Treatment resistant major depression, defined as three or more failed medication trials, is a serious clinical issue. In multiple controlled studies, patients who have already failed several medication trials responded significantly better to rTMS than sham treatment. In the STAR-D trial, the antidepressant remission rate dropped significantly with each failed medication. As shown in the following chart, once a patient has failed three medication trials, rTMS is almost three times as likely as a fourth medication to produce remission. 1
In observational studies, up to 58% of patients are responders and 37% remitters. The effect is durable but, as major depression tends to be a chronic illness, eventually many patients do require follow-up treatments. Well over 80% of the time these follow-up treatments are successful, and often the treatment course is significantly shorter. 2
Side effects include mild headaches, site pain, muscle tension or twitching, and GI upset. There is a low incidence of seizures, with an estimated seizure risk of 0.003% per treatment, or 0.1% of patients. The discontinuation rate tends to be approximately 10%, as compared with a 20%-30% rate for medication trials.
Some Contraindications of TMS Therapy
Repetitive Transcranial Magnetic Therapy should not be used on individuals under the age of 18; pregnant women; epileptic individuals; those with a family history of convulsions; individuals with severe heart disease; individuals with non-removable magnetic sensitive metal objects in their heads or near the magnetic coil; or individuals with pacemakers; implantable cardioverter defibrillators; vagus nerve stimulators; or ferro-magnetic ocular implants.
References: 1. Avery, David H., Keithe E. Isenberg, Shirlene M. Sampson, Philip G. Janicak, Sarah H. Lisanby, Daniel F. Maixner, Colleen Loo, Michael E. Thase, Mark A. Demitrack, and Mark S. George.
“Transcranial Magnetic Stimulation in the Acute Treatment of Major Depressive Disorder.” J. Clin. Psychiatry The Journal of Clinical Psychiatry 69.3 (2008): 441-51. Web. 2. Carpenter, L. et al. “Transcranial Magnetic Stimulation (TMS) for Major Depression: A multisite, naturalistic, observational study of acute treatment outcomes in clinical practice” (2012). 3. Herwig U. et al. Biol. Psychiatry. (2001): 50(1): 58-61. 4.