Most individuals have heard about repetitive Transcranial Magnetic Stimulation (rTMS) from a commercial, news story, advertisement, or a friend of a friend. However, a number of the people that I speak with either think that “the evidence isn’t there” for TMS, or think that “the success rate is too low.” People often misunderstand that success rate and efficacy of TMS due to a number of very important misunderstandings about medication and methodology. Many of the original clinical studies involving TMS show that it is successful about half the time, and can achieve full remission about a third of the time. This discrepancy is amplified by the fact that private clinics often boast significantly higher success rates than the original clinical trials, usually in the realm of 75-80% success and 50% remission. I will discuss the most likely explanations, as well as provide a bit of background.
Let’s pretend that a random individual is seeking his or her first ever treatment for depression. This random individual sees a psychiatrist, who prescribes them an average dose of a very common Selective Serotonin Reuptake Inhibitor (SSRI). What do you think is the likelihood that this SSRI works? The answer may surprise you.
According to the STAR*D study, which was a $35,000,000 clinical trial funded by the NIMH in 2006, the success rate for an initial anti-depressant trial is 27.5%. Unfortunately, this success rate also decreases by about 25% for each subsequent trial. This means that, by the time someone fails three medication trials, the probability that they will improve from a fourth medication trial is less than 7%. This rate is absolutely abysmal. Not to mention the fact that each trial substantially increases the likelihood of negative side-effects from anti-depressant medication, including:
- Erectile dysfunction
- Loss of sexual desire
- Weight gain and increased appetite
- Drowsiness and fatigue
- Blurred vision and dizziness
- Agitation and irritability
The Success of TMS
Returning to the success rate for TMS, we see that the success rate of TMS is actually higher than the success rate for first-trial anti-depressants. It is important to realize that the major clinical trials which examined the success rate for TMS (e.g., O’Reardon et al., 2007; George et al., 2010) used individuals who had already failed 4 or more anti-depressants in their lifetime. This means that the population involved in determining the efficacy of TMS was notoriously hard to treat. Had this population been given an anti-depressant medication trial, the effectiveness would probably have been around 5%, assuming another 25% reduction. So, now the initial numbers in the first paragraph start to make more sense. By definition, a ~50% success rate is 10x more effective than a 5% success rate.
TMS: More Effective In Practice
Laboratory-administered clinical research is often criticized for having such strict study criteria that many people who would otherwise qualify are deemed ineligible. Many of the clinical trials done to garner the approval of the FDA were with individuals who stopped taking all anti-depressant medication and going to therapy. Even though TMS can be used on people who are no longer taking anti-depressant medications, there are some studies In the “real world,” and at BH TMS, we encourage individuals to continue (or start) going to therapy. Many private TMS centers probably adhere to this same practice, which most likely improves the success of TMS. In fact, therapy and TMS can likely have synergistic effects. The symptoms of depression involve impaired insight, lack of emotional/cognitive flexibility, and cognitive fog. As TMS can help to relieve the cognitive symptoms of depression, individuals will be able to participate more thoroughly in their therapy, which will increase the chances of full remission from depression.
If you or your loved one are seeking relief for depression that has a high success rate, please give us a call at (866) 867-4519. We will work hard to make sure that your insurance will cover up to 100% of the cost.