Effects of 12 months of vagus nerve stimulation in treatment-resistant depression: a naturalistic study.
ABSTRACT The need for effective, long-term treatment for recurrent or chronic, treatment-resistant depression is well established.
This naturalistic follow-up describes outpatients with nonpsychotic major depressive (n = 185) or bipolar (I or II) disorder, depressed phase (n = 20) who initially received 10 weeks of active (n = 110) or sham vagus nerve stimulation (VNS) (n = 95). The initial active group received another 9 months, while the initial sham group received 12 months of VNS. Participants received antidepressant treatments and VNS, both of which could be adjusted.
The primary analysis (repeated measures linear regression) revealed a significant reduction in 24-item Hamilton Rating Scale for Depression (HRSD(24)) scores (average improvement, .45 points [SE = .05] per month (p < .001). At exit, HRSD(24) response rate was 27.2% (55/202); remission rate (HRSD(24) < or = 9) was 15.8% (32/202). Montgomery Asberg Depression Rating Scale (28.2% [57/202]) and Clinical Global Impression-Improvement (34.0% [68/200]) showed similar response rates. Voice alteration, dyspnea, and neck pain were the most frequently reported adverse events.
These 1-year open trial data found VNS to be well tolerated, suggesting a potential long-term, growing benefit in treatment-resistant depression, albeit in the context of changes in depression treatments. Comparative long-term data are needed to determine whether these benefits can be attributed to VNS.
Surgical Neurology International 01/2014; 5(Suppl 5):S211-31. DOI:10.4103/2152-7806.137936 · 1.18 Impact Factor
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ABSTRACT: Treatment resistant depression (TRD) is a global health concern affecting a large proportion of depressed patients who then require novel therapeutic options. One such treatment option that has received some attention in the past several years is vagal nerve stimulation (VNS). The present review briefly describes the relevance of this treatment in the light of other existing pharmacological and non-pharmacological options. It then summarizes clinical findings with respect to the efficacy of VNS. The anatomical rationale for its efficacy and other potential mechanisms of its antidepressant effects as compared to those employed by classical antidepressant drugs are discussed. VNS has been approved in some countries and has been used for patients with TRD for quite some time. A newer, fast-acting, non-invasive pharmacological option called ketamine is currently in the limelight with reference to TRD. This drug is currently in the investigational phase but shows promise. The clinical and preclinical findings related to ketamine have also been summarized and compared with those for VNS. The role of neurotrophin factors, specifically brain derived neurotrophic factor and its receptor, in the beneficial effects of both VNS and ketamine have been highlighted. It can be concluded that both these therapeutic modalities, while effective, need further research that can reveal specific targets for intervention by novel drugs and address concerns related to side-effects, especially those seen with ketamine.Clinical Psychopharmacology and Neuroscience 08/2014; 12(2):83-93. DOI:10.9758/cpn.2014.12.2.83This article is viewable in ResearchGate's enriched formatRG Format enables you to read in context with side-by-side figures, citations, and feedback from experts in your field.
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ABSTRACT: Background Depression is the most common psychiatric comorbidity in epilepsy patients. The lack of success with current pharmacological interventions for this patient population, highlights the importance of optimizing non-pharmacological neuromodulatory treatments such as vagus nerve stimulation (VNS). Studies on the antidepressant effect of VNS in epilepsy patients may be confounded by concurrent antiepileptic drug therapy. To date, studies in epilepsy models overcoming this problem are lacking. Objective We investigated whether VNS affects anhedonia, a key symptom of major depression, in the kainic acid rat model for temporal lobe epilepsy. Methods Anhedonia was assessed in kainic acid (KA) and saline (SAL) injected rats using the saccharin preference test (SPT). To exclude differences in taste perception, the quinine aversion test (QAT) was performed. Both groups were randomly subdivided in a VNS and a SHAM group, yielding 4 experimental arms: KA-VNS, KA-SHAM, SAL-VNS and SAL-SHAM. Both VNS groups received 2 weeks of VNS, while the SHAM groups were not stimulated. Thereafter, the SPT and QAT were repeated. Results Saccharin preference was significantly reduced in the KA compared to the SAL rats (p<0.05), without differences in quinine aversion. Two weeks of VNS significantly increased the saccharin preference in the KA-VNS group (p<0.05), while it had no effect on quinine aversion. No effects of VNS or SHAM were found in the other groups. Conclusion The KA rats displayed anhedonia which was significantly decreased by VNS, indicating that this neuromodulatory treatment could likewise diminish depressive symptoms in patients suffering from temporal lobe epilepsy and comorbid depression.Brain Stimulation 09/2014; 8(1). DOI:10.1016/j.brs.2014.09.013 · 5.43 Impact Factor