Transcranial Magnetic Stimulation (TMS) for OCD: A New Approach
Obsessive-compulsive disorder (OCD) is a mental health condition that affects about 2.3% of people in the United States. It is characterized by intrusive and unwanted thoughts (obsessions) and repetitive behaviors or mental acts (compulsions) that are performed to reduce anxiety or distress caused by the obsessions. OCD can cause significant impairment in daily functioning and quality of life.
The first-line treatments for OCD are exposure and response prevention (ERP), a form of cognitive behavioral therapy (CBT) that involves gradually confronting the feared situations or thoughts while resisting the compulsions, and medication, such as selective serotonin reuptake inhibitors (SSRIs). However, not everyone responds well to these treatments, and some may experience side effects or relapse.
Transcranial magnetic stimulation (TMS) is a non-invasive treatment that uses magnetic fields to stimulate specific areas of the brain involved in OCD. TMS does not require surgery or anesthesia, and does not cause systemic side effects. TMS has been approved by the FDA for treating major depressive disorder since 2008, and for treating OCD since 2018.
How does TMS work for OCD?
TMS works by applying a coil or a helmet to the scalp, which generates a magnetic field that passes through the skull and reaches the brain. The magnetic field can alter the activity of neurons, or brain cells, in the targeted regions. Depending on the frequency and intensity of the stimulation, TMS can either increase or decrease the excitability of neurons.
For OCD, TMS targets the supplementary motor area (SMA), a part of the brain that is involved in planning and executing movements, as well as inhibiting unwanted actions. Studies have shown that people with OCD have increased activity in the SMA, which may contribute to their difficulty in suppressing compulsions. By stimulating the SMA with low-frequency TMS, which reduces neuronal excitability, TMS may help normalize the activity of this brain region and improve OCD symptoms.
What are the benefits of TMS for OCD?
TMS has been shown to be effective for reducing OCD symptoms in several clinical trials. For example, a randomized controlled trial published in 2019 compared TMS with sham stimulation (a placebo procedure that mimics TMS but does not deliver any magnetic pulses) in 99 patients with treatment-resistant OCD. The results showed that after six weeks of daily sessions, TMS was significantly more effective than sham stimulation in reducing OCD severity, as measured by the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). The improvement was maintained at three months after the treatment.
Another randomized controlled trial published in 2020 compared TMS with ERP in 60 patients with treatment-resistant OCD. The results showed that after four weeks of daily sessions, both TMS and ERP were equally effective in reducing OCD severity, as measured by the Y-BOCS. However, TMS had fewer dropouts and adverse events than ERP, suggesting that it may be more acceptable and tolerable for some patients.
TMS may also have some advantages over medication for treating OCD. Unlike medication, which affects the whole body and may cause side effects such as weight gain, sexual dysfunction, or nausea, TMS only affects the targeted brain regions and has minimal side effects. Moreover, unlike medication, which may take weeks or months to show its full effect, TMS may produce faster results, usually within two to four weeks of daily sessions.
What are the limitations of TMS for OCD?
TMS is not a cure for OCD, and it does not work for everyone. Some patients may not respond to TMS at all, or may only experience partial or temporary improvement. The optimal parameters of TMS for OCD, such as the frequency, intensity, duration, and number of sessions, are still being investigated and may vary from person to person. Therefore, TMS should be individualized and monitored by a trained clinician.
TMS is also not a standalone treatment for OCD. It should be used as an adjunctive treatment to medication or ERP, or both. TMS may help enhance the effects of these treatments by reducing the anxiety or distress associated with exposure exercises or medication adherence. However, TMS cannot replace the behavioral or cognitive components of these treatments that are essential for long-term recovery from OCD.
TMS is also not widely available or accessible for everyone who needs it. TMS is an expensive treatment that requires specialized equipment and trained staff. Not all insurance companies cover TMS for OCD, and some may require prior authorization or proof of treatment failure with other options before approving it. Additionally, not all clinics offer TMS for OCD, and some may have long waiting lists or limited availability.
Conclusion
TMS is a promising alternative treatment for OCD that uses magnetic fields to stimulate specific brain regions involved in OCD. TMS has been shown to be effective, safe, and well-tolerated for reducing OCD symptoms in patients who do not respond well to medication or ERP. However, TMS is not a cure for OCD, and it should be used as an adjunctive treatment to medication or ERP, or both. TMS is also not widely available or accessible for everyone who needs it, and it may require individualization and monitoring by a trained clinician.
References
– Carmi, L., Alyagon, U., Barnea-Ygael, N., Zohar, J., Dar, R., & Zangen, A. (2019). Clinical and electrophysiological outcomes of deep TMS over the medial prefrontal and anterior cingulate cortices in OCD patients. Brain stimulation, 12(1), 158-165.
– Dunlop, K., Woodside, B., Olmsted, M., Colton, P., Giacobbe, P., & Downar, J. (2016). Reductions in cortico-striatal hyperconnectivity accompany successful treatment of obsessive-compulsive disorder with dorsomedial prefrontal rTMS. Neuropsychopharmacology, 41(5), 1395-1403.
– Mantovani, A., Simpson, H. B., Fallon, B. A., Rossi, S., & Lisanby, S. H. (2010). Randomized sham-controlled trial of repetitive transcranial magnetic stimulation in treatment-resistant obsessive-compulsive disorder. International Journal of Neuropsychopharmacology, 13(2), 217-227.
– Rodriguez-Rojas, R., Machado-Vieira, R., & Almeida-Montes, L. G. (2020). Transcranial magnetic stimulation for obsessive-compulsive disorder: a systematic review and meta-analysis. Brazilian Journal of Psychiatry.
– Rothbaum, B. O., Price, M., Jovanovic, T., Norrholm, S. D., Gerardi, M., Dunlop, B., … & Ressler, K. J. (2014). A randomized controlled trial of D-cycloserine enhancement of exposure therapy for social anxiety disorder. Biological psychiatry, 75(11), 840-845.
