What Is Transcranial Magnetic Stimulation (TMS)?

TMS therapy, or transcranial magnetic stimulation, is a noninvasive (non-surgical) form of therapy that uses a series of short, magnetic pulses to stimulate nerve cells in your brain. TMS doesn't require anesthesia and is usually well-tolerated—sometimes even better than antidepressants.1

The most common goal of TMS therapy is to provide relief and help break the cycle of certain mental health conditions. It's often used for depression, but it might also help treat obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), chronic pain, and movement-related disorders like Parkinson's disease.1

Side effects are usually minimal, but certain people should avoid TMS—for example, people with metal head implants or epilepsy (seizure disorder).

How Does TMS Therapy Work?

With TMS therapy, short magnetic pulses are passed through a coil into your brain. This creates a magnetic field that repeatedly stimulates neurons (nerve cells). The magnetic pulses are usually directed at specific areas of your brain that are thought to affect your mood.234

For example, the left prefrontal cortex is an area that often shows abnormal electrical activity in people who have depression. The prefrontal cortex is considered the "personality center" of your brain. It helps you process information, regulate emotions and behaviors, plan, and make decisions.5

The motor cortex, which controls movement, is another brain area that might be targeted. Stimulating the motor cortex with TMS therapy might help treat movement-related disorders like Parkinson's disease.67

The way that TMS therapy works is not completely understood. Magnetic pulses might affect certain neurons in your brain, causing long-term inhibition and excitation. In other words, TMS therapy might help you control your responses and impulses.234

rTMS, dTMS, and DBS

There are two main types of TMS: repetitive transcranial magnetic stimulation (rTMS) and deep TMS (dTMS). Both techniques are non-invasive. The main difference is that they use different coils. The dTMS coil reaches deeper and larger brain areas.8

Deep brain stimulation (DBS) is an invasive technique that involves surgically implanting wires into the brain.9

Which Conditions Does TMS Therapy Treat?

Several conditions may benefit from TMS therapy. However, only three have been approved by the Food and Drug Administration (FDA): depression, OCD, and nicotine addiction.1011

Depression

The FDA indicates that people who have not responded to traditional treatments for major depressive disorder (MDD) like antidepressants and cognitive behavioral therapy (CBT) are good candidates for TMS therapy. This is partly due to the high success rate of TMS therapy for depression.12

Research shows that 50-55% of people who try TMS therapy respond to it and 30-35% are symptom-free after treatment.12 TMS therapy might be used in addition to other treatment options like psychotherapy (talk therapy).13

Obsessive-Compulsive Disorder (OCD)

Like depression, TMS might be recommended for people with obsessive-compulsive disorder (OCD) if other treatment options haven't been effective.14

OCD is a condition that causes unwanted and intrusive thoughts or images (obsessions) and repetitive behaviors and actions (compulsions). TMS therapy can reduce increased activity in the prefrontal cortex, a common feature of OCD.15

Nicotine Addiction

Healthcare providers might use TMS therapy to treat nicotine addiction when other strategies to quit smoking are unsuccessful. Researchers believe that targeting the prefrontal cortex reduces nicotine cravings, especially if dopamine is released.16

Dopamine is a neurotransmitter that plays a role in your sense of pleasure. It's released after a rewarding experience—in this case, smoking—which helps you label that experience as positive.

Other Conditions

Therapists may suggest using TMS therapy to treat other conditions when more traditional treatments don't work. Here are some of the more common conditions that may be treated by TMS:

Generalized Anxiety Disorder (GAD): GAD is a mood disorder thought to affect the same area of the brain as depression. For this reason, healthcare providers may suggest TMS. Preliminary research also suggests that TMS may reduce activity in the prefrontal cortex, much like it does when treating depression.17

Post-Traumatic Stress Disorder (PTSD): PTSD and major depression often occur together, which suggests that TMS therapy might be useful for treating PTSD.1819 One study found that using TMS with cognitive processing therapy (CPT) reduced PTSD symptoms in some people for up to six months.20 CPT is a type of CBT that helps people process and shift beliefs around trauma.

Chronic pain syndrome (CPS): About 85% of people with chronic pain have also been diagnosed with severe depression.21 For this reason, researchers have been exploring the possibility that TMS may reduce chronic pain.22

Parkinson's disease: Stimulating the motor cortex may reduce motor symptoms of Parkinson's disease, such as freezing of gait (FOG)—suddenly being "stuck" and unable to walk forward.6 Stimulating the prefrontal cortex might help reduce depressive symptoms.7

What To Expect

TMS therapy is usually performed by a physician, psychiatrist. It typically takes place in a clinic or hospital setting. Here are some things to expect before, during, and after therapy.

Before TMS Therapy

After you decide on a provider for your TMS therapy, you will likely start with an initial consultation. The provider will explain the procedure, including costs, length of treatment, potential risks, and what you can expect. Most insurances cover TMS, though coverage might depend on your diagnosis.23

The provider will do several tests to determine if this type of treatment is right for you, including a psychiatric evaluation and lab tests.

On the day of your treatment, you will likely be asked to remove anything metal that could interfere with the magnets used, such as jewelry or clothing that has metal in it.1

During TMS Therapy

During rTMS therapy, you sit in a reclining chair with earplugs. An electromagnetic coil is placed on your scalp, near your forehead. Short magnetic pulses are directed into your brain focusing primarily on the targeted area. The person performing the treatment will determine the amount of magnetic energy needed because this varies from person to person.91

You can expect an rTMS treatment session to last about 40-60 minutes. Anesthesia is not necessary, so you will remain awake throughout the therapy. You'll typically have several TMS therapy sessions over several weeks. Your healthcare provider will determine the number of weekly sessions as well as the number of weeks treatment lasts.9

If you have dTMS, the therapy will involve a different device, including a helmet with a coil in it. Treatment time is 20-30 minutes. You'll likely have sessions five days a week for 4-6 weeks.24

After TMS Therapy

You can return to your normal activities after each therapy session. You may experience headaches or scalp pain, but this is usually minor and not anything to be concerned about. Talk to your healthcare provider about your symptoms if your pain or discomfort is significant.25

Side Effects of TMS Therapy

The side effects and risks associated with TMS therapy are minimal and are easily managed. Headaches are the most common side effect. You'll likely experience them during or right after therapy.25

Most headaches are like tension headaches. They occur because your scalp muscles contract when the magnetic field stimulates them. Scalp pain or discomfort can also occur—usually during the procedure—due to muscle contractions.25

Facial pain, dizziness, and lightheadedness are other possible side effects. There is a slight risk of hearing loss, but it can be prevented by using proper earplugs during the procedure. A TMS therapy-induced seizure is the most serious risk, but it's rare and only occurs in about 0.1% of cases.2526

Most adults can receive TMS therapy. However, some who are not eligible for this type of treatment because of the risks it poses to their health and well-being. People with the following conditions or implants should not have TMS therapy:123

Epilepsy

Pre-existing neurological disease

Cochlear (hearing) implants

Metallic or electronic implants

Metallic tattoos, permanent piercings, or metal fragments

Aneurysm clips or coils

Brain stents

How To Find a TMS Therapy Provider

TMS therapy is typically offered by psychiatrists who have completed specific TMS training. They usually perform TMS under the supervision of a medical doctor (MD) or doctor of osteopathic medicine (DO) trained in TMS.27 DOs receive the same amount of training as medical doctors, but they use a more holistic treatment approach.28

Finding a qualified TMS therapy provider can be somewhat of a challenge, especially since this type of treatment is relatively new. You can ask your healthcare provider or call your health insurance company for the contact information of psychiatrists in your area who accept your insurance. A good rule of thumb is to ask for at least three names and numbers. You can also clarify what your insurance will cover and what you will need to pay out of pocket.29

The Clinical TMS Society has a Find a TMS Clinic search tool. However, this tool only includes members who have agreed to make their contact information public. It also doesn't verify the credentials or qualifications of providers.30