The Role of TMS in Depression Treatment
Kira Stein, MD and Erin Yates, BSc
West Coast TMS Institute
Updated September 1, 2011
The Risks of Depression and Realities of Current Medical Treatments
Clinical depression is a common illness that can be disruptive, disabling and sometimes, life-threatening. Major depressive disorder is characterized by a persistent state of sadness and/or a lack of joy. It is often associated with feelings of excessive guilt or apathy, difficulties getting motivated, poor libido, low concentration and energy, disrupted sleep, feelings of sluggishness or restlessness, social isolation or withdrawal, and thoughts of death. Each year in the United States, more than 30,000 people suicide, 60% of which suffer from depression. Sadly, it is estimated that only 60% of people who suffer from depression obtain treatment, only half of which receive adequate treatment. Of the few who do receive traditional medication treatments, it has been estimated that approximately 15% persistently remain unresponsive.
While psychiatric medications change the brain’s neurochemistry in order to improve mood, more invasive techniques such as electroconvulsive therapy (ECT) and vagal nerve stimulation (VNS) for depression work by direct electrical stimulation of the nervous system. A different therapeutic approach has recently become available with transcranial magnetic stimulation (TMS). Unlike medication, TMS does not enter the circulatory system, and therefore is non-systemic and is associated with far fewer side effects. Different from ECT and VNS, TMS does not require an invasive procedure and uses magnetic pulses instead of direct electrical pulses to effect brain activity.
With so many treatment options, it can be difficult to determine which is best for a particular individual, and when it is appropriate to either abandon or augment drug therapy with another treatment approach.
Choosing the Next Step in Treatment*
Medication Remission and Response Rates
The 2006 seminal Sequenced Treatment Alternatives To Relieve Depression (STAR*D) study evaluated the success of psychiatric medications and augmentation strategies in the treatment of clinical depression. STAR*D was a prospective, randomized clinical trial of outpatients with nonpsychotic major depressive disorder. The STAR*D data illustrated that with first-line antidepressant treatment (such as Celexa/citalopram), about 30% of those with depression go into remission and an additional 20% experience significant but only partial improvement of their symptoms (total response of 50%). This leaves about 50% of patients as non-responders to first-line medication treatment. Switching to a second, different antidepressant had an even lower remission rate (a mean rate of approximately 21%). The success rate of further medication attempts steadily decreased until, by the fourth medication trial, the remission rate was below 10%.
TMS Remission and Response Rates
The number of unsuccessful medication trials relates to TMS therapy, as research shows that TMS is most successful when started after one adequate antidepressant trial (i.e., lasting 12 to 14 weeks) has failed. In this patient population, the depressive symptom remission rate is better with TMS therapy alone (1 in 3 patients remit; 1 in 2 patients respond) than in the comparable STAR*D population that switched to a second antidepressant medication. **
Furthermore, research shows that TMS by itself can also be considered to be at least as effective as an antidepressant combined with an augmentation medication such as another antidepressant or an antipsychotic agent, but without the risk of various unpleasant, potential side effects. Augmentation of an antidepressant drug with another medication can further increase the risk of systemic side effects, such as sexual dysfunction, weight gain, sedation, anxiety, or gastrointestinal difficulties. Antipsychotic agents, if used over a period of time, increase the risk of movement disorders, weight gain, high cholesterol and triglycerides, diabetes, and heart disease. TMS does not enter the blood stream, and therefore does not expose patients to the risk of systemic side effects.
Lower TMS Side Effect Profile Increases Chances of Adherence
The lower side effect profile, coupled with frequent, office-based, supervised administration of TMS, increases the likelihood of adherence to TMS treatment. One other lesson from the STAR*D study is that the risk of discontinuing medication treatment increases with each new medication attempt. While about 9% of patients discontinue their first trial of medication due to intolerable side effects, approximately 23% discontinue the second medication attempt, and by the fourth attempt, over 40% discontinue medication due to intolerable effects. TMS compares favorably to these numbers, as less than 5% of patients discontinue treatment due to adverse events, which are usually mild and transient scalp pain or irritation. Unlike antidepressant medication use, TMS is not associated with weight gain, sexual dysfunction, loose stools, constipation, nausea, and cognitive or sedating side effects. Under normal clinical use with the NeuroStar TMS device, the risk of experiencing a TMS-induced seizure is low, estimated to be 1 in 10,000 treatments, or 1 in 30,000 patients.
When to Introduce TMS Treatment
Studies also suggest that waiting for a depressive episode to worsen in severity before attempting TMS treatment can ultimately result in patients requiring more TMS treatments and longer treatment time frames, while experiencing less dramatic depressive symptom improvement than if they had started treatment sooner during their depression. Consequently, it is best to implement TMS both early on in a depressive episode and before several medication trials are attempted.**
While some patients respond quickly to low doses of antidepressant medications, often it takes several months of gradually raising a medication dose in order to learn whether or not the medication is effective for a particular patient. With TMS treatment for depression, patients who respond generally do so within 4-6 weeks, though some may require more or less treatments.
Treatment Must Be Individualized and Patient-Specific
In summary, patients who have insufficiently responded to one trial of an antidepressant should consider turning to TMS as a next step in the treatment for their depression. TMS alone appears to be more effective than a switch to a second medication, and is at least as effective as an antidepressant plus another augmentation agent, with significantly less potential side effects. TMS itself can also be used as an augmentation agent to ongoing, partially effective antidepressant medication, which may be an even more effective approach in treatment-resistant cases.
Ultimately, however, treatment decisions need to be based on a careful risk-benefit analysis of each individual’s current symptoms, psychiatric history and prior treatment experiences. While antidepressant medication treatment is frequently effective, TMS may be a better option for those who struggle with drug side effects and who are insufficiently responsive to medication.
* Comparison data come from independent but clinical trials; head-to-head studies of TMS and antidepressant medication have not been conducted.
** The rate of response and remission to TMS therapy for depression has not been studied in depressed patients who have not had a complete trial of any antidepressant medication.
Referring to The West Coast TMS Institute:
If you are seeking a TMS referral partner, we welcome the chance to meet with you to discuss our team-based approach to caring for your patients. We look forward to hearing from you (818-855-1694) to set up a time to talk or visit the Institute.
Should you wish to refer a patient for evaluation for TMS treatment, please download a TMS referral form by Clicking Here.
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