Electroconvulsive Therapy

First developed in 1938, electroconvulsive therapy (ECT) for years had a poor reputation with many negative depictions in popular culture. However, the procedure has improved significantly since its initial use and is safe and effective. People who undergo ECT do not feel any pain or discomfort during the procedure.

ECT is usually considered only after a patient's illness has not improved after other treatment options, such as antidepressant medication or psychotherapy, are tried. It is most often used to treat severe, treatment-resistant depression, but occasionally it is used to treat other mental disorders, such as bipolar disorder or schizophrenia. It also may be used in life-threatening circumstances, such as when a patient is unable to move or respond to the outside world (e.g., catatonia), is suicidal, or is malnourished as a result of severe depression. One study, the Consortium for Research in ECT study, found an 86 percent remission rate for those with severe major depression. (1) The same study found it to be effective in reducing chances of relapse when the patients underwent follow-up treatments. (2)

Vagus Nerve Stimulation

Vagus nerve stimulation (VNS) works through a device implanted under the skin that sends electrical pulses through the left vagus nerve, half of a prominent pair of nerves that run from the brainstem through the neck and down to each side of the chest and abdomen. The vagus nerves carry messages from the brain to the body's major organs, like the heart, lungs and intestines, and to areas of the brain that control mood, sleep, and other functions.

VNS was originally developed as a treatment for epilepsy. However, it became evident that it also had effects on mood, especially depressive symptoms. Using brain scans, scientists found that the device affected areas of the brain that are also involved in mood regulation. The pulses also appeared to alter certain neurotransmitters (brain chemicals) associated with mood, including serotonin, norepinephrine, GABA and glutamate. (5)

In 2005, the U.S. Food and Drug Administration (FDA) approved VNS for use in treating major depression in certain circumstances—if the illness has lasted two years or more, if it is severe or recurrent, and if the depression has not eased after trying at least four other treatments. Despite FDA approval, VNS remains a controversial treatment for depression because results of studies testing its effectiveness in treating major depression have been mixed.

How does it work?

A device called a pulse generator, about the size of a stopwatch, is surgically implanted in the upper left side of the chest. Connected to the pulse generator is a lead wire, which is guided under the skin up to the neck where it is attached to the left-side vagus nerve.

Typically, electrical pulses that last about 30 seconds are sent about every five minutes from the generator to the vagus nerve. The duration and frequency of the pulses may vary depending on how the generator is programmed. The vagus nerve, in turn, delivers those signals to the brain. The pulse generator, which operates continuously, is powered by a battery that lasts around 10 years, after which it must be replaced. Normally, a person does not feel any sensation in the body as the device works, but it may cause coughing or the voice may become hoarse while the nerve is being stimulated.

The device also can be temporarily deactivated by placing a magnet over the chest where the pulse generator is implanted. A person may want to deactivate it if side effects become intolerable or before engaging in strenuous activity or exercise because it may interfere with breathing. The device reactivates when the magnet is removed.

What are the side effects?

VNS is not without risk. There may be complications, such as infection, from the implant surgery, or the device may come loose, move around or malfunction, which may require additional surgery to correct. Long-term side effects are unknown.

Other potential side effects include:

• Voice changes or hoarseness

• Cough or sore throat

• Neck pain

• Discomfort or tingling in the area where the device is implanted

• Breathing problems, especially during exercise

• Difficulty swallowing

Repetitive Transcranial Magnetic Stimulation [rTMS]

Repetitive transcranial magnetic stimulation (rTMS) uses a magnet instead of an electrical current to activate the brain. First developed in 1985, rTMS has been studied as a possible treatment for depression, psychosis and other disorders since the mid-1990's.

Clinical trials studying the effectiveness of rTMS reveal mixed results. When compared to a placebo or inactive (sham) treatment, some studies have found that rTMS is more effective in treating patients with major depression. (6) But other studies have found no difference in response compared to inactive treatment. (7)

In October 2008, rTMS was approved for use by the FDA as a treatment for major depression for patients who have not responded to at least one antidepressant medication. It is also used in countries such as in Canada and Israel as a treatment for depression for patients who have not responded to medications and who might otherwise be considered for ECT.

How does it work?

Unlike ECT, in which electrical stimulation is more generalized, rTMS can be targeted to a specific site in the brain. Scientists believe that focusing on a specific spot in the brain reduces the chance for the type of side effects that are associated with ECT. But opinions vary as to what spot is best.

A typical rTMS session lasts 30 to 60 minutes and does not require anesthesia. An electromagnetic coil is held against the forehead near an area of the brain that is thought to be involved in mood regulation. Then, short, electromagnetic pulses are administered through the coil. The magnetic pulse easily passes through the skull and causes small electrical currents that stimulate nerve cells in the targeted brain region. And because this type of pulse generally does not reach further than two inches into the brain, scientists can select which parts of the brain will be affected and which will not be. The magnetic field is about the same strength as that of a magnetic resonance imaging (MRI) scan. Generally, the person will feel a slight knocking or tapping on the head as the pulses are administered.

Not all scientists agree on the best way to position the magnet on the patient's head or give the electromagnetic pulses. They also do not yet know if rTMS works best when given as a single treatment or combined with medication. More research, including a large NIMH-funded trial, is underway to determine the safest and most effective use of rTMS.

What are the side effects?

Sometimes a person may have discomfort at the site on the head where the magnet is placed. The muscles of the scalp, jaw or face may contract or tingle during the procedure. Mild headache or brief lightheadedness may result. It is also possible that the procedure could cause a seizure, although documented incidences of this are uncommon. A recent, large-scale study on the safety of rTMS found that most side effects, such as headaches or scalp discomfort, were mild or moderate and no seizures occurred. (8) Because the treatment is new, however, long-term side effects are unknown.

Magnetic Seizure Therapy

Magnetic seizure therapy (MST) borrows certain aspects from both ECT and rTMS. Like rTMS, it uses a magnetic pulse instead of electricity to stimulate a precise target in the brain. However, unlike rTMS, MST aims to induce a seizure like ECT. So the pulse is given at a higher frequency than that used in rTMS. Therefore, like ECT, the patient must be anesthetized and given a muscle relaxant to prevent movement. The goal of MST is to retain the effectiveness of ECT while reducing the cognitive side effects usually associated with it.

MST is currently in the early stages of testing, but initial results are promising. Studies on both animals and humans have found that MST produces fewer memory side effects, shorter seizures, and allows for a shorter recovery time than ECT. (9, 10) However, its effect on treatment-resistant depression is not yet established. Studies are underway to determine its antidepressant effects.

Deep Brain Stimulation

Deep brain stimulation (DBS) was first developed as a treatment for Parkinson's disease to reduce tremor, stiffness, walking problems and uncontrollable movements. In DBS, a pair of electrodes is implanted in the brain and controlled by a generator that is implanted in the chest. Stimulation is continuous, and its frequency and level is customized to the individual.

DBS has only recently been studied as a treatment for depression or obsessive compulsive disorder (OCD). Currently, it is available on an experimental basis only. So far, very little research has been conducted to test DBS for depression treatment, but the few studies that have been conducted show that the treatment may be promising. One small trial involving people with severe, treatment-resistant depression found that four out of six participants showed marked improvement in their symptoms either immediately after the procedure, or soon after. (11) Another study involving 10 people with OCD found continued improvement among the majority three years after the surgery. (12)

How does it work?

DBS requires brain surgery. The head is shaved and then attached with screws to a sturdy frame that prevents the head from moving during the surgery. Scans of the head and brain using MRI are taken. The surgeon uses these images as guides during the surgery. Patients are awake during the procedure to provide the surgeon with feedback, but they feel no pain because the head is numbed with a local anesthetic.

Once ready for surgery, two holes are drilled into the head. From there, the surgeon threads a slender tube down into the brain to place electrodes on each side of a specific part of the brain. In the case of depression, the part of the brain targeted is called Area 25. This area has been found to be overactive in depression and other mood disorders. (11) In the case of OCD, the electrodes are placed in a different part of the brain believed to be associated with the disorder.

After the electrodes are implanted and the patient provides feedback about the placement of the electrodes, the patient is put under general anesthesia. The electrodes are then attached to wires that are run inside the body from the head down to the chest, where a pair of battery-operated generators are implanted. From here, electrical pulses are continuously delivered over the wires to the electrodes in the brain. Although it is unclear exactly how the device works to reduce depression or OCD, scientists believe that the pulses help to "reset" the area of the brain that is malfunctioning so that it works normally again.

What are the side effects?

DBS carries risks associated with any type of brain surgery. For example, the procedure may lead to:

• Bleeding in the brain or stroke

• Infection

• Disorientation or confusion

• Unwanted mood changes

• Movement disorders

• Lightheadedness

• Trouble sleeping

Because the procedure is still experimental, other side effects that are not yet identified may be possible. Long-term benefits and side effects are unknown.

Resources

Brain Stimulation 

Brain Stimulation aims to be the premier journal for publication of original research in the field of neuromodulation. The journal includes: a) original articles (up to 4,000 words); b) brief reports (up to 1,000 words); c) invited and original reviews; d) technology and methodological perspectives (reviews of new devices, description of new methods, etc.); and e) letters to the Editor. Special issues of the journal will be considered based on scientific merit.

Mayo Clinic - Deep Brain Stimulation

Overview - Deep brain stimulation involves implanting electrodes within certain areas of your brain. These electrodes produce electrical impulses that regulate abnormal impulses. Or the electrical impulses can affect certain cells and chemicals within the brain. The amount of stimulation in deep brain stimulation is controlled by a pacemaker-like device placed under the skin in your upper chest. A wire that travels under your skin connects this device to the electrodes in your brain.

Psychology Today - Brain Stimulation Therapy

Brain stimulation therapy is a procedure that uses electrodes or magnets in the brain or on the scalp to treat some serious mental disorders that do not respond successfully to commonly used psychotherapies and medications. There are several types of brain stimulation therapies, including electroconvulsive therapy (ECT), vagus nerve stimulation (VNS), repetitive transcranial magnetic stimulation (rTMS), magnetic seizure therapy (MST), and deep brain stimulation (DBS).

Of these, ECT is the oldest and most widely used procedure. The other brain stimulation therapies are interventions that are sometimes used to treat other medical conditions, or they are newly developed therapies, but more research needs to be done to determine their effectiveness and safety in treating mental disorders.