Dr Shock MD PhD

Research with patients is challenging and can be very rewarding and I mean not only for the researcher. To my opinion research ads value to patient care. Usually patients participating in research are better cared for, their treatment is more according to well documented and evaluated protocols. Monitoring makes wait and see impossible.

Results from these patient centered trials benefits patient care at the short and long term. If a treatment center publishes their results these results are usually implemented in their treatment protocols.

There is also a downside to this. Trials usually also means a lot of testing and blood samples to be drawn. I think these disadvantages out ways the benefits in patient care. One restriction is that study design should be good enough to make the results worthwhile. I hate it when authors excuse the lack of a control group or placebo group as can be read in a recent post about Vagus Nerve Stimulation research

The authors mention the argument sometimes used that it is unethical to use a controlled design with a sham condition. We are talking about patients treated with 3-7 different antidepressants and/or ECT. Mostly ill for years. I think it unethical to conduct another uncontrolled trial which will help our knowledge about the efficacy of VNS no further. Besides implanting a VNS is not peanuts nor going to a protocol of up to 1 year.

When preparing a lecture this dilemma about study design came to my mind. I have never seen a sample used for so many publications in high ranking medical journals than the patients taking part in a Vagus Nerve Stimulation research.

The research and follow up in 222 patients was used for several publications. The first publication was a terrific placebo controlled comparison of VNS with placebo. There was no significant difference between both groups. After that the patient sample was used for a follow-up of 12 months in total. Data from this sample is used in at least 3 other studies but all open and uncontrolled. Adding nothing or little to our knowledge for the use of VNS in depressed patients.

What do you think?


See also on this blog: VNS for depression an update

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What follows are citations for some of the larger published studies looking at VNS. Patients and psychiatrists will often be involved in applying for funding for further assessment/ treatment, and it is helpful to be able to state what the evidence is. All of these papers should either be available through the NHS e-library, or through any NHS/ hospital library.

An excellent overview of VNS studies with summaries of each of the study.

Thanks Therapeutic Neuromodulation

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Vagus Nerve Stimulation or VNS is hampered by insufficient research. After one disappointing publication of the results of a sham controlled multi site double-blind trial in a large sample no scientific important trials are conducted. This one trial did not demonstrate superiority of active VNS treatment over sham treatments after 3 months.

Since then (2005) another trial was conducted in Europe; an open uncontrolled multi-centre study. This trial used the same protocol as the first open, unblinded four centre pilot study of 60 patients in the US.

The authors mention the argument sometimes used that it is unethical to use a controlled design with a sham condition. We are talking about patients treated with 3-7 different antidepressants and/or ECT. Mostly ill for years. I think it unethical to conduct another uncontrolled trial which will help our knowledge about the efficacy of VNS no further. Besides implanting a VNS is not peanuts nor going to a protocol of up to 1 year.


Anyway, this open study also finds that the efficacy of VNS increases over time. The follow-up in this study is up to 12 months. Again efficacy is hard to interpret since it open labeled uncontrolled design.

VNS

VNS received FDA approval in July 2005 for adjunctive, long-term use in chronic or recurrent major depression in adult patients with an inadequate response to at least four antidepressant treatments. You could say it is an option after other treatments for depression has failed

Website with a lot of information on VNS: VNSDepression.com

Related post on this blog:
5 blogposts on Vagus Nerve Stimulation (Round Up)

Article discussed:
Psychol Med. 2008 Jan 4;:1-11 [Epub ahead of print]

Vagus nerve stimulation for depression: efficacy and safety in a European study.

Schlaepfer TE, Frick C, Zobel A, Maier W, Heuser I, Bajbouj M, O'Keane V,
Corcoran C, Adolfsson R, Trimble M, Rau H, Hoff HJ, Padberg F, Müller-Siecheneder
F, Audenaert K, Van den Abbeele D, Matthews K, Christmas D, Stanga Z, Hasdemir M.

Departments of Psychiatry and Mental Health, The Johns Hopkins University,
Baltimore, MD, USA.

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