Treatment for mood disorders (depression and bipolar disorder) usually includes talk therapy, medication and support from people who understand. Sometimes people do not respond to traditional treatments or need additional help managing symptoms. Today many researchers are focusing their attention on technology to develop new, more effective treatments. These treatments may help people who have trouble finding relief with medication.

Looking At Where We’ve Been To Understand Where We’re Going  
Scientists believe that depression and bipolar disorder are caused by an imbalance of brain chemicals, called neurotransmitters. Medications used to treat mood disorders work to change brain chemistry and correct this imbalance. 

In the 1930s, researchers discovered that applying a small amount of electrical current to the brain caused small seizures that changed brain chemistry. Over the years, much has been done to make this form of treatment, Electroconvulsive Therapy (ECT), milder and easier for patients to tolerate. ECT is used to treat about 100,000 patients with depression each year. It is very effective in treating severe depression. However, there can be side effects such as confusion and memory loss. The procedure must be performed in a hospital with general anesthesia. 

This concept of altering brain function and chemistry with external stimulation has led to the development of several new technologies, which are now being tested to determine their safety and effectiveness in treating depression. Most of the work has focused on treating depression or the depressive phase of bipolar disorder. 

Transcranial Magnetic Stimulation (TMS)  
One procedure under investigation is Transcranial Magnetic Stimulation (TMS). TMS was first developed in 1985 and has been studied for as a treatment for mental illness since 1995. In TMS therapy, a special electromagnet delivers short bursts of energy to stimulate nerve cells in the brain. Research studies have shown this treatment has the beneficial results of altering brain chemistry and relieving depression.  Studies have shown TMS to be as effective in relieving symptoms as antidepressant medication, and it is generally free of the side effects.

Early TMS devices delivered a magnetic pulse every three seconds and were used by neurologists to diagnose nerve damage. Advances in the technology have resulted in machines that are capable of delivering up to 50 pulses per second. This rapid-rate TMS (rTMS) is thought to be a more effective depression treatment.

TMS therapy can be performed in a physician’s office. It does not require surgery, hospitalization, or anesthesia. A small hand-held device placed against the scalp delivers short magnetic pulses that can be focused to a specific area of the brain. This may allow for more precise treatment than procedures such as ECT. TMS sessions generally take 30 minutes. Current research suggests effective treatment should be given five days per week for two to four weeks.

The side effects associated with TMS are mild and relatively infrequent. Some patients report a slight knocking or tapping sensation on the head. This may be a result of the tapping sound produced by the TMS device. Some patients report feeling slight muscle contractions on the scalp. Others experience a mild headache or lightheadedness, which usually goes away soon after the treatment session.

As with any medical procedure, there are some risks associated with TMS. The main risk is that the device could cause a seizure, though current treatment guidelines make this extremely rare.  No memory loss or difficulty in concentration has been reported in any research study to date.

Vagus Nerve Stimulation (VNS)  
The vagus nerve is one of the primary communication pathways from the major organs of the body to the brain. Vagus Nerve Stimulation (VNS Therapy) is delivered through a small pulse generator, similar to a pacemaker, which is implanted in the left chest area and connected to the vagus nerve in the left side of the neck. The pulse generator sends small pulses to the vagus nerve, and the vagus nerve then delivers these pulses directly to the brain.

Because the vagus nerve does not contain pain fibers, stimulation is typically painless. VNS Therapy targets specific areas of the brain that affect mood and other symptoms of depression. Vagus nerve stimulation also influences the activity of neurotransmitters, such as serotonin and norepinephrine.

The pulse generator is programmed by a doctor to deliver this mild electrical stimulation to the brain at regular intervals. A person with VNS therapy can also use a special magnet to temporarily stop stimulation during certain situations or activities if needed.

The Food and Drug Administration (FDA) has approved VNS Therapy for people 18 years of age or older who are experiencing chronic or recurrent treatment resistant depression (depression that has not responded adequately to multiple treatment attempts). The treatment has been shown to be equally effective in both unipolar depression and bipolar disorder. Studies are ongoing for the use of VNS Therapy in rapid cycling bipolar disorder.

Side effects with VNS Therapy are mild to moderate, occur only during stimulation, and typically become less noticeable over time. The most common side effects with VNS Therapy include temporary hoarseness or a slight change in voice tone, increased coughing, a feeling of shortness of breath during physical exertion, and a tickling in the throat. The dose can be adjusted to avoid or reduce any troublesome side effects in many cases.

VNS Therapy is not associated with sexual dysfunction or memory impairment. Incidence of weight gain and sleep disturbance is less than 2%. Electric and electronic equipment, such as microwave ovens and cellular phones, generally will not affect the pulse generator. Airport security systems should not affect the pulse generator either; however, patients should carry an ID card that is provided after the procedure.

People with VNS Therapy should not use short-wave diathermy, microwave diathermy, or therapeutic ultrasound diathermy. For clear imaging, patients may need to be specially positioned for mammography procedures because of the location of the pulse generator in the chest. Once the device is implanted, it can be difficult to remove it. Inform your HCP you have a VNS device before having any medical procedure, especially magnetic resonance imaging (MRI).

Studies have shown that VNS can have beneficial results, especially for individuals who have not found relief with other treatments. These studies have also shown that these beneficial results improve over time and are sustained long-term.

Magnetic Stimulation Therapy (MST)  
One of the newest procedures under investigation for the treatment of mood disorders is Magnetic Stimulation Therapy (MST). MST uses powerful magnetic fields to induce a seizure, similar to one produced through ECT. Research studies involving people have only recently begun. Researchers believe MST will be able to focus its treatment on specific areas of the brain. It is hoped that this treatment will not affect memory or concentration. However, because the procedure causes a seizure, general anesthesia is required.

A Promising Future  
Emerging technologies such as rTMS, VNS and MST offer hope to people who are coping with treatment challenges. Much research is underway, but it will take time for to completely understand their potential risks and benefits.  At this point, the future looks promising.

As with any treatment, different people will have different responses. All individuals are advised to work with their doctors in collaborative partnerships to find the treatments that work best for them.

For more information:

• Vagus Nerve Stimulation Therapy, 1-877-NOW-4 VNS (1-877-669-4867) www.vnstherapy.com

• Transcranial Magnetic Stimulation (877) RTMS-4U2 (786-7482) www.neuronetics.com

Production of this information made possible by an educational grant from Neuronetics.