The first-line treatments for major depressive disorder (MDD) are antidepressant drugs and talk therapy. But for some people, these methods do not successfully control symptoms. These people have what is called treatment-resistant depression.1-3
People with treatment-resistant depression may benefit from other options, like brain stimulation therapy. Research into brain stimulation therapy and its benefits is ongoing. But doctors are already using several types of it to help people with MDD.2,3
Electroconvulsive therapy (ECT)
Electroconvulsive therapy (ECT) involves giving small electrical currents to the brain. These pulses of electricity cause the body to have a seizure. When the body seizes, blood flow and levels of neurotransmitters in the brain immediately increase.2-5
Neurotransmitters are chemicals the brain uses to send signals about mood, behavior, and more. Experts think an imbalance of neurotransmitters like serotonin plays a role in depression symptoms.2-5
ECT is done under general anesthesia. This means the person is completely put to sleep. ECT is done in a supervised, controlled setting by a trained doctor. It may be helpful for people who are pregnant, older adults, and people who otherwise cannot take antidepressant drugs. In addition to depression, ECT is used to treat certain symptoms of dementia, schizophrenia, and bipolar disorder.5
Often, ECT is given several times a week for a few weeks at a time. The treatment itself only lasts a few minutes. Some of the most common side effects of ECT are nausea, headache, muscle aches, or jaw pain. Blood pressure and heart rate may increase, too. After treatment, it is possible to have confusion or memory loss. These can last for several weeks or months after treatment is over.5
Magnetic seizure therapy (MST)
Like ECT, magnetic seizure therapy (MST) is a type of brain stimulation that causes a person to have a seizure. But instead of using electricity, it uses magnetic waves. In both ECT and MST, seizures often last less than a minute.6,7
The benefits of MST compared to ECT for treatment-resistant depression is an area of active research. How effective each option is may depend on how strong the electrical or magnetic waves used are and what areas of the brain they target.6,7
Some experts believe that MST affects memory less than ECT does. They also think the period of confusion after a seizure (called the postictal period) may be shorter after MST. These benefits are being studied. MST may also be helpful for people with psychosis (like those with schizophrenia) and people with obsessive-compulsive disorder (OCD).6,7
The most common side effects of MST include nausea, vomiting, muscle aches, headache, and dizziness. MST also requires a person to be put to sleep with general anesthesia. Anesthesia has its own risks and may not be safe for everyone.6
Repetitive transcranial magnetic stimulation (rTMS)
Like MST, transcranial magnetic stimulation (TMS) uses magnetic waves. But the waves do not cause a seizure. TMS is approved by the US Food and Drug Administration (FDA). It is non-invasive, meaning you do not need to have surgery or get anesthesia to have TMS.8-10
In TMS, an electrical device called an electric coil is placed against the scalp. This device delivers magnetic waves to certain areas of the brain. Experts do not understand the exact way TMS works. They think it activates certain areas of the brain that play a role in mood. These areas may be less active in people with depression.8,9
TMS also may be helpful for people with migraine headaches, those trying to quit smoking, and people with OCD.8,9
When used for depression, TMS involves giving repeated magnetic pulses to the brain. This is called repetitive TMS (rTMS). The most common side effects of rTMS are headache, scalp pain, dizziness, and tingling or twitching of the muscles in the face.8,9
rTMS is performed in a doctor’s office rather than a hospital. People undergoing rTMS may have a treatment session 5 days per week for 4 to 6 weeks at a time. Each session is usually less than 20 minutes. Many people can drive themselves home afterward.8,9
Deep brain stimulation (DBS)
Like TMS, deep brain stimulation (DBS) is a treatment option that stimulates certain areas of the brain. But it is invasive, requiring anesthesia and brain surgery. DBS uses electrical currents like ECT, but it does not cause seizures. Instead of electrodes placed on the scalp, DBS uses electrodes that are implanted into the brain to deliver the currents.11,12
A pacemaker-like device is also implanted into the chest. A wire placed under the skin connects the chest device to the electrodes in the brain. A special remote controls the level of stimulation in the brain. Some people have constant stimulation. Others are able to turn the electrodes off and on. You and your doctor will work together to find the right settings for you. This can take weeks or months.11,12
Some side effects of DBS are related to the surgery to place the electrodes, pacemaker device, and wire. These side effects include brain bleeding, stroke, infection, seizures, heart issues, confusion, nausea, pain, and issues breathing.11
Side effects of the brain stimulation itself include tingling or numbness, tightened muscles in the face or arm, dizziness, and issues with speech, balance, and vision. DBS may also worsen mood changes in some people.11
DBS can be used to treat several different health issues. These include Parkinson’s disease, chronic seizures (epilepsy), OCD, Huntington’s disease, certain types of headaches, and chronic pain.11,13
Vagus nerve stimulation (VNS)
Vagus nerve stimulation (VNS) also uses an implantable device to send signals to the brain. But in VNS, the device targets the vagus nerve instead of the brain. The vagus nerve runs through the chest and neck. When it is stimulated, it can affect the brain.14,15
Surgery is necessary to implant the device. This surgery requires general anesthesia. But it involves only small incisions into the neck and chest rather than brain surgery. After the surgery, people often can go home the same day.14
There are vagus nerves on both the right and left side of the body. When VNS is used for depression, the device is usually placed on the left side. This is because the right vagus nerve may impact the heart more than the brain. How much stimulation your device provides and how often will be adjusted by your doctor. It can take weeks to find the right settings for you.14,15
In addition to depression, VNS may be helpful for those with epilepsy or stroke. But, like all procedures, there are risks to having a VNS device implanted. These include pain, infection, or headaches. Because the vagus nerve runs through the neck, it is also possible to have voice changes, cough, issues swallowing, trouble breathing, or throat pain when using the device.14