared two nonrandomized but similar groups of treatment-resistant depressed outpatients who received VNS+TAU or TAU alone over 12 months of treatment. The two groups were comparable in terms of baseline features. The primary analysis found a significant between-group difference favoring VNS+TAU over TAU alone that grew over time. Results were positive with and without propensity adjustments.

In addition, multiple secondary analyses found clinically important differences between the

References (25)

  • M. Hamilton

    A rating scale for depression

    J Neurol Neurosurg Psychiatry

    (1960)
  • M. Hamilton

    Development of a rating scale for primary depressive illness

    Br J Soc Clin Psychol

    (1967)
  • Cited by (292)

    View all citing articles on Scopus
    View full text