The term "brain stimulation therapies" might induce images of a therapy that's meant to be cognitively stimulating, but no — the approach is more direct! Brain stimulation therapies, instead, stimulate the brain directly, with things like electrodes (on the scalp or in the brain) or magnets.
Some kinds of brain stimulation therapy can be used to treat depression. They aren't first-line options and will only be offered to suitable patients if other treatments, like antidepressants and talk therapy, failed to offer satisfactory results, and sometimes in cases of acute suicidal feelings.
1. Electroconvulsive therapy
Electroconvulsive therapy, previously referred to as "shock therapy", is the most common and most studied kind of brain stimulation therapy, as well as the one with the longest history. Though its past and the way in which it is often portrayed in the media may cause some fear, electroconvulsive therapy is now a pretty safe and effective treatment for treatment-resistant depression.
During ECT, four electrodes are placed on the scalp. Two of these deliver an electric current (a much smaller one than used in the past!), while the others monitor the patient. The electric current induces a seizure that can help "rewire" the brain. Don't worry, though — patients are given a muscle relaxant and the whole procedure is administered under general anesthesia. Patients will feel no pain and won't even remember the electroconvulsive therapy, which lasts around 40 seconds. Treatment sessions are generally carried out every few days, to make for a total of six to 12.
Permanent memory loss is no longer a common side effect of ECT, though patients can experience side effects such as dizziness, headaches, blood pressure changes, and nausea.
Research has shown extremely promising results for people with treatment-resistant depression, with more than half achieving remission.
2. Deep brain stimulation
Deep brain stimulation surgery is used quite often to help people with Parkinson's disease and other movement disorders find relief from their symptoms. During a surgery, electrodes are implanted into a particular region of the brain to deliver impulses. Wires are fed through to a generator, a bit like a pacemaker, that's embedded in the chest. A remote control can switch the device on or off and adjust the settings.
Deep brain stimulation is still considered an experimental treatment for depression, though it has been used for movement disorders for longer. Preliminary data show that around half of patients undergoing the treatment will experience significant relief or achieve remission from depression.
Because deep brain stimulation requires an operation, it carries potential risks such as infection and brain hemorrhage. The procedure is considered safe in the right candidates, however.
3. Vagus nerve stimulation
Vagus nerve stimulation is similar to deep brain stimulation in that a device implanted in the chest sends impulses, but in this case the vagus nerve is stimulated. Originally developed as a treatment for epilepsy, vagus nerve stimulation is now also used for treatment-resistant depression. While the effect it offers may be modest at first, research suggests that the effect is amplified over time.
4. Transcranial magnetic stimulation
In repetitive transcranial magnetic stimulation, magnetic pulses are delivered to specific regions of the brain, which in turn induces electrical activity in the selected area. The treatment was specifically designed for depressed patients who weren't benefiting from other treatments, and it has been shown to be effective in some patients. Benefits of transcranial magnetic stimulation are that it can target particular areas of the brain, and because the procedure is painless (though patients can experience a "tapping sensation), no anesthesia is necessary. It is associated with fewer side effects than electroconvulsive therapy, and a session lasts around half an hour.
5. Magnetic seizure therapy
Like transcranial magnetic stimulation, magnetic seizure therapy uses magnetic impulses. This therapy also has elements of electroconulsive therapy, however, since it's meant to induce a seizure. As with ECT, magnetic seizure therapy requires patients to be under general anesthesia and receive a muscle relaxant. Though magnetic seizure therapy is fairly new, research has shown that it can liberate up to four in 10 of those who try it from treatment-resistant major depression.
Brain stimulation therapies most certainly won't be the first thing your doctor or psychologist will suggest once you have been diagnosed with major depressive disorder. These treatments are reserved for cases of depression that have not responded to any other treatment, including different approaches to talk therapy and a variety of antidepressant medications.
They open up a whole new world of potential to those people who have tried "everything" and are still living with depression, however. While brain stimulation therapies will not help everyone who undergoes them achieve remission from depression, they do help a significant portion of people.
Electroconvulsive therapy is the most studied of all these treatments and the kind most likely to be recommended to you first, but your medical team will work with you to decide what treatment is right for you.