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VNS stands for vagus nerve stimulation. The vagus nerves are a pair of large nerves carrying much information from the body, up through the neck, to appropriate areas of the brain. In VNS Therapy, a device similar to a pacemaker is placed in the chest wall. It sends small electrical pulses via a wire up to the vagus nerve in the left side of the neck. Then the vagus nerve delivers these pulses directly to areas of the brain felt to be responsible in some ways for depression. The pacemaker turns itself on every few minutes to deliver a tiny electrical pulse that is not painful, nor harmful to the patient. Repeatedly affecting these brain areas may slowly reverse depression symptoms over time.
Thomas L. Schwartz, MD
Assistant Professor Psychiatry and Behavioral Sciences
SUNY Upstate Medical University, Syracuse, NY
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The vagus nerve is one of the primary communication pathways from the major organs of the body to the brain. VNS Therapy is delivered by a pulse generator (a device like a pacemaker) via thin, flexible wires that apply mild electrical pulses to the vagus nerve in the left side of the neck. The vagus nerve delivers these pulses to specific areas of the brain involved in the regulation of emotions. Stimulating activity in the brain through VNS Therapy is thought to affect the production or activity of neurotransmitters (naturally occurring chemicals) that influence mood, sleep, and appetite.
Linda L. Carpenter, MD
Associate Professor, Department of Psychiatry and Human Behavior
Chief, Mood Disorders Program Butler Hospital, Brown University Medical School, Providence, RI
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At this point there is no known way to predict accurately who may benefit from any antidepressant treatment, including VNS Therapy. In a study of 235 people with chronic or recurrent treatment-resistant depression, 1 in 3 people who received VNS Therapy for a year experienced significant mood improvement, compared with 1 in 8 of those who received only other antidepressant treatments.
Robert H. Howland, MD
Associate Professor of Psychiatry
University of Pittsburgh School of Medicine
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VNS Therapy has been shown to work in people with bipolar depression. Of the 205 people evaluated in the major clinical study of VNS Therapy in depression, approximately 10% had been diagnosed with bipolar disorder. The rates of response (getting better) and remission (getting well) for people with bipolar disorder were similar to those for people with unipolar depression and for the group as a whole.1,2 Although research is ongoing, the safety and efficacy of VNS Therapy have not been established in people with rapid-cycling bipolar disorder. You and your psychiatrist will determine whether VNS Therapy may be a long-term treatment option for you.
Lauren Marangell, MD
Director, Mood Disorders Research, Department of Psychiatry
Baylor College of Medicine, Houston, TX
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There are many reasons why an antidepressant medication may not relieve symptoms of depression.
- First, the diagnosis may be incorrect. Some medical problems (like thyroid disorders) cause symptoms very similar to those of major depression
- Second, patients with major depression must take an adequate dose of a prescribed antidepressant medication and stay on it for an adequate time—often as long as 8 weeks—before benefits occur
- Some antidepressants or types of antidepressant drugs work better than others for some individuals with depression, so patients may experience relief from one drug even when adequate trials of other drugs didn't help
However, some people get the proper diagnosis, take antidepressant medications at high enough doses, and stay on them for months with minimal or no real relief from their depressive symptoms. In these people, the disorder is considered "treatment-resistant depression." Genetic factors, exposure to stressors at various points of childhood and adult life, and poorly understood biological processes may all contribute to a depression resistant to standard antidepressant medications.
Linda L. Carpenter, MD
Associate Professor, Department of Psychiatry and Human Behavior
Chief, Mood Disorders Program
Butler Hospital, Brown University Medical School, Providence, RI
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People have different response patterns to VNS Therapy. Some people respond very early and maintain their responses, while others respond much later. The design of the clinical study for FDA approval made it hard to relate the optimal dose to the response rates and to how long a person had had VNS Therapy. Clearly, while some people responded within 3 months of VNS Therapy stimulation, others first responded after 9 months or more.1,2 Because of this delayed response, it is essential to understand that this is a long-term treatment—very different from standard depression treatments like medications, which often take effect within weeks. In most people, the antidepressant effects of VNS Therapy are subtle at first. Family members often notice improvements (like more energy or greater motivation) before the patient does.
Charles R. Conway, MD
Assistant Professor of Psychiatry and Medical Director, Adult Inpatient Psychiatry Unit
Saint Louis University School of Medicine St. Louis, MO
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People who’ve been depressed for a long time can find it hard to believe that anything will ever work. But VNS Therapy is one treatment option shown to succeed where other treatments have failed, even after many years of depression.
The 205 people evaluated in the major clinical study of VNS Therapy had been depressed an average of 26 years over their lifetimes. Their current episode had lasted more than 4 years on average, with 2 out of 3 in episodes lasting 2 years or more, despite an average of 4 adequate treatments.1
After a year in this study, the people with long-standing depression had rates of response (getting better) and remission (getting well) similar to rates for the entire study group.2
About 3 out of 10 of the people with long-lasting depression improved significantly with VNS Therapy, and 1 in 7 were depression-free (compared to 1 in 6 for the VNS Therapy group as a whole).1, 2 As the chart shows, these rates of improvement were more than double those for a similar group of people who received standard antidepressant treatments but not VNS Therapy.
Karen Jacobs, DO
Department of Psychiatry and Psychology
Cleveland Clinic Foundation
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Major depression is frequently recurrent, so many people have more than one episode. It is understandable that you might feel frustrated to improve, only to have another depression episode a few months later. Certainly, you should adhere to your treatment plan and keep your mental health provider advised of any changes. Despite doing this, however, some people have additional episodes of depression. VNS Therapy is a good treatment option for these people.
VNS Therapy was specifically studied in patients who have had many recurrences. In a study of 205 people with treatment-resistant depression (TRD) observed for one year, approximately 144 had experienced three or more recurrences.1 After a year of VNS Therapy, 127 people with three or more recurrences of depression were just as likely to experience improvements from VNS Therapy as those with fewer recurrences. About 30% of people with three or more recurrences experienced significant mood improvements.2 This compared with response rates no higher than 16% for a comparison group of 73 people who received antidepressant treatment without VNS Therapy.2
Among the 127 observed people with three or more recurrences of depression, 18% experienced remission at one year—they became depression free. Again, this was similar to the rate for people with fewer recurrences.2 The remission rates for a comparison group of 73 people with three or more recurrences of depression who received antidepressant treatment without VNS Therapy were no higher than 10%.2
Research suggests that most people who improved on VNS Therapy maintained the improvement long-term. Up to 70% of the people with TRD who showed substantial clinical benefit within 3 or 12 months after starting VNS Therapy maintained the improvement at 2 years.3
Howard Houghton, MD
Assistant Professor of Clinical Psychiatry
University of Missouri-Columbia
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There is no one dose setting that works for everybody.1 Some people may see improvements at lower doses while other people may experience improvements at higher doses. Most people start with a current setting of 0.25 mA (milliamperes). After the person adjusts to 0.25 mA, the doctor increases the dose by another 0.25 mA every 2–3 weeks over the next 6–8 weeks or so. Increasing the current by 0.25 mA at a time allows the psychiatrist to achieve the most appropriate dose for each person while minimizing possible side effects.
In the clinical trials of VNS Therapy in TRD, the median value at 1 year was 1.0 mA for output current. The median value for how long the pulse lasted was 30 seconds. The median time between pulses was 5 minutes. 1
After a person reaches either the maximum tolerated dose or desired level of improvement, no further changes may be necessary. The psychiatrist then monitors the person’s progress with VNS Therapy over the next several months and changes the dosage depending on his or her outcome.
Darin Dougherty, MD
Assistant Professor of Psychiatry Massachusetts General Hospital Boston, MA
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VNS Therapy is added to your current medications. It is not a replacement for them. Some people in the clinical trials were able to reduce their medications over time. You and your psychiatrist will determine your ongoing treatment regimen. It is important to always follow your psychiatrist’s recommendations about your medications.
Robert H. Howland, MD
Associate Professor of Psychiatry
University of Pittsburgh School of Medicine
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VNS Therapy is different from ECT in several ways.
- Mode of action. VNS Therapy works differently from ECT. ECT affects large parts of the brain. Through the vagus nerve, VNS Therapy affects specific sites in the brain—sites associated with the symptoms of depression. And unlike ECT, VNS Therapy does not cause a seizure.
- Time frame. ECT works quickly1, but often the effects wear off after a while2. The benefits of VNS Therapy improve over time and are sustained long term. 3
- Side effects. VNS Therapy has a completely different safety profile from ECT, with few memory problems. 3
David L. Dunner, MD
Director, Center for Anxiety and Depression, Mercer Island, Washington
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Yes, VNS Therapy is effective in people who have had electroconvulsive therapy (ECT). And people who have VNS Therapy can receive ECT. VNS Therapy has been shown to succeed in people who have had ECT.1 Of the patients in clinical studies of VNS Therapy, about a third had had ECT during their current depression. Almost half had received it at some time in their lives.2-4 People who had received ECT were just as likely to experience improvement over time as those who had not.1 VNS Therapy patients can receive ECT if they need it. The only special requirement is that the VNS Therapy pulse generator must be turned off during ECT.
David L. Dunner, MD
Director, Center for Anxiety and Depression, Mercer Island, Washington
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In my experience, the number one side effect of VNS Therapy is voice change, usually mild hoarseness every several minutes when the device turns on. During these 30-second on-periods, the left half of the voice box may not work well due to the small electrical pulses going up the vagus nerve. This side effect usually diminishes over the first year of treatment, though it continues in a minority of patients. The patient can turn the pacemaker off temporarily, for example if he or she has a job interview or an important phone call. Other side effects may include cough, shortness of breath, difficulty swallowing, prickling in the skin, and neck pain. This device is unique in that there are no major side effects affecting the whole body like dizziness or sexual problems. Because the device is always working, you cannot forget to take it, unlike missed doses of antidepressant pills. VNS Therapy also does not interact with other antidepressants or other medications.
Thomas L. Schwartz, MD
Assistant Professor, Psychiatry and Behavioral Sciences
SUNY Upstate Medical University, Syracuse, NY
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VNS Therapy is usually turned on about 2 weeks after the implantation procedure. Then the dose is typically increased once a week by a very small amount (0.25 milliamperes), as tolerated. Although we don’t yet know what the “best” dose is, 1.25 to 1.50 milliamperes is the suggested target dose, so it takes 4 or 5 dosage adjustments to reach the target. Research is still ongoing to determine the optimal dose of stimulation. In the clinical studies, the dosing used was 30 seconds of stimulation delivered every 5 minutes. Once the dose is adjusted, stimulation is regular and automatic, and typically unnoticeable.
Charles R. Conway, MD
Assistant Professor of Psychiatry and Medical Director, Adult Inpatient Psychiatry Unit
Saint Louis University School of Medicine St. Louis, MO
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Each person’s experience is different. Some people experience meaningful changes within the first few weeks of treatment, while other patients may not experience significant benefit for 6 or even 12 months, and it may be very gradual. It is very important to keep your scheduled appointments with your psychiatrist and follow his or her instructions. In the clinical study of VNS Therapy in depression, many people experienced meaningful benefits in their everyday life. When measured after 9 months of VNS Therapy, improvements were seen in1:
- Vitality—increased energy
- Social functioning—increased social interaction with family and/or friends
- Emotional well-being—better function at work and in daily activities
- Mental health—more positive feelings
Often, family and friends may notice improvements even before you do. The VNS Therapy Web site (Evaluating Your Progress ) includes journal pages that can help you and your psychiatrist keep a record of your experience over time. Start by filling one out for a baseline, and then complete another page every few months.
Scott Aaronson, MD
Director of Clinical Research, Programs Sheppard Pratt Health System, Baltimore, MD
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After the VNS Therapy implant procedure, each patient receives a VNS Therapy Patient Essentials Kit containing a magnet. You can use the magnet to stop stimulation during certain situations or activities when even mild side effects might be inconvenient. For example, if you experience changes in voice tone during stimulation, you may want to temporarily stop stimulation if you plan to sing or speak in public. You can hold or place the magnet over the pulse generator during this activity. Or you may stop stimulation if it becomes uncomfortable.
David L. Dunner, MD
Director, Center for Anxiety and Depression, Mercer Island, Washington
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According to reports, the battery life with the current VNS Therapy pulse generator ranges from 3 to 8 years.1* Most of this experience comes from
people receiving VNS Therapy for epilepsy, but people with TRD report similar battery life. The battery life is highly dependent on device settings. Because a person’s VNS Therapy settings may change over time, the battery should be tested regularly, especially when the dosage is adjusted. The testing procedure enables the physician to
estimate how much life is left in the battery. It also provides a special signal to indicate when it’s time to evaluate the battery for replacement. Replacing the battery involves changing the pulse
generator that contains the battery. This is a minor outpatient surgical procedure. Typically, the surgeon does not replace the lead, but rather connects it to the new device. Sometimes it takes several dosing sessions to reestablish the stimulation settings used before the generator replacement.
As always, you should tell your physician about
any changes (up or down) in your mood and
discuss any stimulation-related side effects during
your office visits.
Pamela Sullivan, MD
Morgantown, WV
*For the full range of settings in relationship to battery life, see the Physician’s Manual or ask your psychiatrist.
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The battery life depends on device setting; some settings use more of the battery than others. The range of battery life with the current model (102) is 3–8 years.* A minor surgical procedure is scheduled to replace the battery, which replaces the generator. Typically, the old lead is plugged into the new device.
Lauren Marangell, MD
Director, Mood Disorders Research, Department of Psychiatry
Baylor College of Medicine, Houston, TX
*For the full range of settings in relationship to battery life, see the Physician’s Manual or ask your psychiatrist.
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“Will my insurance pay for VNS Therapy?” Many people ask this question. And in a number of cases, after a wait that may seem long, the answer is yes. The insurance process usually begins when a psychiatrist prescribes VNS Therapy, fills out a VNS Therapy Insurance Verification Form, and faxes it to the VNS Therapy Reimbursement Department at Cyberonics at 1-888-577-7205. In response, a Cyberonics insurance specialist will verify your benefits and send your doctor this information. Insurance companies usually require a letter of medical necessity—a letter from your psychiatrist describing your treatment history and explaining why you need VNS Therapy.
Since VNS Therapy was approved for treatment-resistant depression fairly recently, most insurance companies have not yet established coverage policies. However, if your insurance company denies coverage, Cyberonics can help.
- Your psychiatrist and the Cyberonics nurse case manager can help appeal the decision
- Together, they can provide the appeals department of your insurance company with additional information, such as more medical
records documenting the severity of your depression
- You may participate in the appeal by writing a letter or making a phone call to your insurance company
John P. O’Reardon, MD
Department of Psychiatry
University of Pennsylvania Health System
Philadelphia, PA
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Weight gain is a commonly reported side effect of
other antidepressant treatments. The 12-month study of VNS Therapy had weight data for 172 patients. Of these, 12% gained more than 7% of their baseline body weight, and 13% lost more than 7% of baseline body weight.1 Fewer than 2% of people in the clinical study reported weight gain.2
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Researchers are conducting studies to better understand the impact of VNS Therapy on anxiety, but so far, VNS Therapy is not approved for the treatment of anxiety. VNS Therapy rarely increases anxiety. Less than 5% of people in the yearlong study of VNS Therapy reported anxiety as a side effect.1
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In many cases, after what may seem like a long wait, the answer is yes. Since VNS Therapy was approved
for TRD fairly recently, most insurance companies have not yet established their coverage policies. Even
though Medicare recently announced a noncoverage position on VNS Therapy in TRD, case-by-case approvals have been obtained from more than 300 different payers.
You may have to go through several appeals to gain
coverage for VNS Therapy in TRD, and the process and the number of steps vary from state to state and
plan to plan. In addition, if you have a self-funded employee benefit plan and your health plan denies coverage, your employer can help you gain access. A
Cyberonics nurse case manager can help you and your psychiatrist determine if your insurance covers
VNS Therapy by verifying your benefits and determining the best way to pursue approval.
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The opinions expressed above are those of Drs. Aaronson, Carpenter, Conway, Dunner, Howland, Marangell and Schwartz and not necessarily those of Cyberonics, Inc. Cyberonics, Inc supports, in part, research for these doctors.
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