Currently, case managers see three major treatments for major depressive disorders. These include anti-depressant medication, cognitive behavioral or interpersonal psychotherapy, and electro-convulsive therapy. Electro-convulsive therapy is usually reserved for treatment resistant episodes of depression or when a rapid response due to urgent clinical signs or symptoms is necessary.

Vagal nerve stimulation (VNS) is a new proposed procedure for treating resistant depression. In VNS, a therapy pulse generator and lead are surgically implanted and external programming is used to change the stimulation setting.

But is this treatment supported by research as a medical necessity? A review of existing literature gives us an answer.

In July 2005, the FDA approved VNS as an adjunctive long-term treatment for chronic or recurrent depression in patients 18 years of age or older experiencing a major depressive episode who have not had an adequate response to four or more adequate anti-depressant medications.

While VNS has had some review in the literature, it is important to note that most of these studies were sponsored by Cyberonics, the manufacturer of the VNS device.

Rush et al, published a randomized clinical trial to establish the efficacy of VNS. The trial had a 10 week component, where subjects were randomized, controlled and masked. There was a two week single blind recovery period and then 10 weeks of masked active or sham VNS. Medications were kept stable during the treatment. Results were scored from the Hamilton rating scale for depression. The primary outcome measures showed that the response rates were 15.2 percent for active treaters and 10 percent for the sham group in this study. Notably, the authors conclude that this study did not yield definitive evidence of short-term efficacy for adjunctive VNS in treating therapy resistant depression.

Sackheim et al, 2001, clinically studied VNS in cognition,. This study was to show whether VNS had an effect on cognitive performance in patients with treatment resistant depression. The study concluded that VNS stimulation in treatment resistant depression may result in enhanced neurocognitive functioning among patients who show clinical improvement. Controlled studies were recommended to rule out other contributing factors.

George et al, 2005, conducted a clinical trial to understand the effects of VNS on long-term outcomes in patients with major depressive disorders. This study showed that VNS plus treatment as usual, was associated with greater anti-depressant benefit over a 12 month period.

Still the safety and efficacy of VNS has not been established. There are no randomized controlled studies demonstrating efficacy for the patient. The non-randomized efficacy analysis is riddled with the potential for bias. The FDA statistical review repeatedly called Cyberonics analysis questionable, and concluded that it was not clear that efficacy had been established. The FDA Advisory Committee members agreed that a safety-benefit ratio could not be established with the data available. The FDA has raised questions about increased suicides, worsening depression, and sudden death, all of which deserve further investigation. The FDA issued a non-approvable letter to Cyberonics in August 2004, but, in a highly unusual reversal of position, the FDA issued an approvable letter in February 2005.

Case managers should be aware that there is no pertinent clinical data available from well-conducted randomized controlled or cohort trials in the prevailing peer-reviewed published medical literature adequately concluding that VNS therapy is safe and effective for the treatment of therapy resistant depression. Based on the current studies, case managers should deny claims for VNS treatment for depression to their health plan subscribers because this treatment has not been proven to be medically necessary.