Transcranial magnetic stimulation (TMS), also referred to as repetitive TMS or rTMS, is a medication-free depression treatment. Approved by the FDA in 2008 for treatment-resistant depression, TMS therapy has helped thousands of patients find relief from depression symptoms when antidepressants couldn’t.
What is TMS (rTMS)?
TMS is a noninvasive treatment that uses brain stimulation to relieve symptoms of depression. More specifically, TMS uses magnetic pulses to stimulate neurons (brain cells) that are underactive. Transcranial magnetic stimulation is also referred to as rTMS (repetitive TMS) because treatment is administered using multiple, short, repetitive magnetic pulses. These pulses create a magnetic field that electrically stimulates neurons. The magnetic field produced by a TMS machine is similar to that of a magnetic resonance imaging (MRI) machine.
How Does TMS Interact With the Brain to Relieve Depressive Symptoms?
The brain functions through networks of neurons, called neuronal pathways, that transmit messages between other neurons and cells throughout the body. In addition to facilitating communication among neurons within each brain region, neuronal pathways also allow different regions of the brain to communicate with each other.
Traditionally, antidepressants have been prescribed to chemically stimulate neurons. But neurons can also be electrically stimulated. The magnetic field created by a TMS machine creates an electrical field that interacts with the electrical activity of neurons. TMS stimulates underactive neurons in specific areas of the dorsolateral prefrontal cortex of the brain (a brain region known for its role in mood regulation) to achieve numerous outcomes that help relieve depression symptoms.
TMS Stimulates Underactive Neurons to Release Neurotransmitters
Neurons communicate with each other by releasing special chemicals, called neurotransmitters. When neurons are underactive, they release fewer neurotransmitters, affecting normal communication between neurons. Research shows that people with depression have lower levels of certain neurotransmitters, including dopamine, norepinephrine, and serotonin. (1) When stimulated with TMS therapy, underactive neurons begin to release more neurotransmitters and repair damaged communication pathways.
TMS Increases Blood Flow and Oxygen Levels in the Brain
Earlier studies observed that certain parts of the brain in depressed patients have decreased blood flow and volume. (2) When an area of the brain is underactive, it uses less oxygen and requires less blood flow. Stimulating the brain with TMS increases blood flow and therefore oxygen to underactive areas of the brain. (3)
After a TMS Treatment Session, Neurons are Rearranging
Scientists have evidence that neurons show a preference or bias for certain pathways of communication. TMS interrupts these preferences to form new connections and therefore new neuronal pathways.
A recent study observed the behavior of neurons of the visual cortex (the visual cortex processes visual information) in the brains of cats before and after TMS. The cats were shown the same visual stimulus both before and after TMS, and scientists observed neuron activity in the cats while they were watching the visual stimuli. Researchers observed that after TMS, neurons responded in a less defined way to the visual stimulus compared to before TMS—the neurons did not show a preference for the same pathways used before TMS.
Following these observations, researchers then tried something different. They decided to show one visual stimulus before TMS, and a different visual stimulus after TMS. Researchers observed that when the cats watched a different visual stimulus after TMS, the brain formed new neuronal pathways. What’s more, is that the brain showed a preference for the new pathways even hours after a TMS session. This suggests that neurons are pliable and can “reset” and reorganize to form new neuronal pathways. This research also shows that TMS can encourage new neuronal pathway formation and therefore new habits of function. (4,5)
TMS Causes Changes in the Brain Beyond the Targeted Area
TMS directs magnetic pulses to stimulate the dorsolateral prefrontal cortex, but researchers know that TMS also indirectly modifies the behavior of deeper regions of the brain that form part of the limbic system. (6) The limbic system is a term used to describe a collection of structures in the brain that are involved in emotional functioning, like emotional processing, control, and expression. (7) The prefrontal cortex and the limbic system are connected through communication pathways that transmit the magnetic pulses applied to the dorsolateral prefrontal cortex to the limbic system.
What to Expect During a TMS Treatment Session
During a TMS treatment session, patients sit comfortably in a reclined chair. A doctor, nurse, or technician positions a magnetic coil over the scalp. While the TMS machine is turned on and delivering treatment, patients will hear a clicking sound (similar to that produced by an MRI machine).
Each TMS treatment session lasts approximately 20 minutes. TMS is an outpatient procedure that is performed while the patient is awake and alert. TMS does not require the use of anesthesia, allowing patients to drive themselves to work immediately following a treatment session. A full treatment course of TMS requires 9 weeks of therapy—6 weeks of 5 TMS sessions per week (administered once per day) and 3 weeks where patients receive fewer sessions each week, until they complete the treatment course (called the taper period).
TMS Provides Long-Term Results
In addition to improving depression symptoms without the need for medication, the positive effects of TMS have been shown to be long-lasting. How long TMS results last vary from patient to patient, but studies show that patients who see results with TMS are more likely to continue to see improvement in depression symptoms even one year after treatment.
One study observed the longevity of the effects of TMS in patients who received TMS treatment across the country. All participating patients were diagnosed with depression and did not see an improvement in their symptoms with antidepressants. To document symptom severity throughout the treatment course, participants completed an initial assessment before starting TMS, and followup assessments at 3, 6, 9, and 12 months after completing treatment. According to the final patient assessments, 62.5% of patients who saw an improvement in their symptoms and/or achieved remission at the end of TMS treatment continued to see an improvement in their symptoms even one year after treatment. (8)
More and More Patients With Depression are Choosing TMS Therapy: NYC is a Great Place to Have TMS
TMS is piquing the interest of many patients and gaining popularity because it improves depression symptoms without the need for medication, and therefore is not associated with the side effects of antidepressants. Patients looking for drug-free depression treatment that provides long-lasting results should consider TMS therapy. NYC and major cities across the US have clinics that offer TMS treatment. Talk to your doctor, psychologist, or psychiatrist about whether TMS therapy in NYC might be right for you.
- Nutt DN. Relationship of neurotransmitters to the symptoms of major depressive disorder. J Clin Psychiatry. 2008;69:Suppl E1:4-7. https://pubmed.ncbi.nlm.nih.gov/18494537/. Accessed August 10, 2020.
- C J Bench, K J Friston, R G Brown, L C Scott, R S Frackowiak, R J Dolan. The anatomy of melancholia–focal abnormalities of cerebral blood flow in major depression. Psychol Med. 1992;22(3):607-615. https://pubmed.ncbi.nlm.nih.gov/1410086/. Accessed August 09, 2020.
- Mesquita RC, Faseyitan OK, Turkeltaub PE, et al. Blood flow and oxygenation changes due to low-frequency repetitive transcranial magnetic stimulation of the cerebral cortex. J Biomed Opt. 2013;18(6):067006. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3678989/. Accessed August 09, 2020.
- Kozyrev V, Staadt R, Eysel UT, and Jancke D. TMS-induced neuronal plasticity enables targeted remodeling of visual cortical maps. Proceedings of the National Academy of Sciences. 2018;115(25):6476-6481. https://www.pnas.org/content/115/25/6476. Accessed August 09, 2020.
- Ruhr-University Bochum. What effect does transcranial magnetic stimulation have on the brain? Science Daily. Published June 5, 2018. https://www.sciencedaily.com/releases/2018/06/180605103511.htm. Accessed August 09, 2020.
- George MS, Stallings LE, Speer AM, Nahas Z, Spicer KM, Vincent DJ, Bohning DE, Cheng KT, Molloy M, Teneback CC, Risch SC. Prefrontal repetitive transcranial magnetic stimulation (rTMS) changes relative perfusion locally and remotely. Human Psychopharmacology: Clinical and Experimental. 1999; 14:161–170. https://onlinelibrary.wiley.com/doi/abs/10.1002/%28SICI%291099-1077%28199904%2914%3A3%3C161%3A%3AAID-HUP73%3E3.0.CO%3B2-2. Accessed August 10, 2020.
- Rajmohan V, Mohandas E. The limbic system. Indian J Psychiatry. 2007;49(2):132-139. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2917081/. Accessed August 10, 2020.
- Dunner, DL, Aaronson ST, Sackeim, HA, et al. A multisite, naturalistic, observational study of transcranial magnetic stimulation for patients with pharmacoresistant major depressive disorder: Durability of benefit over a 1-year follow-up period. J Clin Psychiatry. 2014;75(12):1394-401. https://pubmed.ncbi.nlm.nih.gov/25271871/. Accessed August 09, 2020.