Transcranial Magnetic Stimulation (TMS)
What Is TMS?
Transcranial Magnetic Stimulation (TMS) is a medical procedure in which a coil of wire is placed against the scalp and used to stimulate the brain through changes in a magnetic field, which create a small electrical current (American Psychological Association [APA], 2022a). It's considered non-invasive, since nothing enters the body — the coil simply rests on the outside of the head. That stimulation causes a temporary change in activity in a specific area of the brain (APA, 2022a).
You may also see it referred to as repetitive transcranial magnetic stimulation (rTMS), which simply means a series of pulses are delivered rather than just one (APA, 2022a). While the electrical pulses are strong, they're brief and don't cause pain (Rossini & Rossi, 2007).
The frequency of the pulses affects what happens in the brain. Generally speaking, low-frequency rTMS tends to decrease activity in the targeted brain area, while high-frequency rTMS tends to increase it (Brunoni et al., 2017).
Research has explored TMS as a potential treatment for a range of medical and mental health conditions, and studies consistently point to it being a safe technique (Rossini & Rossi, 2007). Some people do experience mild side effects, such as headaches or a tingling sensation on the face or scalp (Rizvi & Khan, 2019).
To test how well TMS works for a given condition, researchers often use what's called a sham-controlled study. In this design, one group of participants receives real TMS treatment, while a second group goes through the same procedure — including having the coil placed on their scalp — without any actual electrical current being delivered. This helps researchers isolate the effect of the treatment itself, separate from any placebo effect.
TMS and Major Depressive Disorder
Major depressive disorder (commonly called depression) affects more than 300 million people worldwide and is considered the leading cause of disability globally by the World Health Organization (Voineskos et al., 2019). It's diagnosed when five or more symptoms are present for at least two weeks, with at least one symptom being either a depressed mood or a loss of interest or pleasure in activities (APA, 2022b). Other symptoms can include changes in weight, sleep, or physical movement, fatigue, feelings of guilt or worthlessness, trouble concentrating, or thoughts of death or suicide (APA, 2022b).
The good news is that depression is largely treatable, and there are many evidence-based options. It's most commonly treated with talk therapy, medication, or a combination of both. Cognitive behavioral therapy in particular has strong research support (Cuijpers et al., 2013), and several other therapeutic approaches are effective as well. When depression doesn't respond adequately to talk therapy or medication, TMS is considered an appropriate next step (Gellersen & Kedzior, 2019).
Research into the biology of depression has pointed to an area of the brain called the left dorsolateral prefrontal cortex (DLPFC), where lower-than-typical activity appears to play a role in depression (Voineskos et al., 2019). When TMS is used to treat depression, high-frequency pulses are used to stimulate the DLPFC and increase activity in that region (Voineskos et al., 2019).
This type of treatment typically uses a coil shaped like a figure eight, and it's been FDA-approved for treatment-resistant depression since 2008 (Gellersen & Kedzior, 2019). A newer variation uses an H-shaped coil, which works in a similar way and has shown consistent, short-term antidepressant effects; this approach has been FDA-approved since 2013 (Gellersen & Kedzior, 2019).
TMS and Obsessive-Compulsive Disorder
A diagnosis of obsessive-compulsive disorder (OCD) requires the presence of obsessions, compulsions, or both (APA, 2022b). Obsessions are unwanted, recurring thoughts, images, or urges, while compulsions are repetitive behaviors or mental acts a person feels driven to perform in response to those obsessions (APA, 2022b). OCD can be highly distressing and significantly disrupt daily life — at home, at work, and in relationships.
Several evidence-based treatments exist for OCD. Currently, medication combined with talk therapy — particularly cognitive behavioral therapy — is the standard recommended approach (Berlim et al., 2013). But when medication and therapy don't provide enough relief, or medication side effects become difficult to manage, other options may be worth exploring.
Research is still developing in this area, but some evidence suggests the DLPFC — the same brain region linked to depression — may also play a role in OCD (Berlim et al., 2013). Because of this, rTMS has been studied as a potential treatment for OCD when other approaches haven't provided enough relief (Berlim et al., 2013).
What Else Is TMS Used For?
TMS is FDA-approved specifically for treatment-resistant depression, but ongoing research suggests it may also be helpful for other conditions when standard treatments haven't worked well enough, including:
• Obsessive-compulsive disorder (Berlim et al., 2013)
• Post-traumatic stress disorder (Isserles et al., 2013)
• Alcohol dependence (Mishra et al., 2010)
• Tobacco use disorder (Zangen et al., 2021)
References
American Psychological Association. (2022a). APA dictionary of psychology: Transcranial magnetic stimulation (TMS). https://dictionary.apa.org/transcranial-magnetic-stimulation
American Psychiatric Association. (2022b). Diagnostic and statistical manual of mental disorders (5th ed., text rev.).
Berlim, M. T., Neufeld, N. H., & Van den Eynde, F. (2013). Repetitive transcranial magnetic stimulation (rTMS) for obsessive-compulsive disorder (OCD): An exploratory meta-analysis of randomized and sham-controlled trials. Journal of Psychiatric Research, 47(8), 999–1006. https://doi.org/10.1016/j.jpsychires.2013.03.022
Brunoni, A. R., Chaimani, A., Moffa, A. H., Razza, L. B., Gattaz, W. F., Daskalakis, Z. J., & Carvalho, A. F. (2017). Repetitive transcranial magnetic stimulation for the acute treatment of major depressive episodes: A systematic review with network meta-analysis. JAMA Psychiatry, 74(2), 143–152. https://doi.org/10.1001/jamapsychiatry.2016.3644
Cuijpers, P., Berking, M., Andersson, G., Quigley, L., Kleiboer, A., & Dobson, K. S. (2013). A meta-analysis of cognitive-behavioural therapy for adult depression, alone and in comparison with other treatments. Canadian Journal of Psychiatry, 58(7), 376–385. https://doi.org/10.1177/070674371305800702
Gellersen, H. M., & Kedzior, K. K. (2019). Antidepressant outcomes of high-frequency repetitive transcranial magnetic stimulation (rTMS) with F8-coil and deep transcranial magnetic stimulation (DTMS) with H1-coil in major depression: A systematic review and meta-analysis. BMC Psychiatry, 19(1), 139. https://doi.org/10.1186/s12888-019-2106-7
Isserles, M., Shalev, A. Y., Roth, Y., Peri, T., Kutz, I., Zlotnick, E., & Zangen, A. (2013). Effectiveness of deep transcranial magnetic stimulation combined with a brief exposure procedure in post-traumatic stress disorder—A pilot study. Brain Stimulation, 6(3), 377–383. https://doi.org/10.1016/j.brs.2012.07.008
Mishra, B. R., Nizamie, S. H., Das, B., & Praharaj, S. K. (2010). Efficacy of repetitive transcranial magnetic stimulation in alcohol dependence: A sham-controlled study. Addiction, 105(1), 49–55. https://doi.org/10.1111/j.1360-0443.2009.02777.x
Rizvi, S., & Khan, A. M. (2019). Use of transcranial magnetic stimulation for depression. Cureus, 11(5), e4736. https://doi.org/10.7759/cureus.4736
Rossini, P. M., & Rossi, S. (2007). Transcranial magnetic stimulation: Diagnostic, therapeutic, and research potential. Neurology, 68(7), 484–488. https://doi.org/10.1212/01.wnl.0000250268.13789.b2
Voineskos, D., Blumberger, D. M., Zomorrodi, R., Rogasch, N. C., Farzan, F., Foussias, G., Rajji, T. K., & Daskalakis, Z. J. (2019). Altered transcranial magnetic stimulation-electroencephalographic markers of inhibition and excitation in the dorsolateral prefrontal cortex in major depressive disorder. Biological Psychiatry, 85(6), 477–486. https://doi.org/10.1016/j.biopsych.2018.09.032
Zangen, A., Moshe, H., Martinez, D., Barnea-Ygael, N., Vapnik, T., Bystritsky, A., Duffy, W., Toder, D., Casuto, L., Grosz, M. L., Nunes, E. V., Ward, H., Tendler, A., Feifel, D., Morales, O., Roth, Y., Iosifescu, D. V., Winston, J., Wirecki, T., Stein, A., Deutsch, F., Li, X., & George, M. S. (2021). Repetitive transcranial magnetic stimulation for smoking cessation: A pivotal multicenter double-blind randomized controlled trial. World Psychiatry, 20(3), 397–404. https://doi.org/10.1002/wps.20905